..‘T MICHIGAN STATE UNIVERSITY Ll l l llll ll l l lllllflllllllll 3 1293 10668 54 .53 fl I l 4 ( ll This is to certify that the thesis entitled Mineral Interrelationship Between Soil—Plant—Animal in the Northern and Southern Regions of Veracruz, Mexico presented by Victor Mbnroy Ayon has been accepted towards fulfillment of the requirements for M.S. degfiWin Animal Science max/l M Major professor DNW’L 0-7 639 Liming-w \ WW fitate University - v RETURNING MATERIALS: PV1£3{_) Place in book drop to LIBRARIES remove this checkout from - your record. FINES will be charged if book is returned after the date stamped below. W “W’ 000 000; aw'a'7‘a7w4 H53-4 «58 J 6 5 u , ‘EQTEVQ are». _,______,_._- , I L MINERAL INI‘ERREIATIONSHIP 3mm SOIL-PLANr-ANIMAL IN m: NOW AND 30mm REGIONS OF VERACRUZ, MEXICO by Victor Morrroy Ayon A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Animal Science 1982 m C [9009 ABSTRACT MINERAL INIERREIATIONSIIIP 13mm SOIL-PIANr-ANIMAL IN THE NORTHERN AND SOUTHERN REGIONS OF VERACRUZ, MEXICO By Victor Monroy Ayon The mineral soil-plant-animal interrelationships were studied in the Nbrth and South regions of the state of Veracruz, Mexico. Low soil phosphorus, magnesium, copper and selenitnlconcen- trations were found in both regions, where 892, 182, 722, and 21% of the samples were deficient, respectively. In Region I (South) 752 and 56% of Pangola and Llano grass samples were deficient in calcitnn 882 and 94% in phosphorus, 31% and 242 in magnesium, 43% and 492 in copper, and 43% and 53% in seleniun, respectively. In Region II (North) 11% and OZ of Star and Guinea grasses were deficient in calciun, 27% and 8% in phosphorus, 772 and 772 in magnesiun, 25% and 15% in copper and 66% and 61% in selenium, respectively. Mineral deficiencies in grasses were reflected in the cattle grazing on it. Deficiencies of calcium, phosphorus, magnesium, COpper and seleniiniwere detected with different degrees of incidence in cows, heifers and calves. IUMYI‘UI'HER ANAMARIAAYON AND 'lU'I'HEME'MDRYOFMYFATHER VICIUR IVDNROY whose sacrifices, encouragement, support and understanding throughout the years made possible the accomplishment of this goal. AWWIEDCNENI'S The author wishes to express his most sincere and deepest gratitude to his major professor, Dr. Robert M. Cook, whose con- tinuous academic guidance, patience and moral support made this present work possible. Gratitude is also extended to the other members of his committee, Drs. John T. Huber, John Gill and Howard Stowe for their suggestions during the preparation of this manuscript. Thanks are also given to Dr. M. Villareal for his invaluable assistance in the computer analysis. The author is also grateful to Dr. H. Roman Ponce for his invaluable support during the sampling period. Special apprecia— tion is due to the Cattlemen's Associations and individual farmers from the two regions studied. Appreciation is extended to the fellow graduate students, laboratory personnel for their assistance, but especially to all the friends who enriched his life during these years. iii TABLE OF CONTENTS Page List of Tables ........................................... vi List of Abbreviations .................................... ix INTRDDLIII‘ION ............................................ . 1 LITERATURE REVIEW ........................................ 4 Mineral Availability .............................. 6 Calcium and phosphorus .......................... 13 Magnesium ....................................... 15 Iron ............................................ l6 Selenium ........................................ 17 Zinc ............................................ 20 Potassium ....................................... 22 Mineral Interactions .............................. 24 Copper—molybdenum— sulphate ...................... 28 Sulphur—selenium ................................ 34 Zinc—copper-manganese ........................... 35 Zinc and cadmium ................................ 38 MATERIALS AND METIDDS .................................... 39 location of the Study Area ........................ 40 Collection and Preparation of Samples ............. 40 Soil ............................................ 41 Forages ......................................... 4l livestock ....................................... 42 Soil Analysis ..................................... 42 Forage Analysis ................................... 44 Blood and Serum Analysis .......................... 44 Statistical Analysis .............................. 45 RESULTS AND DISCUSSION ................................... 47 Soil-Plant-Animal Calcium Relationship ............ 47 Soil-Plant-Animal Phosphorus Relationship ......... 5'1 Soil-Plant—Animal Magnesium Relationship .......... 55 Soil—Plant-Animal Potassium Relationship .......... 58 Soil-Plant-Animal Copper Relationship ............. 62 Soil-Plant-Am’mal Iron Relationship ............... 65 Soil-Plant-Animal Selenium Relationship ........... 65 Soil—Plant-Animal Zinc Relationship ............... 73 iv v Soil Cobalt Relationship .......................... 76 Soil pH Relationship .............................. 77 Grass Dry Matter Relationship ..................... 79 Blood Hemoglobin and Hematocrit Relationship ...... 80 SIM’IARY AND COMILUSIONS .................................. 83 APPENDIX ................................................. 87 117 BIBLIOGRAPHY ............................................. LIST OF TABLES Table l. Mean Calcitm Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle from Northern (Region II) and Southern (Region I) Veracruz, Mexico .......................................... 2. Mean Phosphorus Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle from Northern (Region II) and Southern (Region I) Veracruz, Mexico .......................................... 3. Mean Magnesium Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle From Northern (Region II) and Southern (Region I) Veracruz, Mexico .......................................... 4. Mean Potassium Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle from Northern (Region II) and Southern (Region I) Veracruz, Memlco .......................................... 5. Mean Copper Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle from Northern (Region II) and Southern (Region I) Veracruz, Mexico .......................................... 6. Mean Iron Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle from Northern (Region II) and Southern (Region I) Veracruz, Mexico .......................................... 7. Mean Seleniun Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle from Northern (Region II) and Southern (Region I) Veracruz, Mexico .......................................... 8. Mean Zinc Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle from Noth (Region II) and Southern (Region I) Veracruz, Mexico .......................................... 9. Mean Soil pH, Soil Cobalt, and Grass Dry Matter Values from Northern (Region II) and Southern (Region I) Veracruz, Mexico ..................... Page 49 53 57 6O 64 67 71 74 78 Mean Hemoglobin and Hematocrit Values of Grazing Cattle from Northern (Region II) and Southern (Region I) Veracruz, Mexico ..................... 81 Mean Calcium Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle for Indivi- dual Farms from Northern (Farms 1—6) and Southern (Farms 7-12) Veracruz, Mexico .......... 87 Mean Phosphorus Concentrations of Soils, Grasses and Blood Sera of Grazing Cattle for Individual Farms from Northern (Farms 1-6) and Southern (Farms 7- 12) Veracruz, Mexico .......................................... 88 Mean Magnesiun Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle for Indivi- dual Farms from Northern (Farms 1-6) and Southern (Farms 7-12) Veracruz, Mein'co .......... 89 Mean Potassium Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle for Indivi- dual Farms from Northern (Farms 1-6) Southern (Farms 7-12) Veracruz, Mexico ................... 9O I‘han Copper Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle for Indivi- dual Farms from Northern (Farms 1-6) and Southern (Farms 7-12) Veracruz, Mexico .......... 91 I‘han Iron Concentrations of Soils, Grasses and Blood Sera of Grazing Cattle for Individual Farms from Northern (Farms 1-6) and Southern (Farms 7-12) Veracruz, Mexico ................... 92 Mean Selenium Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle for Indivi— dual Farms from Northern (Farms 1-6) and Southern (Farms 7-12) Veracruz, Mexico .......... 93 Mean Zinc Concentrations of Soils, Grasses, and Blood Sera of Grazing Cattle for Indivi- dual Farms from Northern (Farms 1-6) and Southern (Farms 7-12) Veracruz, Mexico .......... 94 Mean Soil Cobalt Concentrations, Soil pH, and Grass Dry bhtter for Individual Farms from Northern (Fanns 1-6) and Southern (Farms 7-12) Veracruz, Mexico ................................ 95 A10. A11. A13. A14. A15. A16 . viii Mean ngobin and Hematocrit Values of Grazing Cattle for Individual Farms from Northern (Farms 1-6) and Southern (Farms 7-12) Veracruz, Mexico .......................................... Correlation Coefficients Between Different Soil Minerals and Soil pH from Northern (Region II) and Southern (Region I) Veracruz, Mexico ........ Correlation Coefficients Between Different Grass Minerals and Dry Matter from Northern (Region II) and Southern (Region I) Veracruz, Mexico.... Correlation Coefficients Between Different Grass Minerals or pH in Soils and Minerals in Forages from Northern (Region II) and Southern (Region I) Veracruz, Mexico ................................ Correlation Coefficients Between Minerals in Soils arri Minerals in Serum and Between Soil Minerals and Hemoglobin or Hematocrit from Samples of the Northern (Region II) and Southern (Region I) Veracruz, Mexico ................................ Correlational Coefficients Between Minerals in Grasses and Minerals in Serum and Between Grass Minerals and Hemoglobin and Hematocrit from Samples of the Northern (Region II) and Southern (Region I) Veracruz, Mexico ............ Correlational Coefficients Between Minerals in Sera of Cows, Heifers and Calves, from Samples of the Northern (Region II) and Southern (Region I) Veracruz, Mexico ............ 96 97 103 108 112 114 116 LIST OF ABBREVIATIONS sgaaagase Calves Cows Dry Matter Grass Hemoglobin Heifers Hematocrit Region Soil Compound Abbreviations should be read as follows: CASe COK CRAP Calves Selenium Cows Potassium Grass Phosphorus INTRODUCTION Runinants long have had a special role in human economy, providing meat, milk, leather, and wool. They are also a major source of power, and transportation in many parts of the world. Because of the presence of rumen microorganisms, ruminants are able to utilize cellulose to produce higi quality Inman food. Runinants, like all other animals, must receive all of the essential dietary nutrients in optimal amounts to maintain health, and to grow and reproduce with maximal efficiency. If nutrients are imbalanced, normal development will cease. Proper nutrition of the rtmen microorganisms is essential for digestion of feed in the rumen. In countries other than those of western Europe and North America, a large proportion of annuals obtain food entirely from pasture and receive no supplements for the whole or the greater part of the year. In pastoral systems wide variations in quality and quantity of forages exist. These variations depend on many environ- mental factors as well as management practices. In Latin America, livestock production is based exclusively on grasslands with minimal or no supplementation. Native grasses provide the nutrients required to support reasonable animal per- formance. However, climatic and seasonal factors modify the amount and quality of the nutrients available in the forage. The primary limitation in animal production is lack of forage during the dry 1 season. Adverse effects on cattle depend on the severity and dura— tion. Weight losses are large among all classes of cattle. Deaths a‘e substantial, particularly for older cows and for calves born during the dry season. . Animal reproduction rates are low. Thirty to 507.. of the cows calve per year (17). Steers require 4 to 6 years to obtain the desired market weight, with annual gains in weight between 50 and 100 kg. Malnutrition is commonly believed to be the most important limitation to ruminant livestock production in tropical countries. Wasting diseases, loss of hair, depignented hair, noninfectious abor- tion, diarrhea, anemia, loss of appetite, tetany, low fertility and pica are clinical sigis suggestive of nutrient deficiencies. Much of the work on nutritional deficiencies has been related to minerals. Becoming more generally recognized among animal pro- ducers are the facts that concentrations of soil minerals and their availability to plants are strongly related to the health of animals fed on plants grown on deficient soils. Studies of mineral deficiencies are important for making available information to livestock producers. Mexico has a National Soil Mapping program to determine mineral adequacies in regions important for livestock production. This thesis is a study of the mineral status of soils, plants, and cattle in two different regions in the state of Veracruz, Mexico. The objectives of this experiment are: 1) To determine the mineral status of grazing animals in two different regions in the state of Veracruz, Mexico. 2) To find appropriate methodology for sampling soils, plants and animals. LITERATUREREVIEW Dining recent years, knowledge of nutritional physiology of minerals has developed rapidly. This review will be confined to aspects of mineral nutrition that involve minerals in soils, plants and animals. Minerals are very important in the metabolism of organisms. They are required for biosynthesis of essential nutrients for bones and teeth, as constituents of proteins and lipids and as cofactors for enzyme systems of the body. They are also related to osmntic pressure and acidbase equilibria, and have effects on the irrita- bility of muscles and nerves. Evolution has selectively established certain elements as essential for the functioning of living organisms. At the present time 22 of the 90 naturally occurring elements are known to be essential for animal life (129). They can be divided into two groups based on the amnunts needed to satisfy the requirements of each elements. I) Macroelements are expressed in milligrams or grams required in daily ration. They are: calcitm (Ca), phosphorus (P), magnesium (Mg), sodium (Na), sulfur (S), potassium (K), and chloride (C1). II) Microelements, or trace elements, are eiqaressed in parts per million (ppm). They are: iron (Fe), zinc (Zn), c0pper (Cu), manganese (Mn), nickel (Ni), cobalt (Co), molybdenum (Mo), selenium (Se), chromium (Cr), iodine (I), fluoride (F), tin (Sn), silicon (Si), vanadium (V), and arsenic (As). 4 Differemt criteria of essentiality have been used to establish the classification of elements (14, 79, 80, 105, 116). Schutte relates the criteria of essentiality as follows: An element cannot be considered essential, unless: - A deficiency of it makes it impossible for plant and animal to complete the vegetative or reproductive stage of its life cycle. - Such deficiency is specific to the element in question, and can be corrected or prevented only by supplying this element. - The element is directly involved in the nutrition of the plant or animal, quite apart from its possible effects in correcting some microbial or . chemical condition of the external medium. An element is considered by Mertz (79) to be essential if its deficiency consistently results in impairment of a function from optimal to suboptimal. Further classification for trace elements is done and it is justified for a few elements such as lead, cadmium, and mercury because their biological significance is confined to toxic properties (129). Verchikov (132) describes three zones of action: a) Biologi- cal, which expresses the optimal supplementation and normal function. b) Pharmacological, where increasing doses of the element produce a phase of irritation and stimulation of some functions. c) Toxi- cological, where higher doses produce signs of toxicity. Domestic animals can be exposed to potentially toxic mineral elements from.severa1 sources. High.concentration.in the diet can result in.acute toxicities. Also lower levels of certain minerals may be consumed over extended periods of time and result in tissue accumulation of the element leading to chronic toxicity. Amnerman (2) suggested that a curplete evaluation of mineral toxicity requires information on concentration, form.and distribution of the element in water, soils, and air. An element is known as toxic if it impairs growth.or metabolism of an.organ when.it is supplied above certain concentrations. All elements are toxic at high concentrations and some are notorious poisons even at low concentrations. A.good example is copper. An.optimal range of concentration (sometimes narrow) exists for the supply of each element to each organism. Smith 1962 (cited by Bowen) showed the ideal curve relating growth.and concentration of a nutrient, in whiCh.the difference in concentration of a certain element between minimal dietary requirement and maximal safe level or'maxbmal tolerance level varies considerably under different conditions. To discuss the complexity of biological toxicity of one ele- ment requires the new concomitant discussion of the effects of a deficiency of another interacting element or elements (19). Mineral Availability It is generally recognized that the concentration of a mineral element in a particular feed or ration has little signifi— cance unless it is qualified by a factor indicating the biological avilability of the element to animals. Physiological availability, or potency, is influenced by two principal factors. One is the chemical form in which the element is ingested. The second factor is the ratio or pro- portion that the dietary conceitration of that element bears to other elenents or compomds with which it reacts metabolically (130) . A nuber of terms have been deve10ped to describe certain specific measurements. These include percent utilization, perceit apparent digestibility, percent of absorption and others. The term biological availability is used as a measure of the ability of the element or ion mder consideration to support some physiologi- cal process. Biological availability data are reported in numerical terms relative to a previously selected. reference standard (103). For example, ferrous sulfate is usually used as a standard for determining the bioavailability of iron, dicalcium or monosodium phosphate as a standard for phosphorus and sodium selenite as standard for selenium. The bioavailability of a mineral element may be measured by total body retention, specific tissue incorporation or specific Compound synthesis. The bioavailability of calcium and phosphorus may be measured by element balance or by incorporation into bone; iron might be measured best by generation or erythocytes or hemo- globin synthesis and selenium by activity of glutathione peroxidase (81). The bioavailability of calcium, magnesium, iron and zinc in commercial mineral complexes were determined by Ranhotra _e_t_:_ a}; (110). For Fe determination, hemoglobin depletion—repletion technique was used and for the other elements, the retention of minerals in bone (femur) was used as a test criterion. Large amounts of literature on mineral availability deals with factors that influence the utilization of the elements in various ways. Some important factors for animals are type of ration, chemical form of the element, age and sex of the animal, fat, protein and energy levels of the ration, plane of nutrition, enviroment, hormone concentrations, diseases and parasites, and interaction with other minerals or nutrients and cheleting agents . Livestock obtain minerals primarily from two sources, feed ingredients and mineral supplements. Water may or may not provide minerals, and air rarely contributes significant amounts. Because the majority of minerals are obtained through consumption of forages, grains and by-products, it is well to consider soil factors that influence the mineral content of plants. Of the total mineral concentration in soils only a fraction is taken up by plants. The availability of minerals in soils depends upon their effective con— centration in soil solutions. Lindsay (76) presented a dynamic situ- ation. As the plants remove minerals from the soil solution, equilib- rium may be restored by the release of minerals from the exchange complex. Korte e_t_ a_l (73) studied the relative mobilities of trace elements in soils. They pointed out that it should be possible to predict qualitatively the migration of an element through the soil on the basis of physical and chemical properties of the soil. Among them, soil texture, surface area, the content of hydrous oxide and free lime provide the most useful information for predicting retention of soil elements. Soil properties and conditions markedly affect the uptake and utilization of minerals by plants. The supply of ions to plant roots is controlled by processes of convection, diffusion and inter- ception. The root also produces exudates of organic camplex anions to dissolve fixed metals for absorption (52, 100, 139). Beeson (9) summarized studies on properties of soil and other factors that influence plant growth and mineral availability. He pointed out that soil consists of three phrases, a gaseous phase, a liquid phase and a solid phase. Minerals are found in the solid phase; to be available to the plants they must be released from the solid phase by hydrolysis. Examples are calcium, magnesium and potassium. The uptake of elements by plants is directly related to the concentration in the liquid phase. Most of the released elements will be attached to the surfaces of the colloidal particles of soils, mainly by base exchange reaction with hydrogen ions. Microelements such as copper, cobalt and zinc undergo the same reactions as macroelenents. However, the microelements are greatly influenced by soil organic matter. Although there appears to be a general relationship between content of organic matter in soils and micronutrient content, most organic soils are very low in copper (15). There is continuous interchange of the nutrient cations in the liquid phase with the cations absorbed on the colloidal surfaces. The pH has profouid influence on the solubility Of mineral elements and their availability to plants. Very acid 10 or alkaline soils (4.5 and 8.5 respectively) may result in excessive or limited solubility of an element. In general, calcium content is adequate for most field crops and pasture. Even acid soils contain sufficient calcium for reasonable plant growth which on acid soils is usually caused by excess of mrmganese, iron and aluminium rather than deficient cal- ciLm. The most important factors that determine the mineral uptake by crops and pastures were listed by Fleming (1973). These include soil acidity, moisture or drainage conditions, soil temperature and seasonal effects, plant genus, species and variety. On the other hand, the concentration of the mineral elements in plant tissue can vary over a wide range, depending upon availability of the ele- ment in soil, cutural practices, proportion of plant parts and climatic factors (9). Climatic factors, principally rainfall and temperature, play important roles in the absorption and uptake of the mineral nutrients from the soil. Climate is important but it indirectly influences the nature of the vegetation in a special region which has a marked effect on soil type. Low soil temperatures limit the uptake of minerals by plants (9). In the humid tropics, forage growth is continuous and very rapid, but seasonal. Very high annual yields may be obtained (17). It is logical that forage grown under abundant rainfall and high humidity should contain more water. The relationship between rainfall and nutritional value of tropical forage shows that grasses are more ll nutritious in the wet than.in.the dry season. 'Positive correlations exist between.rainfall and crude protein, silica free ash, and nitrogenrfree-extract in forages. A.negative correlation exists between crude fiber content and rainfall (53). 'Marked decline in whole plant mineral concentration.with.advancing maturity has been feund. Underwood (129) reported a concentration increase ‘with.advancing1maturity of the plant of Si, Al, Cr, and a decrease in Cu, Zn, Co, Ni, Mo, Fe, and Mn. Vegetational factors that determine the mineral content of plants includespecies and state of growth” 'With most plant species the differences in mineral content are smaller among the seeds than those which occur in the vegetative plants. Even when the mineral content of feeds is known it is not an indicator of the availability of minerals to body tissue. Minerals in plants are largely in organic form whereas most of those in supplemnts are in inorganic form. It has been established that minerals frcm most supplements are used more efficiently than minerals from natural feedstuffs. Over 50% of manganese, cobalt and zinc in dried grass may be soluble in water; their solubility in the rumen is also very high. The forms in which minerals are present in.plants may deter- mine the efficiency of utilization within the digestive tracts of animals (2, 14, 128). Also, the availability of minerals may be affected by the presence of interfering compounds, both organic and inorganic, by the maturity of the plant and the type of plant and fertilization. 12 As with the uptake of elements by plants, only a fraction of the total minerals present in the diet are utilized for main- tenance and production in the animal body, while the remainder is generally recycled as excreta directly or indirectly to the pas- ture (112). Mills (87) pointed out that tie availability of ten of the most important essential elements could be modified by con- centrations of at least 15 other dietary compounds and 21 inter- actions influencing availability of trace elements. The essential processes to be considered when discussing availability and absorption of trace metals are, 1) chemical form of tie element in food, 2) stability and solubility during digestion, 3) formation of new species with metal binding components of gastro- intestinal secretion, and 4) active or passive absorption of the final product from the intestinal luren and the release of its metal component of specific mucosal carriers involved in transport. The absorption of each elerent depends primarily on the element itself, but also on factors such as dietary concentration of other nutrients. Once absorbed an element is deposited throughout the body or in a target organ (43). Factors that have a great influence on the availability of mineral eleneits for absorption from digesta are water content, pH and location in the tract (32). Flow rates of digesta are also important in mireral absorption. Sites of intestinal absorption for a given substance become more distal when the concentration of that substance increases in the diet (13). 13 Calcium and Phosphorus Availability of phosphorus to crops is low in practically all soils after tl'ey have been cropped for many years. Phosphorus deficiencies em'e common in gray, brown and black soils, and in older soils with low organic matter (140). Information on phosphorus availability is presented separately for each of tie major animal species (81, 103, 104). The value of phosphorus of plant origin has been questioned for years. Phytate phosphorus, as it occurs on plants, generally is regarded as being substantially less biologically available than most forms of inorganic phosphorus. Phytate combines with many elerents (Ca, Mg, Zn, Mn, as well as P) making them to some degree unavailable to the animal. The biological availability of the phosphorus in phytin varies depending on the species and age of the animal. For cattle only 607; of the phosphorus in this form is available (4). Also it is known that older animals have greater ability to utilize the phytate form of phosphorus, because more of the enzyme phytase is present in the gUt. Another factor influencing phytate phosphorus availability is calcium level. _ Generally, as calcium increases in the diet, phytate phosphorus becomes less available. Vitamin D may affect phytate phosphorus by its effect on calcium. Forages are characteristically low in phosphorus. Soils in areas of high rainfall are normally low in phosphorus and offer minerals (37) . Soils in the humid tropics are cferacteristically acidic, with high amounts of exchangeable aluminum, which forms 11+ complexes with phosphorus, making it unavailable to plants (1&0). The value of a feedstuff as a source of calcium depends not only on its calcium content but also on the amount that the animal can extract and retain for its own use. Many factors influence the absorption and retention of calcium, such as age of animal, level of vitamin D, concentrations of blood hormones , amount and form of calcium fed, and calcium status of the animal. In ruminants wide differences in biological availability of calcium sources have been reported (A). Calcirm from inorganic sources have appeared to be utilized more efficiently than alfalfa and orchard grass hays. Peeler (103) working with 15 different organic and inorganic sources of calciLm, pointed out that true digestibility of calcium was greater in‘young cattle than in mature steers. The bioavailability of calcium in some forages has also been determined (81, 104). Brazilian workers found that the calcium content of grasses was enough to supply the calcium required by grazing ruminants. On the other hand, phosphorus concentration in most forages was insuffi- cient to prevent chronic deficiency in cattle. The low phosphorus level became a serious problem during the summer ((47). Blue and Tergas (12) reported that nitrogen fertilization produced a more rapid decline in phosphorus content and that the rate of decline is proportional to nitrogen added. They also reported that calcium and magnesium concentrations declined during the dry season. For calcium that result could be expected because much of it is incorporated into the cell wall tissue. The Ca:P 15 ratio increases from less than 5:1 to more than 10:1 during the dry season, wiu’ch by far exceed the recommended values, especially with low phosphorus levels. For grazing cattle, the most prevalent mineral deficiency aromd the world is lack of phosphorus. Twenty one Latin American and Caribbean comtries reported deficiencies (90). Magesium Several criteria have been used to measure magesium avail— ability such as apparent absorption and blood plasma levels, percent Lm‘inary excretion of magnesium intake and more recent studies involving complete balance trials. The availability of herbage magnesium increases as the herbage matured. A negative correlation was found between crude protein content and magnesium. Moreover, heavy application of nitrogen and potassium on pasture have a negative influence on the availability of magresiun (67). Magnesium availability in concentrate feed is ranging up to (+07. and from 107, to 407., in grains and forages (104). Only a relatively small proportion of the total magnesium present in agricultural soils is available to the plants. The level of exchangeable Mg is frequently placed at about 102 of cation exchange capacity. Metson (cited by Reid) pointed out that plant responses are at <5-67. Mg saturation and unlikely at >107. saturation. The exchangeable magnesium in part determines availability of magnesium in plants. Legumes are generally higher in magnesium than grasses (95). l6 Fender (43) smmarized the factors that have been isolated as influencing the availability of dietary magnesium for the animals. 1) low pH allows soluble magnesium to be in an absorbable form, 2) Diets producing low levels of ammonia in tl'e rumm and low dietary phosphorus intake prurote magnesium absorption. Also ammonia formed frm the digestion of excessive dietary protein or high NPN diets will combine with the available magnesirm to form ammonium magnesium phosphate. At elevated pH this compound is formed reducing the availability of all three elements. 3) Pbderate intake of monovalent cations as sodium and potassium which have higher solubility than magesium campete for absorption mechanisms from the ruIen. £103 Iron may be absorbed by the roots of plants in ionic form. Availability to plants is greatest in acid soils, depending on the oxidation state (14) . Factors such as high pH and excess phosphate, bicarbonate and Ca salts can interfere with Fe uptake. The iron content in plants is a reflection of the species and soils upon which tle plants grow. The availability of iron in certain grass and legume species was studied by several authors (1, 81). Tie iron content of cultivated grasses and legumes ranges from 100 to 700 ppm. Iron deficiency in grazing cattle is rarely observed under natural conditions. Blood loss, parasites or disease can cause iron deficiency (89, 129). Miller (81) has reported the bioavailability of iron from various sources for poultry, swine and ruminants using FeSoa ‘7HZO 17 as a standard. Many factors including iron status of the animal, dietary reducing, compourds, particule size, etc. can influence the availability of iron (81). Iron is poorly absorbed for most diets. Uptake by the animal is affected by other nutrients present in the diet. High zinc intakes reduce iron absorption (30), and ma levels of phosphate, cobalt, cadmium, copper and manganese interfere with iron absorption through competition for absorption binding sites (129). Webster (138) studied the effect of cadmium during pregnancy, and reported severe fetal growth retardation. This retardation was not prevented by dietary supplement of zinc, copper or selenium. It was partially reduced by oral iron supplementation. He concluded that cadmium exerted its effect by blocking intestinal iron absorption. Selenium It is accepted that selenium is an essential element for the nutrition of ruminants. In grazing cattle, several clinical manifes- tations have been corrected by selenium supplements to the diets. Selenium-responsive diseases occur frequently. White muscle disease (WMD) is related to the geologic nature of soils parent materials. Tlere is also evidence that regional patterns of occurrence of WMD are related to regional differences in the Se con— centration of feed crops (74). The total selenium content of soils shows little relationship to tle concentrations of selenium in the plants grown on it (10). This may be due to the fact that selenium is present in tl'e soil 18 in different chemical forms that have widely varied availability to plants. The chemistry of seleniLm in soils and factors affecting availability of soil selenium to plants have been summarized (3). Many factors are interrelated with the selenium levels in soils. The principal ones are the selenium content of host rocks, the redox potential, pH and nature of the drainage waters. [Couper gt; 31 (cited by Barradas) ] . In well aerated alkaline soils selenitm tends to form selenates which are quite available to plants. In acid soils ferric ion-selenite is formed. Selenium in this form is slightly available to plants. Acid soils do not normally produce plants containing toxic concentra- tions. Relationships among the concentrations of selenium in rocks, soils and plants are surmarized as follows (3). 1) Where rocks with high content of selenium decompose to form well-drained soils in subhumid areas, the selenides are converted to selenates and organic selenium compounds. 2) Were rocks with a high content of selenium weather to form soils in humid areas, soluble complexes of ferric oxide or hydroxide and selenite ions will be formed. These soils will be slightly to strongly acid. 3) Where rocks with high content of selenium weather to form poorly drained soils and are alkaline, plants containing toxic levels of selenium are likely to be produced. The more acid the soils in an area the less tl’e likelihood of vegetation containing toxic 19 levels of selenitm. 4) Where rocks with a low content of selenium decompose to form soils mder either hrmid or dry conditions, the plant growing is likely to contain insufficient selenium to protect animals from selenium deficiency. The more humid the area tle more acid the soil, tl‘e greater the likelihood of low selenium concentra- tion in the plant. For most soils selenium values are between 0.1 and 2.0 ppm. If the total selenitm is above 2.0 ppm soils are considered seleniferous. Values up to 20.0 ppm have been reported from certain areas of Mexico (123). 1 In addition to effects of soil characteristics and pH, plant concentrations of selenirm may be affected by plant species and state of maturity. The effect of species is apparent with the variously called accumulator, or indicator plants that occur in seleniferous areas. Se concentrations up to 1400 ppm have been reported for Astragalus racemosus (129) . Accumulator species with more than 50 ppm of selenium have been found in most of the Latin American com— tries (90). The differences in Se concentration between accumulator and non-accumulator plants are great. For non—accumulator plants the Se concentrations in legume and grass hays were reported by Miltmore _e_1:_ _a__1_ (cited by Reid) to be 0.22 and 0.21 ppm respectively. Under- wood (129) pointed out that pastures and forages free from selenium- responsive diseases in animals generally contain 0.1 ppm Se or 20 more while in areas with a variable incidence of such diseases the levels are below 0.05 ppm. Biological availability of selenium in feedstuffs for chicks was studied (24). It was pointed out that selenium from plant origin was highly available, ranging from 60 to 907., but less than 252 available in animal products. Also, high availability values were observed for sodium seleiite and selenocystein. Ammer- man (I) mentioned that sulfur may interfere with the utilization of selenium. This is a result of the similar chemical structures of these elements and the fact that they form structural analog, such as selenoamino acids (seleniim is srbstituted for sulfur). Few selenium sources have been tested for selenium bioavail- ability for swine and ruminants. Basedlupon prevention of eimdative diathesis, the biological availability of selenium was 1007; in wheat, 507. in poultry by-product meal and 402 in tuna meal. Byers and Moxon (23) studied the feedlot response to supple- mental seleniim of growing and finishing beef cattle fed various protein levels. Their data indicate that the needs for selenium are greatest when protein requirements are greatest. The response to surplerental selenium was greatest for cattle fed diets that provided less than tle optimum levels of protein. Zinc Several factors influence zinc uptake by plants. Soil pH reduces availability (101). Soil deficiencies are due to reduced solubility of zinc cumpomds in the presence of calcium carbonate 21 and an alkaline pH. Zinc content in soil ranges from 10 to 300 ppm with amean of 50 ppm (14). Pl'osphorus has been reported to affect the availability of zinc when it is utilized in large applications. This has been noticed when superphosphate is used. In general, high protein feed ingredients are good sources of zinc. Values for pasture ranged betmeen 17 to 60 ppm (129) . Perm State Forage Service reported average values for different types of feeds. For example, corn as silage 31 ppm, legume forage 28 ppm and grass forage 42 ppm (86). Kalinowsld. (112) reported high levels of zinc in forages collected fran different areas in Peru. Values up to 363 ppm for native forages were found, although these levels are below the zinc concentrations producing signs of toxicity. Miller (84) has suggested the probability of problems arising even when the zinc intake is below 400 to 500 ppm. McDowell (91) reported that 24.17. of the total Latin American Forages analyzed for zinc were borderline or deficient. Underwood (129) pointed out that zinc concentration in plants falls with advancing maturity and that legumes carry higher zinc levels than grasses. Gomide (49) notes that zinc is almost immovable in plant tissue and therefore it tends to increase in old organs and in the stem. In animals the single most important factor which affects absorption is the zinc content of the diet. As dietary zinc decreases the percentage absorbed increases. Zinc absorption is highly 22 variable in ruminants going from less than 102 to more than 302 of that consumed (86). The effect of other dietary factors in zinc absorptim has been studied. High levels of cadmium reduce zinc absorption. The estimated zinc reqLu'rement for dairy cattle is 40 ppm in the diet. The toxicity threshold is estimated to range firm 500 to 1500 ppm (94). Potassium Potassium makes up 2.62 of the earth's crust. Potassium is more likely to be fouid on weathered sandy soils than on fine tex- tured soils, it is absorbed by plants in greater amounts than any other mineral with the exception of nitrogen, as K+ ion from the soil solution. Since the total amouit of potassiLm in soils is no criterion of the anoint of potassium available to plants, three arbitrarily designated categories were used by Tisdale and Nelson (126) to classify the degree of availability of poassium in soils unavailable (90-982 of total), slowly available (1-102 of total) and readily available (0.1-2.02 of total). The same authors mention that potassium content in tropical soils may be low due to leaching of soils over the years. A value of 120 ppm of available potassium is considered as adequate in soils. Potassium is a mobile element in plants. It is present in ionic form and is not associated with any particular compound. It is involved in photosynthesis and translocation of carbohydrates and as the plant matures it is found in areas of new growth. Feedstuffs derived from plants are an important source of 23 potassium in most animal diets. For gazing cattle, plant material represents the major source of potassium. In general grain and concentrates are poor sources of potassium (29, 77). Potassium levels in forages rarely go below 1.070 of dry matter. For legume forage average values are 2.5570 but this range is 0.21 to 4.937.. Grass forages are considerably lower than legumes but the ranges are of similar magnitude. Some of this variation is due to time of the year and state of maturity as well as soil fertility. Barradas (8) found potassium average values of 1.4970 dry matter for Pangola grass and 2.157. of dry matter for Guinea grass from Veracruz, Mexico. Only 157. of the entries reported by McDowell (91) in the Latin American forages were from O to 0.87. dry basis. The suggested requirement level by the National Research Comcil (94) based on the studied conducted, is 0.87. potassium for lactating cows, but it is possible that at peak of lactation a high producing cow the requirement could be 1.07. of the ration dry matter (77). It is usually considered that soils influence animal nutrition by the quantity and quality of the herbage they produce, following the usual pattern soil-plant-animal. Another important factor is eating dirt. Grazing animals ingest soil along with herbage and this ingested soil can be a major source of minerals. Some minerals are obtained by grazing livestock through the Consumption of large amounts of soil annually, up to 600 kg for cattle (55) . Soil consumption depends on the weak structure of the soil, poor drainage, high stocking rates and shortage of pasture 24 dining winter or dry seasons. Ingested soil appears to be taken in accidentally along with herbage and does not appear to be the result of depraved appetites. Herbage from grazed areas can contain up to 257. soil (Dry Matter basis). Brazilian workers reported that feces from cattle eating mud contain 957. of dry matter, 83Z ash and 647. sand. Researchers in New Zealand and the United Kingdom suggest that soil may be an important source of trace elements in the diet and perhaps the main source of cobalt. Little is known about the forms of the element and their availability and absorption in the alimentary tract. In summary, it is suggested that there is a direct soil- animal effect in animal nutrition. Mineral Interactions The biologically active forms of trace elements are probably metal chelates (9). Considering this, it was assured that many of the biological antagonisms between and among trace elements might well be the result of similarity in chemical properties. The coordina- tion chemistry brought (1 orbitals into consideration since the bulk of the essential cationic elements are found in the transition-element groups of the periodic table. Matrone (78) eiqalained the properties of coordination compounds taking into consideration, valency bound, molecular orbital, and ligand field theories. Nine essential elements fall among those classified as transition elements, which have several unique properties as paramagnetism, variable valency and 25 ability to form colored ions (20). The special properties of the transition elements have been attributed to the approximate relative energy levels of the atomic orbitals. The addition of successive electrons into the atomic orbitals is carried out in a regular manner in the order ls, 25, 2p, 35, and 3p. However, at this point the 4s orbital is filled before the 3d orbitals. The reason is that 3d lies at a higher energy level than 43 orbital (20). This situation is repeated three times in the periodic table. The number of metal-ligand bounds in a metal chelate is known as tie coordination number (CN). Matrone (78) uses the effective number as an approach to the interaction prediction. In this system a metal ion in the first transition group attains an electronic config— uration similar to the next higher inert gas. The CN is determu'ned by the number of unfilled orbitals of the metal ion. The an+ ion with 28 electrons has four more empty orbitals than krypton. Zn2+ has a Sp3 configuration or tetrahedral shape. Cupprous copper (Cu+) also has a CN of 4 and tetrahedral shape. This similarity in chemical properties may predict biological antagonisms 2+ and Cu+. Other examples are Fe3+ and an+ in which both 2 beteen Zn are (15 ions with the same CN and configuration. Cu + and Ag2+ both have d9 orbital, dsp2 configuration and CN 4. At this point the coordination number and configuration of the cations of the transition elements are highly correlated with the number of d electrons. Several other parameters are also connected in the biology of the transition elements, such as valency, 1'7 26 iso-electronicity of the valency shell and radius of the metal ion. All the minerals found to be essential do not complete their biological function in a straight way without interacting among theme selves and with other nutrients. The complexity of mineral inter- actions is well known but not completely understood, and interrela- i tionships of minerals with vitamins, proteins and energy further complicate the problem. Among mdnerals, the interactions are primarily manifested as a type of antagonism. Every element in a nutrient solution influences the others, and a balance must be maintained between all nutrients. Reid (112) snuuarized data from different authors illustrating the effect of pH on mineral absorption by plants, and the synergistic and antagonistic effects of ion interactions at the root surface. Interactions between metal ions in living systems can be classified in at least two categories (78). - Direct interaction. i.e., Substitution of a native metal ion in a biologically active coordination compound by another metal ion. Indirect interaction. Interaction of one metal ion with either a precursor in the chelate formation pathway of another metal ion or interaction of one metal ion.with a precursor in one or more steps involved in metabolic processes of another such as absorption, transport or physiological function. Suttle (122) grouped mineral interactions into six categories . . 27 according to the type of mechanism involved. Although the biologi- cal consequences of eitier type of interaction could be very similar, the mechanisms of antagonism would be different. Until now over 70 mineral interrelationships in which an additional dietary quantity of one mineral element will influence absorption or utilization of another element are known. The inter- relationship of Ca, P, Mg and K is of findamental importance. Very high percentages of Ca, P, and Mg are located in the bone and most of these elements can be mobilized for use in metabolic events of body tissue. Many of the dietary interrelationships among these minerals occur at the absorption site (61). High dietary K impaired intestinal absorption of sodium‘whereas low K increased urinary sodium excretion. High dietary K concentration enhances Mg deficiency (97) . Mg absorption was reduced by increasing dietary Ca from .347. to .687. or P from .397. to .792. Also, increasing dietary Ca decreased P absorption, but magnesium excess seemed to have the greatest bearing on reducing calcium and phosphorus absorption (99). The depressing effect of magesium upon calcium absorption may be moderated by exceeding pl'ospl’orus requirements in the diet. Phosphorus absorption also can be depressed by excessive levels of zinc, copper and . molibdenun (18) . Although calcium may interfere with phosphorus absorption, the ruminants can tolerate excessively wide calcium/ phosphorus ratios (4, 61, 71). This indicates that calcium does not have a severe effect on phosplorus absorption. High magnesium intake increased Ca loss from the body. High pl'osphorus prevented Ca loss and vitamin D affects Mg absorption fi 28 quite markedly. In summary, phsiologically calciim and magnesium are strong antagmists, but from a nutritional standpoint this antagonism is less marked. -Mol um—Sul hate Dich (1956) slowed that copper—molybdernm interaction was dependent on sulfate. He suggested a three way interaction. Sub— sequent studies showed that the sulfate could either increase or decrease copper status of ruminants and more recent studies have shown that molybdenum could do the same with copper. Since the effect of any one of these elements is dependent on both pre- vious and present dietary levels of the other two elements, it is difficult to predict the effect of dietary changes. The essential role of molybdenum in plant nutrition has been studied. Molybdenum is known to function in nitrogen fixation by soil microorganisms. Molybdenum deficient soils were subsequently recognized and significant improvements were made by appropriate molybdenum application. The principal function of molybdenum in plants is the reduction of nitrates by the molybdenum containing enzyme reductase . The absorption of molybdenum by plants is favored by low pH. However this is apparently counteracted in soils by the fact that in alkaline soils it is more available to the plant than it is in acid soils (9, 70, 86). The level of molybdenum in pastures and forages varies greatly depending on the soil conditions. Values 29 from 0.10 ppm to 100 ppm have been reported (129) . Nbst dietary forms of molybdenum, except molybdenite, are absorbed from the gastrointestinal tract, but the rates of absorption and roles of excretion may differ with species. The major biochemical role of molybdenum in animals is in tle formation and activity of xantine oxidase, a molybdenum-containing metallo protein, indispensable in the anabolic metabolism of purines to uric acid (95, 129). An explanation of the complex interrelationship of copper- molybdenum and sulphate in the open has been prOposed (60). The first interaction observed is between copper and molybdenum. High dietary Mo produces copper deficiency. The higher the copper content. of the diet the higher the level of molybdenum required to observe copper deficiency. This antagonims is due to the formation of copper- molybdenum complex at a pH range near neutrality. They proposed that copper may become unavailable through the formation of cupric molybdate that is absorbed, transported and excreted as a unit. Copper sulfide and cupric molybdate are almost insoluble and unabsorb- able. The interaction between copper and sulfate is due to the reduc- tion in copper absorption as a result of the precipitation of copper sulfide in the rumen. The mechanism of interaction between these two elements is proposed to result from the formation of hydrogen sulfide in the ruren either from inorganic sulfate or the desulfhydra- tion of sulfur amino acids. Two systems are proposed to describe molybdate and sulfur 30 interactions. One is the sulfate reduction system present in the runen and the second is in the membrane transport system. It has been shown, both E _vi_vg and g _vit_r_g that sulfate is reduced to sulfide by rmenmicroorganisme. The amomt of molybdenum is the most important variable affecting copper needs in ruminants. The effect of molybdenum on copper requirerents and tolerance is cmplex. Altkough the exact mechanisms are not understood, it is well recognized that the antagonism between copper and molybdenum is interrelated with the sulfate, sulfide and/or sulfur content of the diet (83, 86, 121, 129, 134). Amneman (1968) found that Mo and sulfate will reduce the Cu level in tissue of the cattle and sheep by reducirng the Cu uptake and increasing the rate of absorption. There is a considerable difference among animals to tie tolerance of high doses of molybdenim. Cattle have the least tolerance and sheep are next. The tolerance to high levels of molybdenum varies with the age of animal, quantity and form of inges- ted molybdenum, the inorganic sulfate content of the ration, the copper status and intake of amino acids that can be oxidized to sulfate in the body. Copper is associated with many enzyme systems of plants and animals, especially with oxidative patl'ways and respiratory pigments. In sheep, Cu is one of the few essential elements on which both deficiency and toxic excess can occur under normal grazing conditions. Barker (54) found that giving 7.7 ppm of Mo to lambs receiving high copper diets produced liver copper levels 407. lower than controls. 31 l He concluded that the addition of ammonium molybdate to the concentrate 1 diet is useful in reducing nutritional copper poisoning. Cymbaluk (34) studied the effects of molybdenum on copper metabolism using three to levels. He pointed out that the addition of Mo to the diet decreased copper absorption and retention as a consequence of excretion of dietary copper in feces, and increased excretion of absorbed copper in bile. Pblybdenum was absorbed but urinary excretion was effective in eliminating most of the Mo from the body. Spears (119) reported that increased molybdenum in the fermen- taticxn medium increased the sulfur requirerent for maximum _in_ 11133.9 ruminal cellulose digestion. Miller (83) pointed out that molybdemmm has a stimulatory effect in the cellulose-degrading microorganisms. Fisher and Prentice (45) proposed that high dietary Mo may- 1ead to the formation of a Co-Mo complex in which copper is more rapidly absorbed from the gastrointestinal tract and more slowly excreted in the urine than copper in normal diets. They also pointed out that if Cu—b’b complex is formed in the rumen or tissues of the animals it was not excreted in the urine. Industrial pollution is a potential source of molybdenum in the environrent. Ruminants are particularly sensitive to Mo toxicity (129). Molybdenosis, characterized by symptoms of copper deficiency, may occur in cattle with 4 ppm dietary Mo intake and low copper intake (60). Kincaid (70) established the minimum toxic concentration of molybdenum in drinking water of calves. He found that the *1 32 concentration of copper in liver was reduced with 50 ppm of Mo added to water, but not with l or 10 ppm. However, Cu in plasma was ele— vated with 50 ppm of Mo. Apparently uptake of plasma copper by tissue was reduced by molybdenum decreasing the bioavailability of copper. He pointed out the difficulty of detecting molybdenum induced hypo- cuprosis from plasma copper and ceruloplasmin without data on tissue copper. Ward classified Mo toxicity in four groups: - HignMo (more than 20 ppm) - Low Cuzb’b ratio (2:1 or below) I - Clapper deficient (less than 5 ppm) - Normal Cu (5-10 ppm) and Mo, both high soluble protein (20 ' to 302) This last statement probably results from high levels of sulfide produced from sulfur amino acids during ruIen fermentation. Huber e_t_ _al (59) working with lactating dairy cows found symptoms of Mo toxicity with 173 to 200 ppm in the diet. Liver, blood and milk levels of molybdenlm were increased 5 to 10 fold. Kidney and spleen concentrated Mo several times higher than any other tissues. Also the addition of .262 sulfate to rations containing 200 to 300 ppm of Mo greatly increases the severity of Mo toxicity. The same results were reported by Vanderueen (131). Cattle are apparently more susceptible than sheep to excess molybdenum and deficient copper in their diet. When the ratio of Cu to Mo in feed drops below 2:1, to poisoning can be enqnected (19). COpper is a member of the transition element with one electron in the outer shell. In addition to the metallic form, copper can exist 33 in the +1, +2, +3 valence state. The most commonly found form in solid is as the Cipric ion (Cu+2) which is absorbed by clay soils. Below a pH of 7.3 CuzJr is most abundant and above this pH CniDH+ pre- dominates (76). Copper plays a very important role in plant and animal metabo- lism. In plants it is a constituent of ascorbic acid onu'dase, the enzyme laccase and of other important proteins. In animal metabolism it is important in heloglobin formation, elastin and collagen forma- tion and melanin production. A simple copper deficiency in grazing animals as a result of subnormal concentrations of copper in forages has rarely been reported. Normal copper concentrations in plants range from 8 to 20 ppm. Six ppm is considered deficient and higl'er than 20 ppm toxic (63) . Copper deficiency is manifested by tl'e same syndrome as chronic molybdenum poisoning is identical to molybdenum deficiency. COpper poisoning is brought about by the sudden release into the blood stream of copper which has been stored in the liver. Australian work showed that gramineous species take up less COpper than many herbage plants, even on soils with high concentra- tions of available copper. The amounts of copper needed to counteract excess molybdenum is variable due to the interrelationship between copper, molybdenum, sulfate and other factors. Copper deficiencies usually occur when forage molybdenum exceeds 3 ppm and the copper level is below 5ppm (33). 7 | I 34 Sulfur-Seleninm Interactions Sulfur and selenium interact because sulfur corpounds influ- ! ence tl'e uptake of selenite by nmen microbes. Selenium may replace l tle sulfur in methionine and cystein. ! In proteins, tle covalently bound selenium is linked to either carbon or sulfur. The seleninm atom is either incorporated in place of sulfur in sulfur amino acids, or is attached to the sulfur atoms i of cysteine residnes (46). In rnminants it is probable the sulfur and seleninm nutrition is influenced by runen microbial metabolism (50). There are some implications that change in Se. Metabolism due to sulfate supple- mentation which may be due solely to changes in microbial and tissue metabolism associated with a change from a deficient to an adequate dietary sulfur supply. Also there is evidence that seleno methiqnine is one, if not the main source of seleninm ingested by ruminants and that its metabolism by the rumen bacteria differs from that of inorganic forms of selenium (108). In view of the hign affinity of heavy metals for sulfur and selenium, there are some specific biological interactions between selennm and otl‘er metals (46). There is considerable evidence that selenium protects animals from the toxic effects of certain heavy metals such as cadmium, mercury and thallium. Sulfur and selenium compete for the sane active sites of enzymes because of their similar chemical structures. These elements have similar electron configuraton, valence shell, atom size, bond energy, electron affinities and electronegativity (95). Despite 35 ttese similarities the biological prOperties of sulfur and selenium are different. Levander (50) pointed out that the metabolic differences could be explained by their oxidation states and the degree of dissociation of the SH and Se-H groups. Se compounds are reduced during metabolism while sulfur undergoes oxidation. Pope (107) describes the selenium-vitamin E-sulfur-nitrogen interrelationship. This interaction has become more important in recent years due to extensive use of fertilizers in pastures. He pointed out that tie metabolism of sulfur (S) and nitrogen (N) are very closely interrelated in ruminants. Sulfur fertilization has increased the incidence of selenium deficiency in animals (129). Zinc-Copper ~Manganese Interactions Underwood ( 129) notes the discrepancies with levels of copper may be due to the differences in zinc and iron levels in the base diet. It is known that copper competes with iron for absorption binding sites and zinc for metal-binding protein. In ruminants soluble complexes of Zn and Mn occur in the runen and lower region of the small intestine. The soluble zinc and manga— nese in the abomasum, duodenum and upper jejunum appeared to exist in ionic form (16). It appeared that much of the insoluble metal, particularly copper might be associated with microbial matter. The suggestion that over 852 of the zinc in the plant could be in the soluble form in the stomach, as a combined result of the acid envi- ronmmt and proteolitic digestion. 36 There is significant variation in the forms in which Zn, Mn, and Cu are present along the alimentary tract of swep maintained on a dried grass ration. The solubilities of the three metals in the runen were found to be extremely low. Although over 50% of the Zn, Mn, and Cu in the dried grass ration was found to be water soluble and over 9071 of tie Zn and Mn was liberated on cellu- loytic digestion of ryegrass in tke runen only 5-102 of the Zn and Mn and less than 207;. of tlre Cu were in soluble form. The large increases in the solubility of Zn and Mn on passage of the digesta into the abomasum must arise from the dissociation at low pH of tie insoluble complexes present in the rumen. Tl'e effects of Zn in young lambs was studied by Davies gt a_l (36) and their results suggest that the suckling lamb is con- siderably more susceptible to zinc toxicity than more mature animals. This must be due to greater absorbtion of dietary zinc since absorp- tion has been shown to be higher in the young of many species. Miller in 1970 snmmarized the relation between copper and zinc. Although many details remain to be established, he pointed out the important biochemical relationship existing between Zn and Cu in ruminants. For example, in liver copperand zinc bind to some of the same or similar proteins. Increasing dietary zinc can decrease liver copper in cattle. Dietary copper snpplementation also can affect metabolism and tissue concentration of other elements. Supplementation with dietary cadmium depresses copper and supplenentation with dietary iron markedly decreased liver and blood copper, ceruloplasmin and amine 37 oxidase. The effect of dieta'y protein and pl’osplorus levels on the utilization of zinc, copper and manganese on adult males has been studied. Greger (51) found interactions between phosphorus excretion and protein level. Urinary zinc excretion was significantly greater when subjects consnmed the high protein diets rather than the low protein diets. Also, the dietary treatments did not affect urinary excretion of copper, serum copper levels or the apparent absorption and retention of manganese by the subjects. Biological interactions between Se and a nrmber of other elements have been shown. These elements are arsenic, mercury, cadmium and copper (3, 1+2, 56). The presence of Se reduces the toxicity of mercury and cadmium (25, 56, 95). l The effect of copper on iron has been studied by Matrone (93). He slowed that increased levels of copper promote higher levels of hemoglobin with the sane level of iron. Several investigators con- cluced that copper does not affect assimilation of iron but does function in the conversion of inorganic iron into hemoglobin. Evi- dence of and iron—copper interaction is apparent only in hemoglobin. Iron plays a role in the synthesis of both heme and globin of hemo- globin. The primary role of copper is hamopoiesis which appears to be in the formation and development of reticulocytes rather than in the syntl‘esis of protoporphyrin and hemoglobin (93). 38 Cadmium and Zinc Almost nothing is known of interactions between cadmium and other nonessential toxic elements. But supplemental zinc appears to have a definite tendency toward reducing the toxic levels of cadmium in bovine (108) . Also that the level of Cd tolerated in the diet is much higher for cattle than for monograstric animals. Hsu (58) investigated the influence of high dietary calcium on the biochemical and morplological manifestation of lead and zinc toxicity in pigs. The results indicate that high dietary calcium (1.1%) has a protective effect against the adverse effects of Pb ' and Zn. Zinc aggravates Pb toxicity in growing pigs. Chertock _e_1_;_ a]: (26) summarized the influence of cadmium on the intestinal uptake and absorption of calcium in rats. He pointed out that cadmium inhi- bits calcium binding to calcium-binding protein. The active form of cholecalciferol is l-ZS dihydroxy cholecalciferol which regulates intestinal calcinm absorbtion. Iorentzon and Iarsson (cited by Chertock) reported that 25-hydroxy cholecalciferol-l-hydroxylase activity decreases in rats receiving cadium orally. It appears that cadmium can interfere with calcium transport by reducing the activity of this enzyme . MATERIALS ADDME'HDDS Veracruz is located along the coast of the Gulf of Mexico in the eastern part of the country between l7°08' and 22°18' north lati- tude. The area of the state of Veracruz is 72,815 sz which repre- sents 3.7% of the national territory. It is a long narrow state with the Gulf of Moo to its east and the eastern Sierra Madre to its west. Its maximum length is 800 Km and its width is from 42 Km in the northern part to 156 Km in the 4 central part. The topography is very irregular. It has the highest peak in the country, 5,747 m high, where the snow never melts, and extends to sea levels where tie average annual temperature is 30° C. This topo- graphical characteristic causes the great diversity of climates, soil types, and vegetation. Three main types of climate exist. The tropi- cal rainfall climate which covers the major part of the state is present in altitutde no higher than 900 mnmnth an annual temperature of 26.5° C and an annual rainfall of 1100 UUL The temperate rainy climate is located at altitudes over 1000 m with an annual rainfall over l500 mm and average annual temperature of 18° C. In the highest and middle mountain region the temperature in the hottest months of the year is over 18° C, falling sharply in the winter when the annual rainfall is over 2000 HHL Veracruz ranks first in beef cattle production in the country. There are 4.5 million beef cattle. Seventy-five percent of the total 39 40 animal population are cross breeds between native cattle and Zebu, Holstein or Brown Swiss. Five percent are pure breeds and the rest are native animals (Criollo). Approximately 39.4% of the total area is used as grassland from which 18.22 are native pastures and the remaining are introduced forages . location of the Sudy Arga Two regions were selected. Region I is in the southern part of the state (Isla) and Region II is in the northern Temporal part. Each region was represented by six farms. There was no mineral supplementa- tion except common salt given to the animals and there was no soil fertilization program for any of the fanms. Region I or the southern part is located 17°50' north latitude and 95°45' west longitude and at altitudes between 300 and 600 m. The average rainfall is about 1600 mmn fromn June to November. Region II (northern) is located 21°10' north latitude and 98°35' west longitude. The mean temperature is 25.5° C with an average rainfall about 1100 mm. Altlough tl'e rainy and dry seasons are generally well defined, during the sample collection period the rains were delayed by one and a half months. This resulted in a severe (brought. Collection and Preparation of Sgples‘ Sanple collections were nmade toward the end of the dry season and the beginning of the rainy season (July 15 to August 20, 1980). Region I was sampled first. Region II was sanpled after the first two rains. Iri— 41 In each farm 100 he were sanpled for soils and forages and 30 blood saxples were taken fiom cattle. Soil and forage collections were made on each farm only in the pasture where the experimental animals were grazing. , ' S_o_i_l. Areas of five hectares were sampled. A canposite sample made up of seven sub-samples was prepared. There were twenty composite samples per farm. Soil samples were taken with a stainless steel soil sampling tube at a depth of 20 cm. Each sample was placed in a marked plastic bag. later, samples were air-dried, ground, passed through a 2 mm sieve, mixed and stored in plastic bags. Ore fmrndred grams of each composite sample were transported to Michigan State University for analysis. Forages. In Region I, Pangola grass (Digitaria decunnbens) and Zacate de Llano (ngaltmn _s_pp) were the dominant species, and in Region II Star grass (Cynodon plectostaggm) and Guinea grass (Panicum madman) were sampled. The exceptions were farm 5 in Region I and farm 9 in Region II where Star grass and Pangola grass were also found. The sampling density was the sane as that for soils. Forage samples were taken with stainless steel scissors fronm the same areas as soil samples. Pangola grass sanples were cut at a height of one inch, while Zacate de Llano and Guinea were taken at heights of 2 to 3 inches. Grass composite samples (2 kg) were prepared in the field and taken to the experiment station. They were then rinsed in acidified water (0.1%. HCl). After draining, the samples were cut with scissors into pieces 1 to 2 inches long. The drying process was accomplished 42 in two steps; at the station, they were partially dried in forced- air ovens at 60° C for 7 hours to reduce moisture to a level necessary to avoid spoiling. Samples were then transported to Mexico City and dried for another 24 hours under similar conditions and the dry weight was recorded. A Wiley mill with a 2 mm stainless steel sieve was used to grind the samples. The sanples were then stored in plastic bags Mnirl-pack) and shipped to Michigan State University for analysis. Livestock. All the farms sampled were commercial beef farms. The cattle were crossbreeds of native cattle with Zebu or Brown Swiss. Thirty animals were divided as follows: 10 lactating cows in their second to fifth lactation, 10, one to three year old heifers and 10, one to ten month calves. All the animals were randomly selected at each farm and duplicate blood samples were taken by jugular venipunc- ture. One of the samples, 5 ml, was collected in heparinized tubes, kept under refrigeration, and used for hemnglobin and hemnatocrit deter- minations. The second one, 20 ml sample, was collected in silicon- coated tubes with no anticoagulant. Twenty-four hours after collection the serum was transfered to plastic vials and kept frozen until analysis. Soil Analysis A solution of _15 ammoniLm acetate, pH 7, was used for calcium, magnesium and potassinm extraction on a 1:8 soil solution ratio (8). TWO and a half grams of soil were placed into a 50 ml Erlenmeyer flask and twenty ml of extracting solution added. The sarples were shaken for five minutes at 180 excursions per minute, and filtered through #42 Whatman filter paper. Then, the soil extract was diluted by a factor of 15 with a 1500 ppm lanthanum solution (lanthanum was 43 used to avoid interferences for Ca due to Si, Al, P04, or 804). For iron, zinc and cobalt extraction, 0.1 g Pill solution was used. The soil solution ratio was 1:10. For this extraction the samples were shaken for 10 minutes. Copper extraction was made with l g HCl solution following the same procedure as for iron but they were shaken for one hour. Phosphorus was extracted from soils with Bray Pl extracting solution (0.03 _Ifl NHAF - 0.025 _I\_I_ HCl) in a 1:8 soil solution ratio for five minutes. For selenium determinations double acid digestion was used. Two mnilliliters of concentrated HNO3 and 3.0 ml concentrated HClO4 were added to 0.5 g of air dried soil and heated. A lzl soil water mixture was used for pH determina— tion. Ten grams of soil plus l0 ml of donble distilled water were placed in a 50 ml beaker, stirred for 10 minutes and read in an Orion research digital ionizer pH meter. Determination of extractable phosphorus was accomplished by the Ammonium molybdate-ascorbic acid method (Watanabe and Olseh, 1965) . A Gilford Stasar II spectrophotometer at 720 nm was utilized to determine phosphorus concentration. Calcium, K, Mg, Cu, Fe, Zn, and Co determinations were made by flare atomic absorption spectro- photometry with a Perken Elmer 5000 spectrophotometer. Calibration for procedures given by manufacturers were followed (Perkin Elmer 1976). For selenium, a variation of the fluorimetric method by Olson (102) was used. Mn Forggg Anal_13_i_s_ Double acid digestion was used for grass sanples 0.5 g of grass samples were weighted into 50 ml Erlenmeyer flasks and 3 ml of concentrated perchloric acid and 5 ml of nitric acid were added. The flasks were heated until the samples were ch:ied down to 0.5 ml, cooled and diluted with 25 ml of dionized water. Copper and zinc were determined directly frcm this dilution. A ten fold dilution was made for iron and calcinm and a one hundred fold dilution for ‘ magnesinm and potassinm using a 3000 ppm lanthanum solution. Final concentrations for these elements were determnined by flame atamic Absorption spectophotometry. A further one hundred fold dilution from the original dilution was also made for phpsphorous determina- tion. For seleniun determination, one gram of sample was digested with nitric and perchloric acid. The mineral concentrations were measured by colorimetric and fluorimetric methods respectively. Blood and Serum Analysis For hematocrit determination, blood samples in capillares were centrifuged in a Solbat centrifuge at 9500 g for 10 minutes. A card reader was used to measure the samples. Hemoglobin was determined by the cyanmethemoglobin method. Readings were obtained in a Zeizz PMZA spectrophotometer at 540 nm (35). Drabkin's diluent solution was utilized as a reagent. Serum samples were centrifuged at 1650 g for 10 minutes. Then 1.5 m1 of serum were deproteinized with a solution of 157. trichlor- acetic acid (TCA) in a dilution of 1:4, and centrifuged at 1650 g l 45 for 1.5 minutes. Copper and zinc corncentrations were measured directly fiom this dilution. Phosphorus was determined by diluting 0.5 ml of supernatant with 9.5 ml of working solution of ammonium molybdate-ascorbic acid solution. For calciLm analysis, separated 1.0 ml. of serum supernatant sample were diluted with 9.0 ml of lanthanum solution (3000 ppm). A other dilution (with a total dilution factor of 150) was made for determination of magnesium and potassium. For iron analysis a dilution of 1:2 serum - TCA 202 solu- tion ratio was mixed and reated at 90° C for 15 minutes and centri- fuged at 1650 g for 20 minutes (102). Direct readings were taken from the SLpernatant. Selenium concentrations were determined by fluorimetry according to Olson e_t a_l (1975). Calcium, magnesium, potassium, iron, copper and zinc were determined by flame atomnic absorption spectrophotometry with a Perkin Elmer 5000 spectrophotometer. Statistical Analysis Soil data were analyzed according to farm and region. Forage data were analyzed according to farm and grass type for each reg'.on since grass type was different in each region. The animal data were analyzed according to farm, region, and livestock type. For soils a nested model was used. For the forage data, a two way model was used for each region. The experimental design for the animal data was split—plot because variations among farms constituted experimental error for differences between regions, but variations among animals of the same type and farm constituted 46 experimental error for differences among livestock types. Bon— ferorni t Test was used to make specific comparisons among means. All possible correlations were established between minerals in soils, soil mirerals and soil pH, minerals in gasses, and between grass mninerals and grass dry matter. Correlations between ham- genous pairs were obtained between minerals in soils and minerals in gasses, and between minerals in soils or gasses and minerals in serum. Serum to serum correlations were also obtained for indi- vidual elements between the livestock types. For any correlation in which animal data were included only ten pairs were used. This was because of the difference in mnbers of samples for forages, soils and animals (20, 20 and 10 respectively). The SPSS system was used for computer processing of the data. RESULTS AND DISCUSSION Tle mireral concentrations in all samples are summarized and presented in Table 1 to 10. Individual farm data are presented in Table Al to A10 (Appendix). Correlation coefficients and con- fidence limits are presented in Table All to A16 (Appendix). Soil-Plantfll Calcium Relationship Extractable soil calcinm ranged fromn 157 ppm in Farm 2 up to 8059 ppm for Farm 12 with an overall figure of 3777 ppm. Values found for soils were higler than those reported by De Sousa (39) for Brasilian soils using double acid extraction solution. However, the values were within tle range reported by Blue e_t 31 (11) from soils of Eastern Panama and by Barradas (8) for soils of Veracruz, Mexico. Grass calcium concentrations ranged from 0.182 on a dry basis for Farm 1 to 0.712 for Farm 7 with an overall average of 0.41%. The calcium concentrations obtained for grasses were within the values reported for the same grasses from other tropical countries (8, 39, 62, 68, 69, 91). Calcinm concentrations in serum ranged from 5.3 mg/dl for heifers at Farm 7 to 11.6 mg/dl for calves at Farm 11 (Table A1). The lowest values were found in heifers followed by cows in Region II, but mnost of the values were within the normal range reported in the literature (4, 8, 27, 38, 93, 95, 120). De Oliveira (38) 47 48 reported serum calcium values obtained in the rainy and dry season of 10.63 and 9.30 mg/dl of blood serum, respectively of Criollo cattle fram Brazil. The calcium cuntent of soils, gasses and livestock type are shown in Table 1. Calcium values of soils from Region I were significantly lower (P<.00001) than those from Region II. Calcium content in gasses from Region I shows a significant difference (P<.0001) being lower for Pangola gass than for Llano gass. No significant differences were found between Star gass and Guinea gass in Region II. Serum calcium levels of cattle grazing in tle two regions was not different. There was a significant difference between livestock types (p<.00001). Soil calcinm correlations with other soil variables are shown in Table All. Correlation coefficients between calcium and potassium ranged frcxm .28 to .74, with a mean figure of .53. Hign interactions were found between calcium and magnesinm, copper, iron, and pH. The correlation coefficients were .76, .67, -.69, and .90, respectively. De Sousa (39) and Barradas (8) reported high positive correlation between pH and soil calcium. There was high negative correlation between soil calcium and soil iron. This agrees with Bowen (14) and explains tle interaction between iron availability in acid soils. Grass to gass calcium correlations are presented in Table A12. High correlation coefficients were found in the overall figures for grass calcium with gass phosphorus (.70), and grass calcium to grass zinc (.66). Some consistency was also found between gass calcium and grass iron. Tl'e coefficients ranged from —.18 to .66 with an ' , overall correlation of .48, being higher for a particular gass than | 49 TABLE 1. MEAN CALCIUM CONCENTRATIONS 0F SOILS, GRASSES, AND BLOOD SERA 0F GRAZING can}: FROM NORTHERX (REGION II) AND SOUTHERN (storm: I) VERACRUZ, .‘IEXICO.a Serug Ca Soil Grass Cows Heifers Calves Ca Ca ppm Z Of DM ------ mg/dl ------- Overall 3777.20 0.416 8.20 7.96 9.23 (235.50) (0.015) (0.220) (0.213) (0.215) Region I 238.60 0.223 8.00 7.70 9.30 (12.08) (0.006) (0.260) (0.240) (0.230) Region II 7315.70 0.608 8.30 8.10 9.10 (110.70) (0.015) (0.350) (0.340) (0.360) Grass 1* 713.89 0.218 8.43 8.16 9.61 (Pangola) (219.30) (0.010) (0:279) (0.241) (0.247) Grass II 252.89 0.244 6.22 7.03 9.22 (Llano) (17.44) (0.010) (0.718) (0.662) (0.276) Grass III** 6718.00 0.561 9.26 9.32 10.21 (Star) (290.10) (0.240) (0.421) (0.524) (0.528) Grass IV 7384.60 0.640 7.30 6.56 7.63 (Guinea) (159.50) (0.017) (0.493) (0.372) (0.418) Region I 227.08 0.200 8.20 8.10 9.36 Grass I (17.25) (0.006) (0.283) (0.257) (0.236) Region I 252.89 0.244 6.22 7.03 9.22 Grass II (17.44) (0.010) (0.718) (0.662) (0.276) Region II 7309.20 0.588 9.23 10.01 10.29 Grass III (150.93) (0.023) (0.476) (0.471) (0.519) Region II 7384.60 0.640 7.30 6.56 7.63 Grass IV (159.50) (0.017) (0.493) (0.372) (0.418) aNumbers in parenthesis are standard errors. *Five samples from Region II are included. **Five samples from Region I are included. 50 for regions. The relationship with dry matter was low, but con- sistent. Soil to gass calcinm correlations are given in Table A13. Correlation coefficients were high for soil calcium to grass calcium (.82) , soil calcium to gass phosphorus (.75) , soil calcium to gass zinc (.78), and soil calcium to gass iron (.65). Soil to serum correlations are presented in Table A14. Soil calcium to serum copper correlations were consistently negative for the three types of livestock. The correlations were -.29, -.20, and -.18 for cows, heifers, and calves respectively. Soil calcium to serum zinc correlation also were low, but consistent. The values are .35 for cows, .35 for leifers and .26 for calves. Grass to serum correlations are shown in Table A15. Consistency was found in gass calcium to serum magnesium with valnes of -.26 for cows, -.08 for heifers, and -.27 for calves. Grass calcium to sernm copper correlations were -.30 for cows, —.24 for I‘eifers and -.24 for calves. Grass calcium to seer zinc correlation coefficients were .29, .33, and .28 for cows, heifers and calves respectively. Serum to serum correlations are shown in Table A16. The cow to leifer calcium correlations were .32, and the cow to calf correla- tions were .26, treleifer to calves values were .36. A comparison between means (Bonferroni t Test) shows a significant difference (P<.005) between cow calcinm and calf calcium, heifer calcium and calf calcium. 51 Soil-Plant-Anigal Phognhorus RElationship Table 2 shows phosphorus concentrations of soils, grasses and blood sera. Phosphorus levels in soils do not differ signifi- cantly among regions. Differences were found in phosphorus between Pangola gass and Llano gass (P<.02) in Region I and between Star gass and Guinea gass (P<.01) in Region II. Phosphorous in Llano gass was .192 of D.M. (Dry Matter) and in Star grass .362. Serum phosphorus concentrations were 4.5, 5.0, and 5.9 mg/dl for cows, heifers and calves respectively. These values were in the normal range (>4.5 mg) indicated by Underwood (128). Highly significant differences were found among livestock types (P<.00001). Cows vs. heifers, cows vs calves and heifers vs calves were the contrasts tested using Bonferroni t test (P<.005). However, the differences were only in Rgion I (Table 2). There was a highly significant difference between regions for livestock type (P<.00001). Mean phosphornis concentrations in soils varied from .62 ppm for Farm 1 Lp to 4.74 ppm for Farm 7, (Table A2). All were below adequate levels (39). Blue SE a_1 (11) reported very low values (0.2 to 2.5 ppm) for soil in Panama. Grass phosphorus levels ranged from .152 to .422 D.M. (Table A2). The valnes were .212 for Pangola, .192 for Llano, .362 for Star, and .412 for Guinea as overall figures, ranged from deficient to adequate when compared to the 0.302 considered adequate. Jardin g; a_1 (62) reported values of .092 to .272 for forages from three different areas of Brazil. low concen— trations have been reported by Kalinowsky (64) for Peruvian grasses 52 sampled during summer and winter, with phosphorus being lower during winter. According to Christiansen (28) phosphorus is usually either deficient or not present in tle forages of Latin America. Serum phosphorus concentrations ranged from 2.05 mg/dl for cows in Farm 6 np to 8.14 mgjdl for cows in Farm 11 (Table A2). Normal values are 4.5 to 6.0 mg/dl of serum in adult cattle (27, 93, 95, 120, 128). De Oliveira (38) reported serum phosphorus con- centrations of 6.40 mg/dl in the rainy season and 5.19 mg/dl in the dry season. Tlese values were significantly different (P .01). Also Eran Brazilian cattle Sutmoller (120) reported low values (2.4 to 4.0 mg/dl) of serum inorganic phosphorus from cattle in the Amazon Valley. Values ranging frcm 1.80 to 5.70 mg/dl were reported by McDowell e_t_ a_1 (92) for cattle in Costa Rica. Soil phosphorus correlations with other soil variables are given in Table All. There was a consistent relationship between soil phosphorus and soil magnesium. The correlation coefficient ranged from .06 to .59 with an average figure of .31. Phosphorus was also positively correlated with zinc in soils. The correlations varied from .12 to .57 with an average of .32. These results agee with those given by Barradas (8) but differ fromn tle values reported by De Sousa (39). Grass to gass phosphorus correlation coefficients are presented in Table A12. Positive correlations were found between phosphorus and potassium with coefficients ranging from .31 to .45 and an average of .41. These values are similar to those reported by Barradas (8) and De Sousa (39). Consistent-positive correlations 53 TABLE 2. MEAN PHOSPHORCS CONCENTRATIONS OF SOILS, GRASSES, AND BLOOD SERA 0F GRAZING CA TLE FROM NORTHERN (REGION II) AND SOUTHERN (REGION 1) VERACRL’Z, I-EEXICO.a SerugiP Soil Grass Cows Heifers Calves P P ppm 2 of DM ------ mg/dl ------ Overall 2.60 0.297 4.50 5.00 5.90 (0.110) (0.008) (0.220) (0.200) (0.230) Region I 2.47 0.202 3.30 4.50 6.10 (0.180) (0.006) (0.180) (0.220) (0.280) Region II 2.85 0.392 5.60 5.60 5.80 (0.140) (0.008) (0.340) (0.320) (0.370) Grass I* 2.52 0.218 3.67 4.97 5.96 (Pangola) (0.249) (0.009) (0.241) (0.283) (0.321) Grass II 2.18 0.191 3.51 4.26 8.37 (Llano) (0.224) (0.009) (0.384) (0.332) (0.645) Grass III** 2.91 0.362 6.62 6.68 7.24 (Star) (0.240) (0.012) (0.436) (0.327) (0.360) Grass IV 3.00 0.416 4.22 3.97 4.08 (Guinea) (0.196) (0.011) (0.486) (0.421) (0.438) Region I 2.47 0.212 3.43 4.70 5.84 Grass I (0.268) (0.010) (0.220) (0.270) (0.310) Region I 2.18 0.191 3.51 4.26 8.37 Grass II (0.224) (0.009) (0.384) (0.332) (0.645) Region II 2.65 0.375 7.34 7.24 7.60 Grass III (0.224) (0.012) (0.031) (0.215) (0.362) Region II 3.00 0.416 4.22 3.97 4.00 Grass IV (0.196) (0.011) (0.486) (0.421) (0.438) aNumbers in parenthesis are standard errors. *Five samples from Region II are included. **Five samples from Region I are included. 54 were also found for grass phosphorus and grass copper with an average value of .48. For grass phosphorous and zinc the correlation was .63. A negative correlation was found between grass phosphorus and grass magnesiun (-.42). Soil to grass phosphorus correlations are presented in Table A13. A positive correlation coefficient was found between soil and grass phosphorus. The values ranged from .02 to .42 with average value of .20, higher values (.57) were found by Peruvian workers (69). Soil calcium to grass phosphorus was consistent going from .10 to .75. These results are supported by those reported by Brazilian workers (39). They stated that little or no'relation seems to exist between the concentraion in the plant and the available phosphorus in the soil. On the other hand, Knox e_t; _a__1_ [cited by De Oliveira (38)] reported a correlation of .6b.06 between forage phosphorus and blood phosphorus of cattle, and concluded that inorganic phosphorus in blood plasma appears to be closely related to the phosphorus intake. Table A14 presents soil to serum phosphorus correlations. The correlations are consistently low and negative (-.14, -.14, and -.19 for cows, heifers and calves respectively). Positive correlations were reported by Barradas (8) for the same comparison in a similar experiment. Grass to serum correlations are shown in Table A15. Grass to serum phosphorus correlations were .35 for cows, .21 for heifers and —.04 for calves. The same pattern was found in grass calcium to serum phosphorus correlation (.37 for cows, .14 for heifers, and 55 -.07 for claves). The same trend was found by Barradas (8). Serun to serum correlation coefficients among livestock types are presented in Table A16. The correlations were .70 for cows to heifers, .49 for cows to calves and .64 for heifers to calves. Soil-Plant-Animal Magesiun Relationship Mean magnesiun concentrations and standard errors of soils, grases and blood sera are given in Table 3. Significant differences were found between regions (P<.0003). Soil magnesium was higher in Region II. There were no significant differences among grasses within Region I and Region II. No significant differences were found in serum magnesium concentrations of cattle grazing in the two regions. livestock type by region interaction was significant (P<.02). Higher serun magnesium concentrations were found in cows and calves in the two regions. Extractable magnesium in soils ranged from 32.9 ppm at Farm 2 to 510.7 ppm for Farm 7. These values are considered high according to the values reported in the literature. For Florida soils, Breland reported values going from O to >21.2 ppm using double acid extraction. From Michigan soil, Warncke (135) mentioned 40 ppm as adequate. Barradas (8) reported values which ranged from 116 ppm to 464 ppm, from tropical soils. Magnesium concentration in grasses varied from .122 of the dry matter at Farm 10 to .312. The level in grasses was .232, .262, .162 and .162 for Pangola, Llano, Star, and Guinea grass respectively. Similar values have been reported for Pangola grass in Haiti 56 (68), Mexico (8), and Eastern Panama (11). For Guinea grass higher values have been reported by the same authors. Very low magnesium concentrations were found in 40 forage samples from Costa Rica {ladder and Davis ,.(cited by Lang 75>]. McDowell (91) reported that 47 percent of the forages sampled in Latin America were deficient in magnesium. Serum magnesium levels ranged from 1.17 mg/dl for heifers in Farm 5 up to 3.16 mg/dl (27, 95). Barradas (8) reported magnesium values (from 2.1 to 3.4 mg/dl) for the same livestock types under tropical conditions. Similar figures were reported by De Oliveira (38) for cattle frcxm Matogrosso, Brazil. Soil magnesium correlations with other soil variables are shown in Table All. High correlation coefficients were found between soil magiesiun and soil calcitm (.76) soil pH (.63), soil copper (.57), and iron (-.55). Magnesium was correlated with potassium (.40), phosphorus (.31), seleniun (.44) and zinc (.33). Similar figures have been reported by De Sousa (39) and Barradas (8). Grass to grass magnesium correlations are shown in Table A12. Magnesium was negatively correlated with all the other variables in the overall figures. Some exceptions were found for the Region II values. Negative correlations have been reported between magnesium and copper, iron, zinc and crude protein for Pangola and Guinea grass (8). Soil to grass comparisons are given in Table A13. Soil mag— nesium and grass magnesium showed a negative correlation (-.38). Grass magnesitm was negatively correlated with soil calcium (-.53) 57 TABLE. 3. MEAN MAGNESIUM CONCENTRATION OF SOILS, GRASSES, AND BLOOD SERA OF GRAZING CATTLE FROM EORTHERN (REGION II) AND SOUTHERN (REGION I) VERACRUZ , MEXICO . 56% Soil Grass Cows Heifers Calves .‘Ig Mg ppm 2 of DM ------ mg/dl ------ Overall 183.20 0.207 2.21 2.13 2.22 (9.65) (0.004) (0.052) (0.064) (0.051) Region I 65.20 0.249 2.30 2.10 2.30 (4.26) (0.007) (0.007) (0.009) (0.007) Region II 301.30 0.164 2.00 2.10 2.00 ! _ (11.00) (0.003) (0.006) (0.008) (0.006) Grass 1* 75.53 0.233 2.38 2.19 2.34 , (Pangola) (9.00) (0.009) (0.075) (0.097) (0.074) Grass II 71.14 0.261 2.15 2.55 2.85 (Llano) (5.53) (0.011) (0.249) (0.197) (0.173) Grass III** 298.30 0.169 2.36 1.98 2.33 . (Star) (18.93) (0.005) (0.816) (0.087) (0.068) Grass IV 287.78 0.167 1.78 2.04 1.74 (Guinea) (14.55) (0.005) (0.091) (0.159) (0.082) Region I 60.51 0.242 2.40 2.16 2.31 Grass I (6.64) (0.008) (0.082) (0.106) (0.080) Region I 71.14 0.261 2.15 2.55 2.85 Grass II (5.53) (0.011) (0.249) (0.197) (0.173) Region II 322.20 0.165 2.36 2.14 2.36 Grass III (17.83) (0.005) (0.081) (0.046) (0.054) Region II 287.70 0.167 1.78 2.04 1.75 Grass IV (14.55) (0.005) (0.091) (0.159) (0.082) a Numbers in parenthesis are standard errors. *Five samples from Region II are included. **Five samples from Region I are included. mag for 1% 9.2%: 58 and soil potassiLm (-.3l) . However, soil magnesium was positively correlated with grass potassium (.11) . Correlations for soil magnesium and grass potassitm were reported by Barradas (8) and De Sousa (39). Soil to serum correlations for magnesium were also negative among livestock types. The values were -.38, —.l3, and -.36 for cows, heifers and calves respectively. Soil calciLm to serum magnesium correlations were variable. The coefficients were -.22 for cows, .02 for heifers and —.25 for calves. Soil potassitm to serum magnesium correlations follow the same pattern (Table A14). Grass to serum correlations are shown in Table A15. The values were .04 for cows, .04 for heifers, and .14 for calves. Negative but consistent correlations were found for grass calcium and serum magiesiLm (—.26, -.O3, and -.27 for the three livestock types). There were highly variable correlations for grass potassium and serum magnesium. Serum to serum magnesium correlations were low but consistent among livestock types. The correlations were .23 for cows and heifers, .35 for cows and calves, and .34 for heifers and calves. Soil-Plant-Animal Potassiu_m Relationship Means and standard errors of extractable soil potassium for individual farms are presented in Table A4. The concentrations ranged from 9.97 ppm in soil from Farm 5 up to 63.56 ppm at Farm 12. Potassitm content in soils differed among regions (P<.Ol) and farms within regions (P<.00001). The values were similar to those reported 59 by others (5, 8, 11, 39). Values up to 2700 ppm are reported for limestones (14). A normal value of 120 ppm of available potassium is considered adequate in soils (126) . Mean gass potassitm levels were 2.07. of D.M. for Pangola gass, 2.12 for Llano gass, 2.47. for Star gass, and 2.497. for Guinea gass (Table 4). No differences were found among gasses in both regions, however significant differences were found among farms (P<.00001). The gass potassium values found in the present study were higher than that reported by Gomide (49) for six tropical gasses. Potassium levels in sertm ranged from 15.7 mg/100 ml to 29.0 mg/100 ml. This is considered adequate and is supported by several authors (27, 29, 44, 95). Overall means differed sig'lifi- cantly between livestock types (P<.00001). Means differed between cows and heifers (P<.005) and between heifers and calves (P<.005) . The same significant contrasts (P<.01) were reported by Barradas (8) . Soil potassium correlations with other soil variables are given in Table All. Soil potassium and soil calcitm correlation coefficients ranged from .28 to .74 with an average of .53. ,For soil potassim and soil copper correlation values were 0 to .49 with an average of .36. The potassium to iron correlation coefficients ranged from -.04 to -.64; the average was -.45. Soil potassium and soil pH correlation also were consistent. The correlations coeffi- cients ranged from .19 up to .68 with a mean of .57. For soil potassium and selenium the correlations ranged from .02 to .39 with TABLE Ova Reg Reg Gr; (P: |IIIIIIIIIIIIIZZZZ:4III______________________——_i 60 TABLE 4. MEAN POTASSIUM CONCENTRATIONS OF SOILS, GRASSES, YD BLOOD SERA OE GRAZING CATTLE FROM NORTHERN (REGION II) AND SOUTHERN (REGION I) VERACRUZ, MEXICO.a Serum K 5011 Grass Cows Heifers Calves K K ppm 35 of DM ______ :zg/dl ...... Overall 44.60 2.26 21.30 22.00 23.90 (1 54) (0.043) (0.370) (0.420) (0.460) Region I 32.40 2.11 22.70 23.00 25.90 (2.40) (0.054) (0.450) (0.610) (0.490) Region II 56.80 2.40 19.90 20.9 30.10 (1.07) (0.065) (0.530) (0.550) (1.100) Grass I * 31.24 2.03 23.00 22.70 25.20 (Pangola) (2.90) (0 076) (0.438) (0.585) (0.477) Grass II 37.98 2.10 22.02 26.78 29.20 (Llano) (4.07) (0.067) (1 640) (0.936) (0.537) creesIII¥¥ 56.10 2.40 18.10 17.55 19.90 (Star) (2.25) (0.097) (0.614) (0.569) (0.998) Grass Iv 54.00 2.498 21.32 23.71 24.10 (Guinea) (1.4 ) (0.091) (0.797) (0.710) (0.984) Region I 29.60 2.1 23.22 22.89 25.10 Grass I (2.96) (0.076) (0.470) (0.630) (0.465) Region I 37.90 2.10 22.02 26.78 29.20 Grass II (4.07) (0 067) (0.640) (0.936) (0.537) Region II 60.01 2.41 18.05 17.55 18.66 Grass II: (1.63) (0.091) (0.699) (0.453) (0.678) Region II 54.00 2.498 21.32 23.71 24.15 Grass :v (1.43) (0 091) (0.797) (0.710) (0.984) 9- . Numbers in parenthesis are standard errors. *Five samples from Region II are included. **Five samples from Region I are included. 61 a mean of .33. No definite patterns were found for soil potassium and soil zinc, soil potassirm and soil phosphorus, or soil potas— sium and soil cobalt. The depressing effect of potassium on mag— nesiun levels in soils was only found in Region II. This confirms the major exchangeable capacity of magnesitm in alkaline soils (14, 67). Grass to gass correlations are presented in Table A12. The correlation of gass potassiLm to grass magnesiim shows a negative correlation as expected in the overall figure (95). Positive correlations were found between gass potassium and gass phosphorus. The values ranged from .21 to .45 with a mean of .41. Soil to grass potassium correlations are shown in Table A13. These correlations were consistent (.20) with the exception of Grass I. There was also a negative correlation, —.31, for soil potassium and gass magnesium. Soil to serum correlation coefficients are presented in Table A14. Low but consistent correlations were found for the potassium variable, for the three livestock types. The correlation of soil potassium with serum magnesium did not show consistency. The values were .02 for cows, .15 for heifers and -.07 for calves. The same tendency was reported by Barradas (8). Negative values were found for the gass to serum potassium correlations. These were -.35 for cows, -.24 for heifers and -.24 for calves. Grass potassium was not correlated with serum magnesium significantly (Table A15) . Serum to serum correlation coefficients between livestock 62 types are shown in Table A16. The correlation of cow potassium to heifer potassium was .32, cows to calves .28 and heifers to calves .44. Soil-P1ant-Aniggl Copper Relationship Extractable soil copper ranged from 2.1 ppm in Farm 1 up to 6.61 ppm in Farm 12. The mean value of soil copper was 4.40 ppm. Values firm 2 to 100 ppm are reported by Bowen (14) for copper in soils. De Sousa (39) reported mean values of 2.1 ppm for Brazilian soils during tl'e dry season and 1.5 ppm during the wet season, showing a significant difference among means (P<.007). Barradas (8) reported 2.43 ppm for Mexican tropical soils. Grass copper values on a dry matter basis varied from 5.49 ppm to 11.53 ppm among farms values. The overall mean was 7.80 ppm. Normal copper concentrations in plant tissues range from 8 to 20 ppm and values below 6 ppm are considered deficient (8, 63, 133). Values of 2.0 ppm were reported from copper deficient areas in Peru (64). The copper concentrations found for individual gasses were within the values reported for the same gasses in different tropical areas (62, 68, 69, 90). Copper concentrations in seer ranged from .415 ug/ml in heifers to .752 ug/ml in cows. Underwood ( 129) reported the normal range of blood copper concentration from .5 to 1.5 ug/ml. Copper content of soils, gasses, and serum are shown in Table 5. Mean soil copper content was lower in Region I (3.0 ppm), (P<.Ol). Significant differences were also found in farms within regions 63 (P <. 00001) . Copper content in gasses was not different between gasses from each region. Although significant differences were detected in farms for Region II (P <. 00001), no differences were found for serum copper of cattle gazing in the two regions for the overall values. However, cows in Region I had the lower value .25 ug/ml. Soil to soil correlations are shown in Table A11. Soil copper was positively correlated with soil calcium (.67), soil potassium (.36), magnesium (.57), selenium (.27), and pH (.66). Soil copper was negatively correlated with soil iron (-.52), and cobalt (-.14). lower soil copper correlation values were reported for Mexican soils (8) for calcium, potassitm and pH interactions. Grass copper correlations with other gass variables are shown in Table A12. No well defined relationships of grass copper with other minerals were detected with the exception of iron (.54), po- tassium (.49), zinc (.71) and dry matter (.32). Barradas (8) reported positive correlations with calcium (r=. 39 to .49), seleniun (r=0 to .33) and De Sousa (39) with phosphorus (r=.39 to .49), magnesium (r=.22) and potassium (r=. 79). Soil to gass mineral correlations are shown in Table A13. ' The soil copper to gass copper correlation was .34. Soil calcium to grass copper correlation was .50 and soil copper to grass zinc correlation was .58. Inverse relationships were found between soil iron and gass copper (-.33), and soil zinc and gass copper (-.lO). Brazilian workers (39) reported negative correlations between soil calciLm and grass copper, soil copper and gass zinc, TABLE Over! Heflc (Pam; Gras (Lla , uras (Sta h UTE: (Gui Reg; Grm n 1:3 .24)” >1— >1 ab '71 9,1 ,4. 64 TABLE 5. KEAN COPPER CONCENTRATIONS 0F SOILS, GRASSES AND BLOOD SERA OF GRAZING CATTLE FROM NORTHERN (REGION IT) AND SOUTHERN (REGION I) VERACRUZ, MEXICO.a Serum Cu 5°11 Grass Cows L'eiI‘ers Calves Cu Cu , “ “ ppm EM pp: ----- ug/ml serum ----- Overall 4.40 7.80 0.51 0.54 0.53 (0.12) (0.190) (0.012) (0 015) (0.014) Region I 3.00 6.40 0.25 0.57 0.56 (0.14) (0.150) (0.020) (0.025) (0.018) Region II 5.70 9.20 ~ 0.47 0.50 0.50 (0.10) (0.300) (0.012) (0.018) (0.022) Grass I¥ 3.45 6.37 0.57 0.57 0.57 (Pangola) (0.23) (0.222) (0 020) (0.024) (0.019) Grass II 3.00 6.40 0.48 0.63 0.65 (Llano) (0.20) (0.209) (0.063) (0.066) (0.270) Grass :II** 5. 1 8.74 0.48 0.56 0.47 (Star) (0.19) (0.435) 4 (0 020) (0.034) (0.026) Grass IV 5.8 9.79 0.44 0.42 0.48 (Guinea) (0.14) (0.398) ‘(0.010) (0.017) (0.035) Region I 3.19 6.52 0.57 0.37 0.55 Grass I (0.22) (0.220) (0.022) (0.026) (0.018) Region I 3.00 6.40 0.48 0.63 0.65 Grass II (0.20) (0.209) (0.062) (0.066) (0.027) Region :I 5.59 9.02 0.49 0.58 0.47 Grass III (0.16) (0.453) (0.018) (0.030) (0.230) Region :I 5.89 9.79 0.44 0.42 0.48 Grass :7 (0.14) (0.398) (0.017) (0. 17) (0.035) Q ‘Humbers in parenthesis are standard errors. '*Five samples from Region II are included. **Five samples from Region I are included. H.4- andS¢ coppe' heife tions tivel -.23, 3212: C0113 for l seru COPP for zinc res; type tion Ma 1'81) 65 and soil pH and grass copper. Soil to sernnlmnneral correlations were negative for soil copper and serum copper. Correlations were -.24 f0r cows, -.06 for heifers, and -.18 for calves. Soil calcium to serum copper correla- tions were -.29, -.20 and -.18 for cows, heifers, and calves respec- tively. Soil copper to blood hemoglobin correlations were -.36, -.23, and -.31 in the same order. Positive correlations were found in soil iron-serum copper, soil copper-serum iron, soil copper—serum selenium and soil copper-blood hematocrit (Table A14). Grass to serum correlations are shown in Table A15. Negatively correlated grass copper and serum copper had coefficients of -.15 for cows, -.13 for heifers and -.19 for calves. Grass calcium to serum copper followed the same pattern as soil calcium to serum copper. The values were -.30 for cows, -.24 for heifers and -.24 for calves, the same tendency was found by Barradas (8). Grass zinc to serru1copper correlation coefficients were also negative. The values were —.25, —.18 and -.19 for cows, heifers and calves respectively. Serum to serum correlation coefficients between livestock types are shown in Table A16. Cow copper to heifer's copper correla- tion was .15, cows to calves .20 and heifers to calves .10. Soi 1-Plant -Animal Iron Relationship Means and standard errors f0r iron concentrations in soils, plant and animal sera are shown in Table 6. Extractable soil iron ranged from 1.95 ppm in Farm 11 to 13.86 ppm.in Farm 1. Levels of 66 20 ppm in the soil solution is considered adequate for crop produc- tion. De Sousa (39) reported values for Brazilian soils of 23123 ppm. Grass iron concentrations varied from 113.7 at Farm 5 up to 1331.9 in Farm 8. The mean was 545.1 ppm. For individual gasses the mean values were 312.8 ppm for Pangola gass, 223.4 for Llano gass, 793.0 for Star gass, and 853 for Guinea grass. The iron concentrations found in this experiment were within the range of values as those found in the same gasses in other tropical areas (8, 12, 48, 104) . The National Research Council pointed out that the ircrn content in cultivated gasses ranged from 100 to 700 ppm (95). levels in serum ranged from 1.03 ug/ml for cows in Farm 1 to 2.52 ug/ml for heifers in Farm 9. Normal values reported in tfe literature range from 1 to 2 ug/ml (27, 106). Mc Dowell (90) reported that under natural conditions iron deficiency is rarely found. The iron content of soils, gasses and livestock type are presented in Table 6. Iron values of soils from Region I were significantly higher (P<.00001) than Region II. This cornfirms the relationship between low pH and high iron concentration (14). Iron content in gasses within Region I and Region II were different. However, there were differences between farms in the iron content Of grasses (P<.00001). Marked differences were found for serum iron concentrations among livestock gazing in the two regions (P<.00001). For the overall means the contrasts that were tested using Bonferroni t test were: cows vs heifers, cows vs calves and heifers vs calves. TABLE Overs Regi< 3.0317 Gra: Gra: 67 TABLE 6. MEAN IRON CONCENTRATIONS OF SOILS, GRASSES AND BLOOD SERA OF GRAZING CATTLE FROM NORTHERN (REGION II) AND SOUTHERN (REGION I) VERACRUZ, HEKICO.a Serum Fe 3°11 65355 Cows Heifers Calves Fe re - ppm 2M ppm ----- ug/ml serum ----- Overall 7.85 545.10 1.60 1.80 1.70 (0.46) (30.58) (0.051) (0.058) (0.060) Region I 13.10 232.00 1.30 1.40 1.50 (0.60) (13.83) (0.067) (0.077) (0.082) Region I: 2.61 860.80 1.90 2.19 2.00 (0.2.) (43.70) (0 057) (0.060) (0.079) Grass 1* 12.80 312.80 . ' 1.37 1.56 1.60 (Pangola) (0.79) (35.60) (0.074) (0.81) (0.094) Grass II 12.70 223.41 1.15 1.13 1.62 (Llano) (1.00) (14.30) (0 145) (0.196) (0.203) Grass III** 3.13 793.00 1.93 2.31 2.19 (Star) ‘ (0.41) (65.60) (0.093) (0.101) (0.106) Grass :7 2.87 853.0 1.82 2.08 1.75 (Guinea) (0.38) (62.42) (0.800) (0.059) (0.099) Region I 13.50 250.80 1.32 1.48 1.60 Grass I (0.77) (23.70) (0.078) (0.078) (0.090) Region I 12.72 223.41 1.15 1.13 1.62 Grass II (1.00) (14.39) (0.145) (0.196) (0.203) Region II 2.31 856.80 2.01 2.30 2.19 Grass II: (0.17) (65.22) (0.094) (0.116) (0.11 ) Region I: 2.87 853.00 1.82 2.08 1.75 Grass IV (0.38) (62.42) (0 080) (0 059) (0.099) a‘ Jumbers in parenthesis are standard errors. *Five samples from Region II are included. **Five samples from Region I are included. (P<.00 Soil 1' potass pH -.'. for s< by th figur phosy Negat data high fora Tab] Spe< fou: ir01 1'10) 801. 68 The difference was found for cows vs heifers for the overall values (P<.005). Correlations between soil minerals are shown in Table A16. Soil iron was negatively correlated with soil calciun —.69, potassiun -.45, magnesiun -.55, copper -.52, seleniun -.35, and soil pH -.70. However, positive correlations were found in Region II for soil iron with soil calciun, magnesiim, copper and selenium. The antagcnistic effect of iron with these elements could be explained by the inverse relationship between pH and iron availability. Similar figures were reported by Barradas (8) . Grass to grass correlation coefficients are given in Table A12. Grass iron was positively correlated with grass calciLm (.48) , phosphorus (.36), copper (.54), grass zinc (.76) and drymatter (.38). Negative correlations were found in grass magnesium -.23. These data did not follow Bowen's (14) statement, since factors such as high pH, phosphates and carbonate salts interfere with iron uptake. Similar observations were reported for Meadcan grass (8) and Brazilian forages (39). Soil correlations with other grass variables are shown in Table A13. Since the content in plants is a reflection of the species, age, and soils upon which the plants grow, the correlations found in this experiment were different from what was expected. Soil iron to grass iron correlations were -.47, soil calciLm to grass iron was .65, soil copper to grass iron was .41 and soil pH to grass iron was .65. The only explainable correlation was found between soil iron and grass copper (-.33). These two elements are antagonistic. 69 A negative correlation was expected. Correlations between soil iron and serun iron were negative for the three livestock types. The values were -.45 for cows, -.43 for heifers and -.25 for calves. Soil iron to serum copper were .35 for cows, .28 for heifers and .13 for calves. Soil copper to serun iron was .40 for cows, .43 for heifers and .27 for calves. Positive responses were found for soil iron and blood hemoglobin. These were .41, .30 and .34 for cows, heifers and calves, respectively (Table A14) . Grass to serum iron correlation coefficients were .39 for cows, .30 for heifers and .23 for calves. Negative relationships were found for grass iron and serum copper and grass iron and blood hamglobin. The values were -.14, -.35‘for cows, -.06, —.34 for heifers, and —.07, -.35 for calves (Table A15). Serum to serum iron correlation coefficients among livestock types are shown in Table A16. For all the combinations, the correla- tions were positive, .56, .33 and .42. Soi lePlant~Anima1 Selenium Relationship Mean soil seleniun concentrations for individual farms are shown in Table A7. Values ranged from .071 ppm to .223 ppm. Normal values are between 0.1 and 0.2 ppm of total seleniun (27). For Region 1 Farms 4, 5 and 6 were found deficient in soil selenium. Selenium in acid soils tended to be less available. Several reports show that Mexican soils range from deficient (8, 123) to toxic (22) levels of seleniun. in 1 con) bee for 70 Seleniun concentrations in forages ranged from .054 ppm (D.M.) in Farm 4 up to .172 ppm in Farm 10. The wide variation of selenitm concentrations depended on the plant species. Levels of .1 ppm have been recommended as the annimtm desirable concentration in feedstuffs (3, 8, 46). Deficient to border line deficient values were found for Star grass and Guinea grass in Region II. Seleniun levels in serum ranged from .012 ug/ml for calves in Farm 3 up to .172 ug/ml for cows in Farm 7. Blood seleniun levels between .05 ug/ml to .20 ug/ml are considered normal. Values below this level are considered deficient (27, 31). Seleniun content of soil, grasses and livestock type are shown in Table 7. Significant differences in soil selenium were found among regions (P<.01), and farms within-regions (P<.00001). No differences were found in the selenium content in grasses for indi- vidual regions, but large differences were found among farms within regions (P<.00001). Livestock types differed significantly in their serum seleniun concentrations (P<.00001). Cows were different from calves (Bonferoni t Test P<.005). Soil selenium correlations with other soil variables are presented in Table A11. Positive correlations were found for soil selenium with soil calcium (.46) potassium (.33), magnesium (.44), copper (.27), cobalt (.19), and soil pH (.50), negative correlations were found with iron {-.35). Again soil pH helps to explain these relationships (3). Similar observations were reported by Barradas (8). Correlations between grass minerals are presented in Table A12. TABLE 7. Overall Region Region Grass 1 (Pangol Grass I (Llano: Grass I (Star) Grass (Guine Region Grass ReSior. Grass Regior CTI‘ass Regiox Grass [1) ,_. *Five **Fi\ 71 TABLE 7 MEAN SELENIUM CONCENTRATIONS or 5011s, canssrs, AND 31000 SERA or GRAZING CATTLE FROM NORTHERN (REGION II) AND SOUTHERN (REGION 1) VIRACth, HEXICO.3 Sensze S - Grass 2:1 Se Cows Heifers Calves ppm 3M ppm ----- ug/nl serum ----- 0vere11 0.133 0.102 0.078 0.065 0.058 (0.003) (0 003) (0.004) (0.003) (0.003) Region I 0.105 0.102 0.054 0.050 0.041 (0.003) (0.004) (0.003) (0.002) (0.002) Region I: 0.161 0.102 0.102 0.080 0 074 (0.005) (0.004) (0.006) (0.005) (0 004) Grass 1* 0.113 0.108 0.057 0.053 0.043 (Pangola) (0.004) (0.005) (0.004) (0.003) (0.003) Grass II 0.106 0.098 0.074 0.051 0.054 (Llano) (0.003) (0.005) (0.006) (0 005) (0 003) Grass III¥¥ 0.158 0.097 0.060 0.048 0 048 (Star) (0.010) (0.006) (0 007) (0.006) (0 006) Grass :7 0.154 0.104 0.134 0 107 0.094 (Guinea) (0.005) (0.007) (0.006) (0.002) (0 002) Region I 0 105 0.105 0 050 0.049 0.038 Grass I (0.003) (0.006) (0 003) (0.003) (0.003) Region I 0.106 0.098 0.074 0.051 0.054 Grass II (0.003) (0.005) (0.006) (0 005) (0.003) Region 11 0.164 0.096 0 059 0.047 0.048 Grass III (0.011) (0 007) (0 008) (0.007) (0.007) Region II 0.154 0.104 0.134 0.107 0.094 Grass :7 (0 005) (0.007) (0 006) (0.002) (0 002) a Numbers in -L— parenthesis are standard errors. *Five samples from Region II are included. **Five samples from Region I are included. Sela elem valu bei m 72 Seleniun was correlated with calcium (.48). For the rest of the elements correlations were very low positives, zero or low negative values. Soil to grass seleniLm correlation coefficients ranged from .04 to .24 with an overall figure of .10. No correlations were found between soil calcium and grass seleniun or grass copper (Table A13). This confirms that the total seleniun content of soils shows little relationship to the concentration of seleniim in the plants grown on it (10). Soil to serum seleniun correlations were consistent among the three livestock types (Table A14), being .43 for cows, .47 for heifers and .49 for calves. The same pattern was found for soil copper and serum seleniun relationship. ~ The values were .21, .23, and .23 for cows, heifers, and calves respectively. Table A15 shows grass-serim correlation coefficients. The values for seleniim were .08 for cows, .27 for heifers, and .23 for calves. For grass copper to serum selenium the correlation values were -.02 for cows, .10 for heifers and .03 for calves. There was a slight antagonistic effect between copper and selenium only for the cow correlations. Serum to serum correlation coefficients are presented in Table A16. High positive correlations were found among livestock types. These were .75 for cow seleniun to heifer seleniun, .80 for cow seleniun to calf, and .83 for heifer to calf seleniun. Soil-P1 Relatic are pn up to mentio soils dry se Farm 1 20 to Brazi t0 1. tratj valu 73 Soil-let-Aiimil Zinc Raationsgp' than and standard errors for zinc from individual farms are presented in Table A8. Extractable soil zinc ranged from .22 ppm up to 3.25 ppm for Farms 10 and 7 respectively. Literature reports mention 0.55 ppm of extractable soil zinc as adequate. From Brazilian soils mean values of 2.4 ppm and 1.9 ppm were reported for wet and dry seasons, respectively. Zinc grass concentrations ranged from 27.1 ppm (D.M.) in Farm 2 up to 92.5 ppm in Farm 12. Jones (63) reported values from 20 to 150 ppm. Similar values for Pangola grass were reported from Brazil (48), Mexico (8) and Haiti (68). Zinc levels in serum ranged from 0.54 ug/ml for cows in Farm 5 to 1.42 ug/ml for calves in Farm 7 (Table A8). Zinc plasma concen— trations from 0.60 to 1.40 ug/ml are considered normal in cows and values lower than 0.40 ug/ml would be indicative of deficiency. All the values found in this study were within the normal range. Mean zinc concentration and standard errors of soils, grasses and blood sera are given in Table 8. No significant differences were fomd among regions in their soil zinc content. Sigiificant differences were found in soil for farms within regions (P<.00001). No differences were found among grasses within individual regions. In Region I significant differences were found among farms (P<.002). Highly significant differences among farms were observed in Region II (P<.00001) . Differences among livestock types were sig- nificant for animal sera (PI<.0003). Bonferoni t test showed that the difference was between cows and calves (P<.005). IABI. 74 TABLE 8. MEAN ZINC CONCENTRATIONS 0F SOILS, GRASSES AND 31000 SERA 0F GRAZING CATTLE FROM NORTHERN (REGION 11) AND SOUTHERN (REGION I) VERACRUZ, MEXICO.a Serum Zn 5 11 G Zn 2:55 Cows Heifers Calves ppm 3M ppm ----- ug/ml serum ----- Overall 1.34 50.83 0.96 1.04 1.11 (0.064) (0.612) (0.029) (0.030) (0.033) Region I 1.44 31.06 0.83 0.91 0.99 (0.063) (0.836) (0.047) (0.041) (0.036) Region II 1.24 70.61 1.08 1.17 1.23 (0.011) (1.780) (0.028) (0.036) (0.053) Grass 1* 1.44 34.20 0.87 0.94 1.04 (Pangola) (0.100) (1.560) (0.046) (0.042) (0.047) Grass II 1.35 29.27 0.96 1.05 1.01 (Llano) (0.072) (1.125) (0.203) (0.098) (0.044) *1: Grass 1:: 1.33 67.70 0.96 1.05 1.10 (Star) (0.161) (2.620) (0.042) (0.071) (0.053) Grass Iv 1.21 71.71 1.11 1.20 1.28 (Guinea) (0.159) (2.590) (0.048) (0.045) (0.088) Region I 1 52 31.51 0.83 0.91 0.98 Grass 1 (0 100) (1.050) (0.048) (0.045) (0.040) Region I 1.35 29.27 0.96 1.05 1.01 Grass II (0.072) (1.120) (0 203) (0.098) (0.044) Region I: 1.32 69.7 1.03 1.13 1.10 Grass III (0.172) (2.630) (0.032) (0.068) (0.047) Region II 1.21 71.71 1.11 1.20 1.28 Grass Iv (0.159) (2.595) (0.048) (0.045) (0.088) a Jumpers in parentneSIS are standard errors. *Five samples from Region II are included. **Five samples from Region I are included. magms to .f - . 083 coef: . Regi. side This Tabl ben- iror were zin cal Tat 75 Soil to soil mineral correlations are shown in Table All. Negative correlations were found between soil zinc and calcium («.11), but correlations were variable for regions and grasses. Correlations also were variable between soil zinc and soil potassium, ranging from -.34 to .34, copper -.19 to .37, and selenium —.21 to .19. Positive correlations were found between soil zinc and soil magnesium (.12 to .74) with a mean value of .33, phosphorus (.12 to .57) with a mean of .32, iron (.05 to .24, excepting Grass III, -.08), and cobalt (.05 to .40, excepting Grass II). Correlation coefficients between soil zinc and soil pH were .14 and -.62 for .Region I and II respectively. These results were expected, con- sidering that zinc is more available in acid soils (14, 133). This result agrees with the report by Barradas (8). Correlations between minerals in grasses are presented in Table A12. Positive correlations in the overall values were found between grass zinc and grass calcium, potassium, phosphorus, copper, iron and grass dry matter, although for regions and grasses the values were variable (negative, no correlation, and positive values). Sind- 1ar observations were reported by Barradas (8) and De Sousa (39). Correlations between soil zinc and grass zinc were variable ranging from —.26 to .08. The same tendency was noticed for soil zinc and grass copper (-.17 to .31). The relationships between soil calcium with grass zinc were highly correlated, .78 for the mean and .75 for soil pH with grass zinc (Table A13). Soil zinc to serum zinc correlations are presented in Table A14. Variable correlations were found between soil zinc and sen the and 76 serum zinc (-.08 for cows, .13 for heifers and .06 for calves), while the correlations between soil calcium and serum zinc and soil copper and serum zinc were positive for the three livestock types. Grass zinc to serum zinc correlations were .26 for cows, .18 for heifers and .26 for calves. Grass copper to serum zinc and grass calcitm to serum zinc correlation coefficients were .31 and .29 for cows, .11 and .33 for heifers, and .03 and .28 for calves, respectively. Similar results were reported by Barradas (8) . Interrelationships between livestock types for their zinc content in serum were low but consistent. The correlation coeffi- cients were .24 between cows and heifers, .17 between cows and calves, and .34 between heifers and calves. Soil Cobalt Relationship Mean concentrations and standard errors for soil cobalt are presented in Table A9. The values range from .110 ppm in Farm 11 up to .287 ppm in Farm 4. Conrad (31) reported values of 0.3 ppm as adequate while less than .1 ppm are considered low. All the data found in this experiment fell within normal values. For Mexican soils mean cobalt values of .68 ppm have been reported ( 8). No significant differences were found between regions, but highly significant differences were found for farms within regions (P<.00001). None of the correlation coefficients that were obtained for soil cobalt were consistent. The mean correlation coefficient for soil cobalt with other minerals or pH was: soil calciun -.15, potassium .08, magnesium 0, phosphorus 0, copper -.l4, iron .13, selenium . observed 1 mar Me are prese 8.1 (Farm temperate from 5.8 Barradas Sc differem being hi‘ tions be vaer) , and soil found be ’1 soil pHE seleniu betWeen 5-6. F7 situati rate of law be 77 selenium .13, zinc .19, and pH -.13. Similar results have been observed by De Sousa (39) and Barradas (8). Soil pH Relationship Means and standard errors for soil pH from individual farms are presented in Table A9. The pH ranges from 5.3 (Farm 2) to 8.1 (Farm 10). Tropical soils tend to have lower pH (5 to 6) than temperate soils. The pH of Haitian soils have been reported to range fran 5.8 to 7.2 (68). For Venezuela a pH of 6.1 has been reported. Barradas (8) reported a pH of 7.0 for Mexican soils. Soil pH values are presented in Table 9. Highly significant differences (P<.00001) were found in soil pH between regions, being higher in Region II, and within regions. High positive correla- tions between soil pH and soil calcitm were found (.90 as overall value), soil pH with soil copper (.66) , soil pH with selenium (.50), and soil pH with soil magnesium (.63). Inverse correlations were found between soil pH and soil iron (-.70) and soil zinc (-.20). There were antagonistic effects between iron, zinc and soil pH, while there were synergistic effects with calcium, copper, selenitm, magnesium and soil pH. The correlation coefficients between soil pH and magnesitm for Region I was .14 with a pH of 5.6. For Reg'.on II the correlation was -.71 with a pH of 7.7. This situation can be explained caldng in consideration that the maximum rate of cation absorption is at a pH of 5 to 7 (112). Similar values have been reported for Mexican tropical soils (8). Soil pH to grass mineral correlations are shown in Table A13. TABLE 9. Overall Region 1 Region II Grass 1* (PamgOla) Grass :1 (Llano) . Grass II} (Star) Grass IV (Guinea) Region 1‘ Grass I RegiOn 1 Grass 1: ReSion I Grasg II Re Si on I Grass 1)) \ atlmber 451‘in S **FiVe 78 TABLE 9. MEAN SOIL pH, COBALT, AND GRASSES DRY MATTER FROM NORgHERN (REGION II) AND SOUTHERN (REGION I) VERACRUZ, MEXICO. Soil Soil Grass Co on pH - ppm % Overnii 6.70 0.199 27.59 (0.074) (0.001) (2.870) Region I 5.60 0.224 26.12 (0.046) (0.010) (0.332) Region II 7.7 0.175 29.05 (00%) (00m) wJe9) Grass I¥ 5.82 0.214 26.59 (Pangbla) (0.988) (0.019) (0.495) Grass II 5.72 0.235 25.44 (Llano) (0.065) (0.002) (0.501) ,Grass III ** 7.60 0.176 29.53 (Star) (0.103) (0.017) (0.568) Grass IV 7.77 0.175 28.69 (Guinea) (0.044) (0.015) (0.651) Region I 5.65 0.220 26.51 Grass I (0.067) (0.021) (0.430) Region I p 72 0.235 25.44 Grass II (0 065) (0 026) (0.501) Region II 7.80 0.179 29.58 Grass III (0.061) (0.001) (0.591) Region II 7 7 0.175 28.69 Grass IV (0.044) (0.001) (0.651) a. . . Jumbers 1n parenthesis are standard errors. *Five samples from Region II are included. **Five samples from Region I are included. High con and gras: similar and gras conclusi absorpti form of Grass D1 Relatiol 1 farms a of fres differs but si differs differe grass . Positi to .39 betwee levels by Ba: Correi some 79 High correlations were found in the overall figures for soil pH and grass calcium (.74) and soil pH and grass zinc (.75). From snnilar studies positive correlations have been found for soil pH and grass calcium and negatively correlated with iron (8). Final conclusions cannot be drawn since the effect of pH on mineral absorption may be modified by plant species and by the amounts and form of the element in the soil (112). Grass D3 Matter Relationship Means and standard errors for grass dry matter from individual farms are presented in Table A9. The dry matter ranged from 2575. of fresh weight in Farm 2 to 35.77.. in Farm 12. No significant differences were found for Pangola grass and Llano grass in Region I, but significant differences were found between farms (P<.004). No difference was found between grasses in Region II, but significant differences were found between farms (P<.00001). Correlations between grass variables are presented in Table 22. Grass dry matter was positively correlated with grass calcium (0 to 31), potassium (.06 to .39), and copper (.01 to .32). Variable responses were found between grass dry matter and phosphorus, iron, selenium and zinc levels. Correlations between some of these parameters were reported by Barradas (8) for forages from Mexico. He reported positive correlations between grass dry matter and grass calcium and negative correlations between potassium, phosphorus and zinc. Kayongo-Male e_t_ _a__1_ (65) reported correlation coefficients between ) ’nom tc0) Blood He: Hanatocr M Table 10 to 12.5 cattle 1 01d, an under S1 of 11.8 were si Differe found I copper betweeI cows , wer e 01 cows, ‘ blood and gr heifer Farm? 80 between grass dry matter and phosphorus (-.24) and potassium (—.76), from tropical forages. Blood Hemoglobin and Hamatocrit Relationship Means and standard errors for these variables are shown in Table 10. Hemoglobin values ranged from 7.9 g/dl for cows in Farm 8 to 12.5 g/dl for calves in Farm 1. Normal values in blood of beef cattle range from 9.5 to 13.5 g/dl for animals less than one year old, and 9.6 to 14.25 g/dl for mature cattle (115). From cattle under subtropical conditions Rodriguez (114) reported average values 7 of 11.8 g/dl for animals under one year of age. Hemoglobin values were significantly different among livestock types (P<.00001). Differences between cows and heifers and cows and calves were found using Bonferroni t test (P<.005), in the overall values. Correlations between blood hemoglobin and soil iron and copper are shown in Table A14. Positive correlations were found between soil iron and blood hemoglobin. The values were .41 for cows, .30 for heifers and .34 for calves. Negative correlations were observed for copper. The values were -.36, -.23 and —.31 for cows, heifers and calves respectively. Negative correlations were found between grass iron and blood hemoglobin (-.35 for cows, -.34 for heifers and —.35 for calves) and grass copper and blood hemoglobin (—.27 for cows, -.21 for heifers and —.14 for calves). . Blood hematocrit values ranged from 26.2% for heifers in Farm 11 to 38.7% in Farms 7 and 12. Normal values for beef cattle mm 10. ME C'rerall Region I Region II 4 Grass I (Pangola) Grass II (llamo) ~ - '4 crass in x (Star) CTass IV (Guinea) Region I Grass I 3eEion I Grass II 330011 II Grass III astion I: “ass IV \ 3‘ . “Va-092‘s in 1&va Sample 81 .‘IEAN HEMOGLOBIN AND HEMATOCRIT VALUES OF GRAZING CATTLE TABLE 10. FROM xogrnsmx (REGION 11) AND SOUTHERN (REGION I) VERACRUZ, ran to . , CORR 3233 cars 831T Rnar CAHT ------ g/ai - - - — — - - — - - - % - - - - - - - Overall 12.80 11.10 1. 10 31.10 31.80 34.40 (1 230) (0 174) (0 199) (0.421) (0.571) (0.548) Region I 10.80 11.80 12.00 29.70 31.40 33.80 (0.237) (0.245) (0.334) (0.561) (0.704) (0.81 ) Region 11 14.80 10.30 10 30 32.50 32.20 35.00 (2.450) (0.207) (0.160) (0.577) (0.901) (0.731) Grass I * 1 7 11. 1 11.38 29.45 30.49 32.67 (Pangola) (0 251) (0.207) (0.323) (0.592) (0.801) (0.875) Grass 1: 11.06 13.87 14.31 32.75 34.00 35.87 (Llano) (0.570) (1.04) (0.954) (0.940) (1.430) (1.060) Grass III ** 9.14 10.52 10.37 30.60 31.93 34.69 (Star) (0.236) (0.243) (0.298) (0.711) (1.360) (0.989) Grass IV 8.87 10.31 10.63 34.16 33.90 37.03 (Guinea) (0.275) (0.346) (0.248) (0.863) (1 110) (1.038) Region I 10.88 11.5 11.50 29.39 31.00 33.14 Grass I (0.272) (0.219) (0.348) (0.647) (0.825) (0.917) Region I 11.06 13.87 14.31 32.75 34.00 35.87 Grass 1: (0 570) (1,040) (0.954) (0.940) (1.430) (1 060) Region II 9.11 10.44 9.98 31.20 32.20 34.20 Grass III (0.261) (0.262) (0.223) (0.755) (1.500) (0.898) Region I: .87 10.31 10.63 34.16 33.90 37.03 Grass :7 (0,275) 0.346) (0 248) (0.863) (1.110) (1.030) a‘I’Itnzll'Jers in parenthesis are standard errors. *Five samples from Region II are included. **Five samples from Region I are included. are 27 1 (115) . hanatoc: (P<. OOOI (P<. 005 present (-.21 f the val heifers found 1 cows, 1 copper 82 are 27 to 50.57. for young animals and 31 to 497. for mature cattle (115). low values were fomd for cows from both regions. Blood hematocrit values differed siglificantly among livestock types (P<.00001). Bonferroni's t test shows significant differences (P<.005) for cows vs calves and heifers vs calves. Blood hematocrit correlations with soil iron and copper are presented in Table A14. For iron the correlations were variable (-.21 for cows, -.01 for heifers and .02 for calves). Similarly, the values were variable for soil copper (.20 for cows, .21 for heifers and 0 for calves). low but positive correlations were fomd for grass iron and blood hematocrit (.20, .07 and .05, for cows, heifers and calves), and variable correlations for grass copper and blood hematocrit (Table A15). 5 had les: mm44 growing had les cattle , calcium samples adequat grazing as a mc calves (Regio) In Reg Phosph ' that 1 the va ShOWec‘ 87.7), Sample SlM‘lARY AND CONCLUSIONS Soil calcium was low in Region I, where all the soil samples had less than.700 ppm, In Region 11 all the soil samples had.more than 4400 ppm extractable calcium. This was reflected in grasses growing in these soils. For Pangola grass 75% of the samples had less than 0.257. calcitm, which is inadequate for grazing beef cattle, while 56.47; of the Llano grass samples were below 0.257.. calcium. For the grasses growing in Region II, 11.7% of Star grass samples were inadequate, but all the samples of Guinea grass had adequate calcium levels for grazing cattle. low serum calcium concentrations were found for cattle grazing in the two regions. Taking 9.0 to 12.0 mg/dl calcium serum as a normal range, 657.. of the cows, 717. of heifers and 36.72 of the calves in Region I were deficient in calcium. In th Temporal area (Region 11) 58.77. of the cattle sampled were below the normal range. Soil phosphorus levels were low in 89.22 of the total samples. In Region I, 105 samples out of 120 (or 87.67.) had less than Sppm phosphorus. In Region II, 90.8% of the soil samples also were below that level. The comparison between the results of this sampling with the value of 0.3% phosphorus, considered adequate in grazing areas, showed that most of the forages were below 0.3%. In Region I, 87.77 (52 out of 60) of Pangola grass and 94.5 of Llano grass samples were borderline or deficient. For Region II, 26.7% of Star 83 grass an tions. had low annals animals I than 765 0.182 mm grazing reflect of the (less t out of and 53 sample in 43. Sample the se Llano coppe] REgim 84 grass and only 8.37. of Guinea grass had low phosphorus concentra- tions. Forty-seven percent of the total animal population sampled had low serum phosphorus concentrations. The percentage for animals grazing on Pangola and Llano grass was 557 and for the animals grazing on Star and Guinea grass was 39.32. Magnesium was deficient in forages from Region II. More than 762 of the Star grass and Guinea grass samples had less than 0.182 magiesium which is the minimum considered adequate for grazing cattle. Low magnesitm concentrations in forages were reflected in serum magnesiim concentrations. Thirty—one percent of the cattle grazing in Region II had low serum magnesitm values (less than 1.7 mg/dl). ‘ Copper levels lower than 0.6 ppm were found in 72.57 (174 out of 240) of the soil samples, where 91.77. were from Region I and 53.37; from Region II were deficient. About 33.72 of the forages sampled had concentrations below 6 ppm, which is accepted as border- line or deficient in plants. Deficient concentrations were found in 43.12 of the Pangola samples and in 49.17 of Guinea grass samples from Region II. These deficient levels were reflected in the serum copper concentrations. Thirty-thee percent of the animals grazing on Pangola and Llano grass in Region I were considered deficient in their serum copper levels (less than 0.5 ug/ml), and 50.57 of the animals from Region II grazing on Star and Guinea grass also were deficient. Twenty-six percent (or 62 out of 240) of the total soil samples Emmi G)d for crc forages grass 1' normal 15. 97 c Region calves is bett soil sa were wi samples than t1- selemt is cons 407. of of the levels adequat less t in thes indicat "'85 had extractable iron content lower than 20 ppm (considered deficient for crops). All of them were from Region II. Only 1.27 of the forages sampled had less than 50 ppm. All the Pangola and Guinea grass iron concentrations were within the normal range. Thirteen percent of the total serum samples were below the normal iron range (1 to 2 ug/ml). For Region I, 51.67 of the cows, 15.97 of the heifers and 16.77. of the calves had low values. For Region II, 5.07. of the cows, 0.77. of the heifers and 8.37. of the calves were below the 1 ug/ml level. It appears that Guinea grass is better able to utilize the iron available in alkaline soils. Selenium levels below 0.1 ppm were detected in 42.47 of the soil samples from Region I. All the soil samples from Region II were within normal values. For grass samples, 567 of the total samples (497, from Region I and 637 from Region II) had lower values than the 0.1 ppm considered deficient. More than 587. of the calves sampled in Region I had serum seleniun concentrations lower than 0.05 ppm, (below this level is considered deficient). Thirty-five percent of the cows, and 407 of the heifers were deficient in selenium. In Region II, 277 of the cows, 327 of the heifers and 287 of the calves were deficient. One-half of the soil samples from Region II showed low zinc levels (less than 0.5 ppm), but grasses from that region had adequate zinc concentrations. Twelve samples from Region I were less than 0.5 ppm. Only 1.67. (5 out of 360) of the cattle grazing in these areas had zinc serum concentrations lower than 0.40 ug/ml indicative of zinc deficiency. S( comditio L in 137. 0 Region I theanim nesiun, studied 86 Soil pH values found in Region II were high for tropical conditions. Only six soil samples were below pH 7. Low blood hemoglobin values (less than 9.5 g/dl) were found in 137 of cattle from Region I and in 387 of the animals from Region II. Hamatocrit values were low (less than 277) in 207 of the animals from Region I and 167. from Region II. In conclusion, deficiencies of calcium, phosphorus, mag- nesium, copper and selenium, were located in the two regions studied in the state of Veracruz. APPENDIX iii :4?! .fi Faml Farm 2 Farm 3 Farmh Farm 5 Farm 7 . ram 8 Farm 9 am‘n 87 TABLE A1,:E1m cazc:.m1 mwcsmam.2:3::s 0: 30:15, GRASSES, AND 32003 32310 F a 7:3 3132;? FOR 233172301; FARMS FROM ::omrs;ax (sums 1-6) ..:m. sourszam (FARMS 7-12)= IZRACRUZ, :L’rzz Serum Ca . Soil Grass Ca Ca Cows Heifers Calves PPm f3 6:? 2M - ______ mg/dl _______ Farm - 245 25 0 188 9.23 8.27 8.57 (1 7h) (0 01u) (0.688) (0.509) (0.h68) Farm 2 157.80 0.221 6.58 7.21 9.00 (20.9u) (0.013) (0.619) (0.628) (0.265) Tarn 3 390.50 0.23h 6.95 8.39 9.91 (3h.32) (0.021) (0.h75) (0.h15) (0.323) Farm h 195.15 0.27h 9.13 7.85 9.92 (22.93) (0.015) (0.617) (O.h80) (0.5hh) Farm 5 228.30 0.201 8.01 6.19 9.39 (37.16) (0.013) (0.598) (0.606) (1.030) Farm 6 264.85 0.219 8.2h 8.62 ’9.u2 (21,18) (0 010) (0.582) (0.737) (0.519) Farm 7 6958.25 0.71u 5.69 5.03 6.85 (269.7h) (0.029) (0.29h) (0.22h) (0.h58) F - 8 ”965.95 0.503 5.78 15.60 6.50 arm ?285.63) (0.0h1) (o 201) (0.27u) (0.275) F - 7063.68 0.5u8 9.63 9.66 11.39 arm 9 (310.30) (0.027) (O.h98) (0.885) (0.777) . -- v .119 " - 10 78 0.10 0.576 10.4h 9.05 9 :afim (223.95) (0.037) (0.76h) (0 u02) (0.906) F - 11 6 7.25 0.619 9.25 ‘ 9.96 11. 6 arm (381.56) (0.025) (0.910) (1 00) (0.058) 7 7 at ,20 9.686 9.50 9-79 9‘10, -arm -2 (22:.73) (0.013) (0.770) (0.633) (0.700) aNumbers in parenthesis are standard errors. 1'! 18.1111 Farm 2 .,J E U] \ I" . 11.2): 3L( PM ..1 88 TABLE A2. MEAN PECSPEC RES -chZJTR‘T-CIS C: SOILS, GRASSES, AND BLOOD SERA OF GRAZ; IG CATT'fi PC 3 INDIVIDUAL FARMS MC .IORTL7RN {:.ARMS 1-6) 12m SCUTEER. (FARMS 7-12) 'LRACRUZ, HEXICO.a . Serum P 5011 Grass , P P ' Cows Heifers Calves ppm 7 of BM _ _ _ _ _ I mg/dl ______ Farm 1 0.62 0.168 3.45 4.68 6.10 (0.079) (0 008) (0.208) (0.248) (0.069) Farm 2 1.705 0.154 3.60 4.11 8.04 (0.268) (0.007) (0.328) (0.281) (0.550) Far: 3 3.50 0.272 3.70 5.48 7.27 (0.364) (0.016) (0.502) (0.505) (0.504) Farm 4 3.01 0.170 5.08 6.75 7.37 (0.162) (0.010) (0.464) (0.612) (0.373) Farm 5 4.45 0.28 2.24 3.70 4.89 (0.389) (0.018) (0.273) (0.334) (0.245) Farm 6 1. 7 0.173 2.05 [2.55 3.06 3 575) (0.008) (0.175) (0.117) (0.258) Farm 7 4.74 0 422 2.61 2.47 2.72 (0.470) (0.018) (0.162) (0.095) (0 159) ‘arm 8 3.24 0.316 2.21 2.42 2.41 (0.262) (0.017) (0.056) (0.064) (0.123) Fe 2.99 0.363 6.58 7.11 6.70 rm 9 (0.239) (0.023) (0.604) (0. 467) (1.089) 7a 10 2.40 0.422 7.84 7.02 7.§l rm (0.293) (0 001) (0.258) (0.038) (0.534) Far 11 1.60 0.413 8.14 [7.76 7.98 m (0.071) (0.019) (0.347) (0.282) (0.263) 5. 7 a Farm 12 2.14 0.417 6.0“ ..05 ,7-f9q (0.101) (0.017) (0.563) (0.368) (0.43.) aNumbers in parenthesis are standard errors. .1 Farm 5 89 1431.3 {13.331110217551111 1:03:32.-. 1:10:75 0? sons, 03.48823, .1173 31003 3:32 or 0312130 CATTLE :03 :331713011 FARMS 330M 30353333 (FARMS 1-6) 21 30023223 (FARMS 7-12: 7:4. 09.02, Lance?» Serum .‘Ig Soil Grass _ng 31g . Cows Heifers Calves ppm 7 of 34 ______ mg/dl ______ ' Farm 1 67.15 0.246 2.61 2.91 2.59 (3.75) (0.012) (0.154) (0.180) (0.168) Farm 2 .90 0.315 2.22 2.62 2.85 (3.17) (0.276) (0.215) (0 173) (0 138) Farm 3 91 00 0.273 2.36 2.04 2.46 (9 22) (0.078) (0.180) (0.122) (0.127) Farm 4 ’ 65.70 0.214 2.72 1.98 2.14 (12.22) (0.009) (0.131) (0.216) (0.189) Farm 5 56.35 0.213 1.97 1.17 2.00 (7. 1) (0.008) (0.183) (0.133) (0.210) :arm 6 78.45 0.239 2.29 2.12 2.24 (16.18) (0.010) (0.175) (0.214) (0.165) Farm 7 510.72 0.177 1.49 1.44 1.56 (21.20) (0.005) (0.043) (0.081) (0.067) :arm 8 291.85 0.201 1.61 1.52/ 1.41 (20.57) (0 006) (0.072) (0.006) (0.093) Farm 9 264.10 0.149 2.36 2.29 2.53 (15.04) (0.008) (0.095) (0 098) (0.103) Farm 10 23 .50 0.125 2.25 3 16/ (2.27 (6.96) (0.008) (0.186) (0 156) .0 0.3) Farm 11 206.1 0.138 2.53 ’2.21 ’2.41 (1 .17) (0.007) (0.157) (0.075) (0.098) Farm 12 295.60 0.196 2.16 2.10 2.25~\ (16.11) (0.007) (0.094) (0.068) (0.04,; 8.Numbers in parenthesis are standard errors. ,313 A4. Farm 7 Farm 8 Farm 9 Farm 10 "-5 ”I In . ’1 90 :ABLR 14. 1323 POTASSIUM CONCENTRATIONS 0F 50115, GRASSES, 133 31003 323A 0F 0212130 CATTLE FOR 1331713011 FARMS FROM 10213333 (FARMS 1-6) 133 SOUTHERN (FARMS 7-12) VERACRUZ, Max:009 Serum K Soil Grass K K Cows Heifers Calves ppm 3 6: 3M ______ mg/dl ______ Farm 1 39.86 1.62 25.52 25.73 26.36 (4.18) (0.061) (1.124) (1.126) (0.957) Farm 2 26.45 1.64 22.07 27.02 29.09 (2.85) (0.097) (1.294) (1.165) (0.441) Farm 3 53.50 2.55 21.92 23.40 26.41 (8.92) (0.129) (0.870) (1.136) (0.731) Farm 4 52.03 2.38 23.85 24.05 25.31 (4.61) (0.094) (0.865) (0.552) (0.485) Farm 5 9.97 2.24 19.83 20.12 24-74 (1.02) (0.160) (0.881) (1.948) (2.346) Farm 6 13.12 2.24 23.51 18.04 23.65 (0.79) (0.095) (0.906) (0.665) (0.430) :arm 7 50.85 2.24 23.40 24.80 24.80 (2.27) (0.073) (1.304) (1.394) (1.080) Farm 8 49.74 2.00 22.53 22.91 28.05 (3.53) (0 060) (1.003) (1 119) (1.772) F 54.53 1.54 21.40 20.99 22.58 arm 9 (1.83) (0.081) .(0.548) (0.614) (1.699) ~ -4 Fe 10 62.45 2.49 18.03 23.43 19.5 rm (1 74) (0.122) (1.262) (1.210) (0.963) F 11 60.24 3.06 16.26 15.74 18.77 arm (2.34) (0.120) (0.840) (0.603) (1.389) . /. ~/ 3.08 17.86 18.07 18.18 farm ‘2 7523;) (;.01 ) (1.010) (0.380) (0.918) aT'Iumber in parenthesis are standard errors. \ 1313 . ~ 32132 , 121113 Farm 4 Farm 6 Farm 7 Farm 8 91 TABLE 33. MEAN COPPER COXCENSRATICHS O? SCIIS, GRASSES, AND 31003 S3.~ 0F 0212130 011113 FOR 1331713011 12105 FROM HORTEERH (FARMS 1-6) 133 50013233 (FARMS 7—12) 733401202 , 07:51:00? Serum Cu Soil Grass - cu Cu Cows Heifers Calves ppm 3M ppm ---- ug/ml serum ----- Farm 1 2.10 6.55 0 752 0.700 0.619 (0.123) (0.246) (0.047) (0.064) (0.048) Farm 2 3.11 6.09 0.496 0.623 0.680 (0.380) (0.298) (0.050) (0.056) (0.033) Farm 3 4.40 7.235 0.522 0.653 0.544 (0.448) (0.501) (0.029) (0.055) (0.029) Farm 4 2.39 6.23 0.587 0.550 0.570 (0.255) (0.431) (0.033) (0.043) (0.021) Farm 5 2.48 6.43 0.518 0.445 0.477 (0.130) (0.241) (0.051) (0.072) (0.061) Farm 6 3.93 6.04 0.470 0.480 0.484 (0.394) (0.392) (0.047) (0 046) (0.039) :arm 7 5.56 6.35 0.429 0.416 0.463 (0 201) (0.399) (0.031) (0.040) (0.054) :arm 8 4.45 11.53 0.430 0.452 0.551 (0.306) (0.663) (0.030) (0.027) (0 055) Farm 9 6.26 5.49 0.540 0.629 0.623 (0.264) (0.397) (0.016) (0.032) (0.054) Earn 10 5.76 10.36 0.474 0.415 0.454 (0.118) (0.560) (0 031) (0.021) (0.072) Farm 11 6.05 10.14 0.443 0.599 0.471 (0.180) (0.650) (0 027) (0.060) (0.052) Pa 1 ’. ‘ 11.40 0 522 0.524 0.467 93-2 (3.356) (0.331) (0.030) (0.036) . (0.022) aNumber in parenthesis are standard errors. [5315 A6. 153 u. 92 1311 A6. 321; I§EHICC§C§§TR§EICNS 0F 30:15, 0515535, 400 -1000 :13“ 0: 0R42100 01:21: 303 23017::011 FAEDS FRCM NORTHERN (FARMS 1-6) AND SOUTHERN (FARMS 7-12) 72.310302: , 7:23:00?- Serum Fe 5011 Grass Fe Fe Cows Heifers Calves ppm 3M PPm ----- ug/ml serum ----- Farm 1 13.86 450.05 1.03 1.10 1.11 (1.296) (45.39) (0.076) (0.103) (0.213) Farm 2 11.49 223.60 1.08 1.14 1.48 (0 866) (21 85) (0.124) (0.169) (0.187) Farm 3 12.21 204 10 1.04 1.17 1.45 (1.576) (23.13) (0.076) (0.130) (0.099) Farm 4 13.24 168.00 1.31 1.20 1.34 (1.296) (12.84) (0.149) (0.067) (0.119) :arm 5 14.12 113.75 1.78 2.27 2.27 (1.493) (9.29) (0.199) (0.131) (0 127) Farm 6 13.82 232 50 1.63 2.01 1.76 (2.177) (19 15) (0.177) (0.107) (0.234) :arm 7 2.72 331.50 1.72 2.17 1.91 (0.139) (24 9o) (0 125) (0.074) (0.159) Farm 8 1.50 331 95 2.03 2.24 1.92 (0.229) (79.4 ) (0.100) (0.107) (0.148) Farm 9 3.74 842.50 1.95 2.52 2.25 (0.932) (81.22) (0 107) (0.133) (0 183) :arm 10 2.12 6 4.75 1 72 1.83 1.42 (0.275) (65.91) (0 172) (0.081) (O 171) :arm Tl 1.95 752.55 2.06 2.41 2.15 \ (0.309) (87.39) (3.126) (0.192) (0.186) Farm 12 3.89 129.02 - 94 2.02, 2 36 ( .638) (7.34) (0 185) (0.166) (0.192) a 0 I Number in parenthe51s are stanaard errors. 011a 47- 4'" 31 37 71 _______ Farm 2 W .am3 H :armh 93 213;: A7. 5223 szzsxzum ccxcznTRArzcus 0F 50:15, 02.5525, 130 31000 SERA 0F GRAZING 0121;: F03 :301713011 FARMS FRCM NORTHERN (FARMS 1-6) 100 SO’THERN (FARMS 7-12) 729101302, 1512100? Serqg Se $011 Grass Se Se Cows Heifers Calves PPm 3M 993 ----- ug/ml serum ----- Farm 1 0.141 0 102 0.074 0.064 0.058 (0.002) (0.004) (0 004) (0.003) (0.002) Farm 2 0.109 0.104 0.075 0.055 0.053 (0.002) (0.006) (0.005) (0.005) (0.002) Farm 3 0.121 0.147 0.020 0.040 0.012 (0.003) (0.001) (0.005) (0.005) (0.001)' Farm 4 0.099 0.054 0.027 0.026 0.022 (0.002) (0 005) (0.003) (0.008) (0.008) Farm 5 0.088 0.101 0.062 0.057 0.050 (0.002) (0.081) (0.001) (0 001) (0.002) Farm 6 0.071 0 106 0.066 0.056 0.052 (0.001) (0.007 (0.003) (0.003) (0.002) Farm 7 0.147 0.061 0.172 0.108 0.096 (0.004) (0.005) (0.010) (0.004) (0 003) Farm 8 0.192 0.105 0.132 0.107 0.091 (0 002) (0.006) (0.003) (0.004) (0.002) Farm 9 0.223 0.137 0.128 0.102 0.103 (0 008) (0.005) (0.007) (0.010) (0.007) :arm 10 0.143 0.179 0.097 0.106 0.094 (0 003) (0.013) (0.003) (0.004) (0 005) Farm 11 0.141 0.059 0.041 0.038 0.029 (0.003) (0.003) (0.007) (0.004) (0.004) Farm 12 0.120 0.069 0.040 0 022 0.033 (0.002) (0 003) (0.005) (0.002) (0.004) aNumber in parenthesis are standard errors. 94 LEAH ZINC CCIICEITI‘PATICNS OF SOILS, GRASSES, AJID ELCCD SEPA CF GFAZIIIG CATTLE FOR IZIEI‘EDUAL 7.171235 FRCM HORTHERfl (FARMS 1-6) AED SOULHLRN (FARMS 7-12) 'EPACRUZ , IEIC". C C? Serum Zn $011 Grass . Zn Zn Cows Heifers Calves ppm 3M ppm ----- ug/ml serum ----- Farm 1 1 40 27.63 0.94 1.22 1.03 (0 078) (0.712) (0.106) (0.065) (0.090) Farm 2 1.27 27.11 0.95 1.06 0.99 (0.076) (1.139) (0.161) (0 090) (0.041) Far: 3 2 09 32.10 0.89 0.98 1.22 (0.020) (2.097) (0 031) (0.061) (0.103) :arm 4 1 28.18 1 12 0.96 1.01 (0 552) (1.952) (0 132) (0.052) (0.057) Farm 5 l 37 37.71 0.54 0.59 0.90 (0 179) (2.70) (0.040) (0.074) (0.129) Farm 6 1.46 32.62 0.59 0.67 0.84 (0.178) ’1.963) (0 064) (0.107) (0.060) Farm 7 3 25 47.67 _.04 1.31 1.42 (0.134) (2.047) (0.074) (0.099) (0 212) Farm 8 1.71 8 40 1.22 1.20 1.41 (0.154) (2.36) (0.117) (0.049) (0.119) Farm 9 0.65 57.92 1.16 1.27 1.38 (0.136) (2.98) (0.030) (0.057) (0.131) Farm 10 0.22 61.43 1.07 1.09 1.01 (0 020) (2.48) (0.036) (0.070) (0.058) Farm 11 3,27 78.74 0.94 1.06 71°O§.( (0.026) (3.04; (0.052) (O-C92> (030(4) Farm 12 _I_ 33 92 SO 7.09 1.1.0 (1.124. (0 6) (2 02) :0 050) (0.133) (0.071) E"ZIuml‘Jer in oarenthesis are standard errors. 10 95 TABLE 59' HEAR SOIL CCBALT CCNCEE1 m’“”" SOIL, ’3 -.-, GRASS CRY MALJLR FOR 1322?:“UAL FARMS FROM - A...'V.ID , :I0W..-.—:.-..:: (FAR; 1-6) .4273 500123311 (3.1.315 . 4 r. a 73.310502, 17211-0. 5011 Soil Grass Co DM 9.9111 pr. 35 Farm 1 0.267 5.84 27.10 (0.051) (0.074) (0.809) :arm 2 0 185 5.39 25.00 (0 031) (0.071) (0.741) Farm 3 0.216 6.01 27.42 (0 038) (0.085) (0.750) Farm 4 0.287 5.96 . 26.91 (0.049) (0.106) (0.614) Farm 5 0 1.2 3.43 26.31 (0 ) (0.134) (0.959) Farm 6 0.215 5.42 23.96 (0.028) (0 112) (0.777) Farm 7 0.232 7.14 25.62 (0.030) (0.080) (0.776) Farm 8 0.265 7.94 26.95 (0.046) (0.056) (0.640) F - 0.170 7.87 27.90 awn 9 (0.022) (0.063) (0.918) F 10 0.115 8.13 29.00 arm (0.012) (0.015) (0.567) r 43 7* 0.110 7.88 29.1 -a- -8 (0.011) (0.031) (0.982) 35.70 Farm 12 0.1.60 779 a _, A (0.014) (0.057) (0.723) aNumbers in oarenthesis are standard errors. n m.‘ . "we? in rn 'I| 96 :13-5 110. 5520 320001031: 100 EEMATCCRIT 711035 0F 0212130 01221: FOR :301720041 FARMS FROM XORTSFRN (FARMS 1-6) :70 50013230 (?ARMS 7-12) 73220302,:025009 0033 FFL 0123 0021 3321 CAHT —————— 3/01 - — - - - _ - - - - - - _ 5 - - — — - - - Far: 1 11 98/ 11.99 12.59 32.10 31.00 35.40 (0.450) (0.418) -(0.856) (1.110) (0 775) (2.04) Farm 2 10.91 ‘ 14.07 14.20 32.10 34.40 36.20 (0.4732) (0.885) (0.81 ) (0.862) (1.240) (0.940) Farm 3 10.72 11.96 12.32 30.90 36.40 37.40 (0.366) (0.427) (0.784) (1.000) (1.240) (1.310) Farm 4 11.24 10.49 10.28 24.80 ' 23.30 27.50 (1.000) (0.408) (0.507) (1.770) (1.660) (1.650) Farm 5 9.66 11.13 11.98 27.30 30.70 35.50 (0.381) (0.323) (0.876) (0.746) (0.955) (2.270) Farm 6 10.31 11.51 10.63 31.10 32.70 30.90 (0.379) (0.363) (0 475) (0.912). (0.883) (1.820) :arm 7 8.82 11.36 11.31 36.20 38.70 41.20_‘ (0.475) (0.716) (0.388) (1.134) (2.241) (1.236, Farm 8 7.99 09 9 92 35.00 32.30 38.30 (0.410) (0 440) (0 365) (1.422) (1.202) (1.390) Farm 9 9.20 10 30 9.70 30.80 27 10 28 7 (0.396) (0.390) (0.310) (0.987) (1 240) (1.350) farm .0 9 02 10.49 70.68 31.30 30.70 31.60 (0 389) (0.403) (0.450) (1.390) (‘ 257) (1 2L0) Farm 11 10.03 10 31 10.60 30.20 26.20 36.30 (g 337) (0.462) (0 325) (0.904) (1.940) (0 932) Farm 12 8.54 10.63 9.75 31.90 38-70 3b to (0.364) (0.4028) (0.310) (1.494) (1.422) <1 350) 8Number in parenthesis are standard errors. 6.3de32 .N:Z.J Au ZQdCdZV 22.422.23.444 22< :2 (_‘Cmn 22¢. W._. .9... o..- o no. gm. ao. u. 3. a... I my: .91. a.-. Ami-.3... 37.3.; $166... .2..3.-. 2.326.... .3.......-. $0.2... :. 3.... cc. :2- o~.- 2.- :f 3. mun: am. .. my: A..«M...~mu.v AQW...:..V AQM.-®H.lv AWO..Q:.IV Amfi..~\gH.lv Am“..a\ad.lv Acw.amu_-.v AAD..~.4.V _— 2L: 8. an. 3. mm.- mo. 2... m . .3. . my: rate“.-. Balm... Sulmmf. Sulcmf. 3.2.2... ...m..n:.-. 2.5.4.9. 37.2.-. . F... .3. ..... no. ab.- 3. 3. m... as. . my... $74.73 7...“... a.-. 26:2.-. 2.9.8.. Emlwfi-v 2.1.3.. .3..mo.-. ..........m.. if o no. .m. mo. 9... m... a... >. 3.... .2......-. 2.9.4.... Sm..m..-. Ame-:3.-. 20.9... 22.-.3.-. .219... 73.33.. as. 3;- ma. 3.: F... .3.) :m. .1. :. 1.3. 3......1. 35...... $56..-. 30.6.... Emlmfi; 2T6... 39.3.. 26...... 3. an. 2. F..- as. no. a... ..... I 3.... 2.2.3.-. 86...}.-. ............. 3.4%.-. 39.2.... 87.2..-. 86:3... .2; 6.. .2.- mm.- no. a... a... 2. 2.. mm. . 3.5 A.——..ON.IV «WC..mO.IV ADA..H.~.IV A3..M~C.V ANH..N .IV AJ—..QH.IV AJH.‘ .J..lv ROW..9~.V .4. - if 9..- om. .6.- 8.- .3.- 3. : .00... :......2... .53.... 3.5.-. 39-46.-.. :.....3.. 25...... 33.8.. .........:.. .5. 9... 3. Si 3.. as. 3. m... . H.3. .313... So... an; 29.5.. 39...... 27.3.. 21.2..-. ABLE... 39.9.. «L... 2.7 o... «.0.- 3.. cm. 0... am. 3:13;. :2... :.\.:m grim 0.....m :25 .51. 22% zen 2...... 5...... .53. 3...... 32m 3.3m 3:... 3% FE}... .._.x..$_...> .. €55: zz......=% :2... 2. 1:35.. 2.2.2.32 :2... .3 .22.. :2... m..$.....z.z 43m. ...z......._.....:_ z...§2....:. n...z...u..........; z......<._..=:_:... .2 .._._._<_ 98 .cu..cw.-. o .2....;.-. >_.- .xu..an.-. :2. .22..:m.-. >2.- Asa..ou.;. 3 .3u..:n.-. >2.- ASN..NN.IV :C. .n...~..-. ...- .ac..»a.-. =3.- as...n_.nv .2. .ac._am.-. Awe..m:.-. c~.- .mm.-.co.-. 1..- ...n. 5.... i . Sn. .3.-. 2. 86:2.-. 2.- An~.-.:m.u. :fi.l .i. .2... :n. .Nu..~m.-. m3. 22.22;. _m.| Azfl..n0.v m~. Ac...m .u. .mo..:..-. cm.- .S. .2... S. Aan..ma.. an. .3;..oH.-. >.. .8. :2.-. cu.- Am}..HO.v 2N. Ama..mm.o. om. .Nn..mo.. mm. Azd..am.lv No. .m...m... 4. AN:..ON.V ANN..mm.|v no.- .a...mm.-. .3.- .._o. .2.-. .a..- .66.. .68... o 9... .2.-. 8.- .w:.-.n~.-. :6.- ...o. .3.-. .6.- .o...am.-. m..- .H...m..-. ::.: .ne..om.-. S..- .>m.-..m.-. .32.: 90:01:93... na. 9.; maniszufiaa :. 0.13.52: 2...... ..m..m~.-v .913.-. mm. ..q..»n.-. a..- ._n..e..-. no. $8.41.. 3.. 3...... ,... n. .Cn..cm.-. :3. .2... .2.-. .0. V .a...»..- o .m;..:r.. .OM..mm.-. we. .mo.-..m.-. J . l .C .c;..»..-. m.. .»n..cu.a. .3. Asa..mu.u. us. «QC.I.WO.IV )...| V A04..PH.I ma. .om..a..- co . v V .>o..c..- m..- v Am...>~.: o A.._......-. .wm..ou.-. o .mq.-.>n.-. «m.| ~ .an...... >m. .23..Mm.-. >3.- .sx..3u.-. o .3:..ac.-. >.. .an...~.. sm. 2......6.-. QH. .no..o».-. a..- A... . ._.... . ma. Ann.. N.v ..n..a..-. no. ..n..mo.. an. .on..ac.. n“. .e...aa.-. 9.. ._...:..-. no. .nn..ac.. 2». .nn..ao.. Am. ....... :3. z». .nn..>o.-. Ma. .m...m .. nu. ..a..on.. >. :1: _. ... :.: .. v7.. .. :1: . 2;: . :5: . $0: >. 5.5. dd _ 2L: __ :LD a 3L? .. my: . my: :3. . . I . .- . .3 mm m: Ofi m3. 0:. cm. .1523. :4...“ .5... or...” 3.3m 25.x. .3... 5...... :....n .: E? £5 £5 £5 £5 z?“ 75m 24.1.22. .._< a.n<+ .nu«.=: 03:34.15". mm. 0.3 n any... :93; _S .I .4. .ua545 .on.-.o=.-., .No..om.. .um..mm.. .em..mm.-. .om..c... .o...cm.-. .cw..~m.. .....>c.-. >. 3.: 93.- o:. :5. «0. :m. g..- on. on. .. mu: ..o.-.nm.-. .a;..mo.. .mc..on.. ..:.mmH.-. .ow..o“.-. .m...om.-. .m ..hm.. .n:..ac.-. .._ :.: A..- .m. mp. a.. mo. m..- x.. m. .. my: .n...n..-. .m...=o.-. .am..m..-. .z...o..-. .aw..ac.-. .:...c..-. .ow..o... .mo..o~.. .. 3.: 5.. .w. :H. 3.. .o.- o.. mg. n;. . my: ..“..a..-. .nn..um.-. .m»..o;.. .m...¢m.-. .mo..mm.-. .on..~n.. .om..mm.-. .zm..>:.. . :.a as. .o. sm. m..- n..- no. 9 my. . my: .5..-.oa.-. .mc..om.. .ua..mm.. .ow..mm.-. .em..e... .9...m..-. .ow...~.. .....>o.-. 3a.- w:. 4». mo. . :n. z..- en. om. >. 2.: .3... m.-. .m....o.-. .....m... .n....o.. .n..-.mm.-. .u...oo.-. ..m...o.. .mr...n.. cc. «N. we. :m. a..- .N. am. no. ._. :.: m0 .n...w..-. .n...2o.-. .am..m..-. .4...c..-. .mm..ou.-. .3...o..-. .oo..w... .uo..om.. n.. n. :.. 2.. .o.- 3.. N:. n:. .. :.u ..>..a«.. .w....m.-. .om..m..-. .nw..mm.. .n..-.oo.-. .nn..mo.. .sm..a..-. ..o.. u.. 2.. >o.- u.. a:. an.- AF. 09. :4. . :.: A$A.ln~.\..lv ACO.-QH.V Ac~..nco.v RAN.-o~.lv Afl“..dc.v ANS..—M.lv A~.W..®.~.v AJM..*.C.g _».- g“. m5. 9.. c.. o..- an. a.. .. my: .>a..mc.-. .nm..c..-. .gn..>m.. .n...m..-. .H...mm.-. .oa..um.. .nm..~o.-. .mm..>m.. g_. 0.. m4. .0. ~Q.- >4. «4. >u. _ my: .cc..mn.. .m......-. .mm.-.m..-. .om..mm.. .c..-.mo.-. .nn..a... .o:..m... .nm..m... .c a an. 4:. an.- >n. _m. »n. ..:.uz. :;:m scan :xcm swan 3.3m :usn .32 :::m .:.:. 123m .:a.m .:a.m .z:m .:=:. 2:22 zsn 24.4.50. . _ _< ”4:2... «3.9.33. . _ q< 34:5: 100 .aa...=~m DETJU 2:30 .00. 9.... awnv..-.:v.~:; .: n..vJ._=.zc .4:..¢..-. .Ho..c:.-. .5:...:.. .gm...... .3...n:.-. .2n..©..-. .Ao..un.-. >. 2.: .2. ,m... am... am. 2. 2. ...._.: .. my... . a..am.-. .cfl.-.ao.-. .o:..n:.. .a>..>:.. ..v...u.-. ..n..nn.-. .>u..ax.-. ... :.: c an.- am. so. 2:. :2. u .- .. my: .ca..ar.-. .m...ua.. ..;..au.:. .o:..n:.-. .....u:.-. .:;..o..-. .:n..::.. .. 3.: .3.- :3. .o.- “n. »..- 3.. :w. . my; ..a..::.. .2:..ao.-. .:...c..-. .2:..a:.-. .>:...:.-. .52..:..-. .s...o..-. _ :.: n.. 0.. ...- 0.. n..- no. ...: . mu: .......o..-. 29...... .......:..-. 23...... ...w..«....-. 1.7.2.. .._............-. 2.. m.: 9... On. . w.. .H. ......: >. 3.... A\.%.nloaauulv Afiv~ula:~.ulv A\.A-A~.“.lv An\.na3-.v Afirkd-nr~«lu.olv A—qucnfldalw.4 AAJ:.5A\40.IV z...- ow: 3.: ..n. I..- n... 3.. .2 s... .23..a;.-. .xn..mm.. .cx..am.-._ .o:..mc.-. .....n:.-. .z:..3..-. .zm..::.. _...I :0. 2.... «N. >..: 3.. Ca . .. 3.... .n:.-..n.-. .ac..m..-. .2...a..-. .2...o..-. .22..un.-. . u..nn.-. .4...;..-. 2.- .... :.: .4... 3...: .3.: a... . 2.... 22.11... .a...:.mn.-. 2.-.... 30...... ..........:.. .........:.-. 79-..... 2.. 0...: .... a... a... :q. .-..: .. $2.. A——-aa.:dal.v A‘.\:H..~AJ.IV A\Lg.oh~m¢..lv AnmondAd.v Aacadoaauflold afiquonOA.lv Anw.s.afia~.lv »:.- no. a:.- 9.. 32.: 0.. 3.. . m.: ..:.-.an.-. .:.J.ac.. n......-. ..:..o... .r...::.-. ..:..mu.-. .....::.-. .qs. - n... .. .Jfi . g... .... - n... . ..r...>.. 2......“ :2...“ 2...... 2x3... 3......“ 3......“ :27. 2.1.7. LCD ....n .30 .3... .3.“ .3... flil‘ll"l'll‘l'|lllll"'llll' II‘. . . I .:.:=x.. ...< .2:<9 (cunL'd) ‘J'Aul.L-: Al I . 101 .9. 2.: vocaticou. no. v.3 mwmo...:m.§a .2. n..v2==.z.~ ...m........-. 3.1.2.-. 3....8. SW6... 39...... 89-6.... .23.... >. is 3.: S. 5. .2. n1: .3: ac.- .. .3: 2.1:... 2.1.2:. 28.6.... Cm..o.-.:. 3m.-...o.-. 3.12:. 2.1.3:. .2 3.. >1! ma. Q«.I N0.l 3...: Oil .M.I __ my: Aam.-O%.lv AQH.-m~fi..lv A93.Inm\~m.lv Amm....-U.w Aflfi.n@~.lv A3.~.nm~3.lv ANN...:M.IV __ 3.1. .5: .3.- ....: no. 0.. 3. .5: . .7: 2.1.3.. ...m..o..-. 3...... :56... 3.3.“... .35.... .8...-;.-. .5: .7... NH. u. .1. o... a... 03.: . wv: 23:2.-. 3.1.3.. 8.12;. 39...... .No.-.......-. 3...... «1 Z. i. . S- ..m.: .8.- >. F... 3%.... 23.2.-. 25:3.-. .83.... .3.-.....-. 2...“... 3.6:... .....- 2. Z.- ..._. ....- 3.: .9.- ... 1.5 37%.-. 816..-. 2.0-.3.-. 8.3.x. 3:3.-. 8.1.3:. 8...... .5.- ..o.- ....: m... 2. u. .5.- .. 3.. 23...... ...m..mo.:. 25.67:. 29.8.. Gulf... 2.7.3:. 39...... .m. ..N. ....: .3. 3 .74.. :4. . F... ......c.-. 39....-. . .13.. Gaza... 22.-.9... .m:.-......-. 39.2.. _.o.- 2. co. ,8. u..- o..- ....- .. my... .82.... .c~._.£.-. 2... m.-. 3N6... 2.3.3:. 39.2.. .m.........-. a... 8. .5.- o.. .3. 2.. .3- . my... .31.... ..m....o.. 22.-:1... .m.......n.. .3..ow.:. ..m......:. 3.-.... I. Z. a: o... if .3.- ..... :53: 333%. ENG." . 5%..” =.§.n 333?. .._N.:/. 31.2.]. 2......r. 9.5... 3......n .....on :...:.n 2.....7. 3...... 2...:3. .2 4:2... A1.:.:30v . H u<3<~2<$ 10 2 £3.52 03.2.2.5... ma. 3.... a..n..:...:v.§.. .5 3.3252: 5.2%.. 39:6... 23...... 31...... 3.3.... 3...... 3...... 2 E: 3.: 3.: a... o..: 2. 3.: s..- .. my... 754.... Sm.:.m.... 35.3.. 3.1.9... 3.....m. .2422... .m..........:. I. F... a... mnf m. ow. F. m... 3.: _. 2...... .a....m.... .mm..m~.. .2... 7:. 8.4.3.. .......o..:. .......c... .n...:........ ._ 5.. .9... _.o. u...- .... a... Z. .7: . m3. AAN..~.N.IV A.—n...OH.lv AN.—..QO.IV AHW..WO.V «um..O.—.lv AAM..u\.H.lV ANN.n~M.-v _1.:. 2.: NT 8. am. a... a... ..o.: . mu: ..:.-.m.«... 39:69. 376... .m...nm.. 37...... ......Z.. 3...... ....- 3.: o... 2.: 2. 3.: 9.: >. a... .21.... 58.-.... 31...... 29.8.. 30...... 8...... 3.122... a... emf MN. 0N. an. _.o. 05.: Z. 1.... A9....NO.IV ANM.aNN.V ASH.~®M.IV ADA..NH.V Afim..~..~.lv A::.-On.lv AWD.In:\u.IV nm. .6. N..- am. a... 3. 1.: : 3.3 2...... Exam.-. 2.1.8.. 3.2.3.. .8; m... 3...... 8...... N~.I >1! TN. ‘0. ~O.I «mil An.l _ 5.... 2.1-.7... .mm.:.$.. 3.1.2.. .mm..mo.. ..........m.. C... .1. 3757. 2.: 3.: 2. N1 3. no: 9...: .. mu... 33.0... Calms.-. 3.2.2.. 3.1.9.. ...m......:. 29.2... 39.6.... c.. .1. 8. «m. n... no. ....: . my. 3.8.. 39.22... 3.4.9... 29.9... in... 33.6... .o...:....... 2.: cm.- 3. on. 3. ms.- o...: :59... 2:37. :35 3:1“ :55 23:7. :....Cr. .12.... 5...... :2...» :5... 3.2.... an...“ 3.x...r. n1...]. A13.—30V . — 3.2.22... .4523... .N......S.u> A. 23.33.. 222.353.” 22< F A.. 23.3.4—u—v 2:223:32 23:: v—3.<..—.2: 22¢ W.—<=HZHZ Mun/NZ... .5232. ad: 22.43;.3: .A...Z.1.——U—...~. 33.4 23.~._.<._33v:~u~ :N—< .d..:<... 103 A3....OO.IV ca. A213; 2.. AC“..$—.IV Z. Acn..na.uv ma. Aoz..ac.-v Ca. A.” ..€—llv >3. 7:; ..a_...v _q. 5.;1; 3. Asa..mm.uv >3.- .m:..a:.uv 03.- A:“..mo.:. a“. 3:5; as. AN ..fi.:.lv $95.1; mm: A2. 51; ¢~.- Ase.-.~n.-v a..- Awe..m:.nv :m.u Ano..::.uv x? 21.3.; . :.- Accola “-.lv Aux..ww.uv o Ano.n.:m.uv Hm.u Aao.u.mm.uv 4m..l 4.. Ada..wz.uv mm.u Awm.. m.uv o Aou..wm.uv oo.- Ace.-. m.-v Adm..o~.lv no. AHA.._:.-V »~.x 31.3.; :M.l Ame..:;.lv mm.- A3207; no. Aaz..m:.uv J 5 Aafi..o:.'v 34”.! mm 3m I .:.I .m....a.-. Ac>..um.v Aam..co.-v An>..c:.v Ape.».m:.-v __. >0. P.. mo. n.- 2:... H.-. 31.2.; ASLS.-. :o.-.~m.; 21.9.; as. _a. ma.. n~.- Ho. A“...a~.-v .«d..aa.-. Rom.-.o:.-. Ana.-.n;.-v .:fi.-.ua.-v a 93.- pw.x am.- om.- .nz..a_.v Ac»..nm.v Awe..mm.lv Ran..o:.v Awa..nu.v .m. as. -.- 9:. an. 1.55 555 "£55 "£55 .555 1;<:: :u_ :g: as. xm. >q. ._ mu: Axe..mm.v A;:..o~.-v Azm..;o.v Ad. :;2 2:. ya. a“. __ my: Ad...~:.lv Ana..afi.-v Amm._ a_1v __ 5;: >&.. AH. no. _ my: Anx..mm.:. Am:..~o.v an“..o_.uv _ :;u do. gm. m_. _ 2;; “MM..QH.IV Amz.n%0.lv AC:.n©3.lv mo. mm. Fa. >q 3“: Aaw..un.v Anm.. m.-v AH:..>3.-V on. no.1 u. ___ :g: AHA..~:.-V Acm..o~.-v Amn.. a.-. »~.- AH. no. __ :;: Rog..mo.w An~.:.nm.nv Ans..:;.-. .u. >m.| ~m.- _ :;c AO.—._fi;.v AO:.aOH.V A~.~..3—.V nfi. :m. a“. __ my: Ac“..cfi.uv Azm..mo.-v Aqfi..n#.-. n~.u :A. Mo. _ my: A;>..uo.v Ana.-.m;.lv Awn..:_., a». 3;.. an. A_:;a>: chc mz<=c z A. 22.3me 223:...32n az< mm4 2: 2.1.8.; 29:8; Awning-V $6.61; 29.2; 39.2; 24.8; 3. Am. r..- S. mm. on. .u. EH Eu 2.1.3.; 30.2; 2.4.3.; 2.4.. :7; 25:9: ASL-d; ABLE-V a. m... 23,- S.- R. a... .:.- : .2: 3.42.9.-. Zulmnfv Suzi-V Rum-£9; 7.9.2; ARLS; 2.3.9.; 8. Si co. 3.. afl. 2. 3.- _ E: 80.3; 39.3; 25,-6.1; 21.2.; 25...}; :.....8. 72.4.1; a. o... «.m.- mo- 3. 3. us. I 23: 3.1.3.; 25:5; 3.2.5.; 2:64.; 8.565; $9.2; 3:18.; .5. mm. no. m.- an. 5. 3.- A we: A3__..>«.v AQJ..M~N-v A_C..~N.lv AHO..ANN.IV A~._...::.v AO._..$N. Ana..-:m..lu an. N“. «7.- 8. a... 1.. n7.- :Fr-S: 3.5.2 :N. a... mo. .8. 3. ..m.- an. o if I my: 8:28.; ARme-V 39...... 39.9... ARLaT; 29.3.. 3......of. .: 3.: om. no. an. 2.- 3. am. 3... 2 we. 8n...o.-. 3m..am.-. 31...“... 2551-. 2.7.9.-. 37...... 3557-. I E: .5. a 27 mo. .1. 2. ..o.- . m2. AHA...—C.v ANN..MM.IV AWH..nw-.lv Amm..wm..lv AH“..®F.IV Amfl..mvfl.lv Amn..-m.lv — «7:. on. mof ..o.- N... no. as. :f . mu: 33.3... 34.8.-. 2:3.-. Ami-3m.-. 39.2.. Sm..wN.-. Sid... no. .6. 3. :m.- . on. o 2.- i 5.. 20:6. .359; 3:2.-. 39%.-. an... .-..-. 2.1.8.. Snug.-. 9? ..o{ 2. £- mcf _F. 2. .: 2.5 89.8.; .318.-. 31.3.; 3W6... Emlm... Sniff. .mN..Om.-. ..c. o .8.- mo. 2.. 3. ..o.- .. 5...: 3.1.8.; 314?; 37.3.; 30:91; 2.0-.2... 2.1.22; Ana-xi... ..-.. .3.- um- S.- ..m.- 3. mm...- . 2: 2.3.8.. 39.3.; 2:18.. 2.1-.3.-. 8.1.2... 2.1.3.. 3.1.3.-. a... .6. .3. N.- u. a. .5. : my: .213. 31...... 2.9.3.; 31.9.. Cal... Cali. 31:3; 3. .3.- 2.- no. 2. 2. ..:.- . .5. 2.9.3.... .29-J”... Asa-.2.-. 29.x“.-. 2.723.; 39.5.; Asa-:6; 5... ON.-. :..- 0.71 am.- o~.-. N:.I 33.2.3. .555 2:55 :N.. .2. ..n..::.. on. :xfi.rn.. Azm..OH.IV ma. .w...mm.-. ...- .ma..o:.-. m..- 80.2.. mm. A:m..0~.lv NH. 39.... mm. .uo..om.. m... AN.—..N~.Iv 3.. 3....2... :N. .n....... Aow..wm.-. 3 :m..mN.-v :0. .m:..m~.-. ca. .mm..cm.-. No... A m..om.-. o . $3.3: uo:ch=3.-. mm. 0.3 a.nv.....:u..:_. _J $395.2: .cu..m..-. .3.- ..n..mo.. .fi. A09..~fi.v an. .aw..mM.-. .:m..~m.-. .2..-.on.-. yo.- >“.- .. my: 3n..9-..-. 30.5%-. :. .2: “c. an.- .. my: Aan..m:.-v Anglanfv .. 3.... N... m...- . 3.... A_.m..o~.x. 2.3....fl.lv .3... .4. a..l .mv: .:N...m.-. .z..-.on.-. 9.. cm. >o.- »:.- >..- >. :.: .22...n.. ..~..»m.-. .co..am. .ow..mm.-. .nm..oc.-. .nm..mN.-. .Am.. n.-. .z. n..- a.. mo. ... mo.- .o.- ... :.: .ocw.n>.. .m...w;.-. .u:..m..-. .m;..w..-. ..m..mo.. .an._mH.-. .m...afi.-. on a. - o.. w.. ... u.. 3..-. .. =.: .mu..mm.-. ..w..mo.. .....wm.-. .nm..mm.-. .oo..mn.. .nn..mo.-. .nn..c .-. 0 mm mo.- «0... ..o. n... n.. . a... .o»..mn.. .om..om.-. .a...m... .m~..~..-. .a...~..-. .p...a..-. .a:..:... so ~o - mm o o no.- an.- .. my: 5.x... .34.... 3.2%.... .8..2.-. 5;?- :.u..:.. 2.9.57. .. n. am we. an. ... n~.- . my: .ay.hma.. .n...m..-. .oc..m;.. .>m...... .no..an.. .n......-. .uz...u.. _. me ..n. n. ma. .3. an. 29.9.5 :x<=: unu. Aao..>x.. .3. 3.1.2..-. :0.- .>:...:.-. 2..- 3.....:.. v- .a. AN..nfla-Jov >z. .gm.....-. as.- .....A..-. :2. .2...a;.-. 2:.- .m...>..-. 3 .aa..cx.. 3: . FDI’IIIIII' I- Aomonmwnolv co.- ..m.. u.-. :3 . .m:..m..-. 0.. .o...:..-. .q.- .cm..u..-. co.- NC. AN-afinn‘uclv .m:..m..-. o.. .....n..-. u..- ..... a.-. 23.! Aa—..A¢~.v A.:..>o. .do a. Aa—.oad% o 2:.- .n:.-..n. 23.: Aflag. an... 2.....- .u:...: 3... ..3..... n..- .32..n.. I v -. I V l v I V -. 1.32:. zit... . It..." III, li-'ll'l CI.) - -l Iii-J Am:.. —O.V .fi» .an..:... 3.. .a...c:.-. :q.l .o:..a:.-v OH. ..:...:.. on. ..a..n... n.. A~\.~.a3._.lv 2..- .mm..::.-. n.. Awo—cam —.V . 3.. .3...c:.-v .a..s.. .ac..nn 5. \d - .a»...: 2:. Tu... ...... :u. Afi—.a..~w . .... . .30..n an. 3... :1 a». ANS. «FA... 3... Ans..nw N.. a A .2»..>: 3... AAJ~ o n_~.4- “9. n:. no. >2.- ..c..ma.-. .s...a..-. .uz..nn.. .s»..mo .c.- »:.- 2.. .;q :25... 3.5.... 2:5... 555 an. .oo.-.:n.-. .n:..:2.-. :fi . I nu. 3. Afio—aa‘oD-Iv An~dan .q-dc'v a.. .3. .. AdgnanHO-IV Af.~.nm13.v u. an. . Adflcu «Jul-v AA.v.fi.aA\‘Ad.v :s.- .2. .. .nn..»o.-. .t...;3.. n.. :.. . nufi.a-n-IV A-~.a\x.~.v 3 2.. . Mam<.:. .é.<.:. .J..—. 3.3 m. . .3. 3.. .m. 3.. 3.. n3. .. mu: .3...mm.-3 .33..m3.-3 .3...3:.-3 .33..m:.- .3...33.-3 .3:..33.-3 ..3...u.-3 .._ :33 >3. 3..- n..- 3..- 3.. 33. 3 .3 33: .3...3..-3 .mm...m.-3 .3...3..-3 .za..33. .;3..3;.-3 .3”..3..-3 .33..3..-3 _. 3.: m . 33.- 33. 3». :s.- 3.. .3..- . 3:; .3......-3 .3:...3.3 .....3..-3 .3n..n..3 ..n..>..-3 .w...»..-3 .33..3n.-3 . 3.3 3.. cm. :0. .3. 33. >3. 3 . mu: .3:..33.-3 .33..mm.-3 .3...3..-3 .m:..33.- ..3..33.3 ..n..:3.3 .3...;u.3 a. .3. :.. .m. 3.. 3a. 33. >. 2.: .3...3m.-3 .>..-.33.-3 . a..nn.-3 .3..-.3n.- .33..3r.-3 .3“..u..-3 .»3..3..3 :3. .3.- 33. >fi.- 3 n.. .3. ... 3.: 8 . .3 .l J.. .l N .a. .I .. . .. . .. . .. . nu .3. . 3 .33 :n 3 ... 3. 3 ..n 33 3 .:3 3: -3 .3. 3. -3 .33 3: -3 1L 3.. 33.- 33. 33. 33,- 3.. 3..u .. 3.: A~.%.awc.lv Aoc.n.~:.lv A37..ao%.lv AOC..~L .V Aa43.9m~:.lv Afima..afi%.|v Afi.«~.nm-£.v 33. 3..- 33.- mg. .n.- :3.- 3». . 2.: .33..>3.-3 .....3m.-3 .>...3..-3 .3...33.- .n3..3..-3 ..:..m3.3 . u.....-3 ... :o.- 33.- m3. :..- :3. >3. .. mu; A§W..~.3.IV Ahma..~.3.lv Aaw~".a3~.lv ADO..$~.V Aflqoa.....lv Acn..«,~.lv A.:‘.am¢.¢.|4 3.. n.. 3.. n3. :3.- 33. n3.- . 3:: an..m3.-3 .33.-.>3.-3 .33.. 3.3 ..m..33.3 .33.-.»3.-3 .....c3.3 .33..:3.3 D. 3.2.! :m . 0.1.. 2* .i 2.1.. 2:. ..:...J>.3 un .. 23.33:. 2:33.333 :z< ... 23.33:. 2:33.332 :33. n33<333 z. n3. 3.3 >.. .3.- .3.- mm. 3 no. ::.- .. 32: .3...~m.-3 .....o..-3 .33..~m.3 .m......3 .3:..m3.-3 .~:..m3.-3 ..3..33.-3 ... 3.3 33.- 3.. .n. .m. :o. :3. Ax.- .. my: .3433 .8233 ......m..-3 3......3-3 ........m.-3 ......333 ...... ...-3 : ...: .3. mo. ... om. ...- .r. 3 . mu: .m....3.-3 .mm..~..-3 .3...3..-3 .33..m~.-3 .N...~..-3 .3...3o.-3 .3....3.-3 . 3.: mm. 33. ... mo. 3.. 3.. m. . my: .3...33.-3 .mm..>m.-3 .33..»c.-3 .3....o.-3 . 3..ou.-3 ..u..wm.-3 .33.-.3..-3 3.. .3.- .3.- mm. . 3 .3. .m.- >. 3.: 3.373 .3283 23...“; 23.5.3 23.5.3 37.3.3 .3 .-.3...-3 m..- 3.. 3:. 3.. w..- ... n.- ... 3.: .nn..33.3 .mm..wm.-3 .....m..-3 .3....o.-3 .»...~..-3 .n:..m3.-3 .33..3m.-3 .3. no. 3.. on. ...- .N. 3 .. 3.3 23:37-3 2.13.13 .23-3.3-3 .3...N3.3 ...-#9.; ...-.3-3 ...-:3-3 3%. ww. N.| AN. :f CM.I 33.1 3a.... .....m..-3 .....m..-3 .....mo.3 .mm..m3.3 .3m..33.-3 .3...>..-3 .3...3..-3 me. as. m. “N. NH. O .....x : mu: .m...3..3 .....m..-3 .33..>3.-3 .nm..o..-3 .....3..-3 .33..33.-3 .Nu...3.-3 .m. we. ... 3.. .o. 3.. 33. . mu: .m......-3 .3~.on.3 .n3..3..3 .pb..33.3 .»..-.os.-3 ..A..mo.3 .33.-....-3 3 no. 33. 3». m3.- 3. 3..- ..=.U>3 um<=3 aaV 9:. mo 4 we. moi 9.- V2.4 4.4.34 2.4 VV my: 21.2.; 3:3; 8.4...V..4..-V $1.5; V2.51; :5. 23; ELEV :V i: 2.4 .3. 3. m7- 3.4 .Vn. Va. VV mu: 2:13.; 3m..3.-V :V.4.X4.m.-V EH..o._.4V Sm}; -V Ann..em.-V SVLZIV Z 5: moi so. .5. 9.. .2. ..of I. V mu: A:h.a>0.v AOm..mC.V Afi.—..V—O.IV ANN..MM.IV A.uu..: ..lv AOL..«\VC.IV A.~M,...4..3.IV H 2;: .4... 2. mm. no.4 . no 4 a 0.. V m4: 2:; me 3?.mus ABLSFV 2.0.5.; 21.3.; ASLVVVVEV V2.4.me 3.4 co. no.4 2.- . :f mm.. 3.4 i 5:. A034lann.lv Am.~..HO.V AnN.. .Iv A3#.—ao.lv AAA..Qm.Iv AQH.I~DO.IV AND..CN.V :.- VVm. .Vo. - 3. .41- EVE o... VVV EVV :VV..V.«.-V 37.3.4V S4...mc.-V ANV..o.V.-V 37.2.; A .....On V SVV..V.14V 8.- ac. .3. 9.- .VV. .VVV. 4 3. VV 9:. in)“: V813V 3.25. V ELEV 23.-.}.-V 21:4. .-V 3%... V a. mu. ex. N... Dn.| Na... V.:. V ...:V 21.8.; V8.61; 37.2.; 3013.; 33:3.-V 33.4.21; 24:3 o.-V 3.. .5. c m..- 3.4 3.4 we. I ma: 3426 -V V4. 1.3. V 37.5.; 21.74:; VELVVEV 37.3.; 34....2VV 2. 3. «... 8.- a 3. no. V mu: Rafi-I-N.—.lv A.—O..Q._.V AG—4-33. IV AO._..$N.V AAJ...—3.w A\44.I.N.~.lv Afin...:..v 24.: an. 5.1.. 2. «7| 9... 2:...45: 55V: 555 .42qu .4..V_.- >V.- 2 0V.- V mu: Voq..ca.uV Vofl..mm.4V V>V..:m.-V AVM..QH.IV Asa..mu.4V Voz..Vo.-V AVA..ao.V V :V: VV.- VV.- no.. co. co. m.. «V. _ my: Ame..VV.-V VVn..oo.V Aam..mV.V VNV..wo.4V .mm..VV.V Vac..mm.lV AwV.4.an.-V om.- Mfi. mg. Hm. am. nV.- V4.4 >_ 1;: AMV..Vo.-V Van..c~.V AV“..mo.-V VVw..om.V VP“..;V.V Vw0.4.V:.4V A:V..>n.-V an. NV. oV. $4. 04. >V.- ac.- V_V =;: :m.-. a; 89.3.; RYE; 31.3.; 3:3,; Sula; 21.3.; co. .m.- uV. V..- NV.- 3 0V.- VV 3;: Vofi..fis.V Awe..On.V AV“..nV.4V Au»..V:.V Ana..cV.-V AVA..no.V AVA..n:.V on. mm. no. no. 5V.4 V“. Vn. V 5.: Am...nz.-V AHV..om.V Agm..n~.V AVV..mo.V Roz..m_.V Ans..mo.-V Vao.4.V:.-V .9. mm. am. m. an. NT: 9..- VV my: Va...>V.-V Ann..mo.4V AVV..om.V AVA..mV.4V AMV..VV.-V Ac“..;o.V Van..ao.-V o o_. «3.: mo. no.- nV. nV. V mu: A>»..~w.V as»..mo.V A»V..mo.-V VVs..wn.V V>n..o;.V VVa..mm.-V And..VV.-V .13 9.. so. no. 3... 3a. a 3 _V:.Vv>: =V Soil-Serum -.lh - 1h - 19 Phosphorus (-.3o,.os) {-.30, .05) (-.36, - .03) Soil-Serum -.2h -.06 -.18 Copper (-.ho,.1o) {-.22, 11) (-.33,.o1) Sell-Serum -.h5 -.h3 / - .25 \ Iron {-.ST,-.29) <- 5 ,--2h) \'-l‘lg - OS Soil-oerum .h3 .hT / .h9 \ Selenium (.27,.su) ( <2,.60) 4.3h,.6o/ sell-Serum —.08 .13 .06 Zinc (-.h1,.1o) (-.07,.25) (-.13,.2o) ~ - .13 3011 Iron .35 .28 , Serum Copper (.l9,.h6) (.ll,.h6) {-.079-25) ) Soil Iron .hl .30 \ .34 Blood 33 (.22,.57) ( 10, h1; (.18,.so) o 20 ”oil Iron -.27 -.01 1. gloom {T (—.uo,-.1o) (— 20,.20) (-._9,.1u) aHumbers in parenthesis are .95 cc cnfi dence Limit v—v -/ I \ LL 31». Koont'i, 113 COWS _LI:dRS CALVES Soil Calcium -.22 O2 - .25 Serum Magnesium (- 9 -.O3) (- 19,.lh) (- hl, - .05) Soil Calcium .h 27 - .01 Serum Phosphorus ( 3h, 60‘ (.lO,.h2) (- l9, .lh) Soil Calcium -.29 -.20 - .18 Serum Copper <- e5,-.12) (- 36,—.3h, (- 32, - 03) Soil Calcium .35 .35 .26 Serum Zinc (.l9,.50) ( 19,.50) (.06,.h2) Soil Potassium .02 .15 - .09 Serum Magnesium {-.l ,.lh) (.Oh,.30) {-.25, .11) Soil Copper .h0 .h3 .27 Serum Iron (.23,.55) (.27,.5h) (.lO,.h2) Soil Copper .21 .23 .23 Serum Selenium ’ 03,.36) (.03,.39) (.03,.39) Soil Copper .19 , .21 .15 Serum Zinc (.02,.37) K.03,.36) (.Oh,.30) Soil Copper - .36 -.23 -.31 Blood H3 (- so, - .19) {-.uo,-.ou) (-.u6,- Soil Copper .20 .21 , ‘ O 31ood HT ( 08,.30) (.03,.36) 1- 17,.19) Soil Zinc 08 — .02 .Ol \ (- ‘1,.1o> (-.2o, .19) (- 19,.18, Serum Copper aiumbers in parent? 3315 are .95 confidence 114 CORRELATIONAL COEFFICIENTS BETWEEN MINERALS IN GRASSES AND MINERAL AND HEMOGLOBIN AND HEMAIOCRIT FROM SAMPLES OF THE NORTHERN (REGION II) AND SOUTHERN (REGION I) VERACRUZ, MEXICO.a COWS :TIILRS CALVES Grass-Serum O .03 -.lO Caioium (-.17,.19) (- 13,.11) (- 27,.09) Grass-Serum -.35 —.2h -.2h Potassium (-.so,-.18) (- ho,.1o) (- ho,.1o) Grass-Serum .Oh .Oh .lh Magnesium {-.15,.25) (-.16,.25) (- 05,.2h) Grass-Serum .35 .21 -.Oh Phosphorus ( 19,.u6) ( 03,.36) (-.21,.11) Grass-Serum -.lS -.l3 -.l9 - Copper (-.30,.30) (- 30,.07) (-.36,-.Oj) Grass-Serum .39 .30 I .23 Iron (~239-5L‘) < lo, 1‘1} \-O3,-39) Grass Serum .08 27 .23 Selenium (- 01,.27) ( 10,.h2) (.03,.39> 26 Crass-Serum .26 .18 . Zinc < oe,.u2) ( 01,35) (.oo,.u2) Grass-Iron - 1h / -.O6 \ --O7 1\ Serum Copper ’- 30,.05) k-.22, ll, (-.2S,.l_, - - h -.35 Grass iron -.35 ‘3 Blood 53 (- 50,—.18) <- 19,- 18) (-.so,—.18) Grass Iron .20 ~07” / _0511\ Blood HT (.08,.30) (- 13,.40) \- -),._1, ajumbers in parenthesis are .95 confidence limits. 115 TJ“’7 AlS. (cont'd3 3W8 EEIIERS CALVES Grass Calcium -.26 -.08 -.27 Serum Magnesium (- hl,-.08) (- kl,.lO) (-.hO,—.lO) Grass Calcium .37 .l5 -.07 Serum Phosphorus (.2l,.5h) (-.OS,.2h) (-.25,.ll) Grass Calcium - 30 -.2h -.2h Serum Copper (- h5,-.12) {-.hO,-.lO) (-.hO,-.ll) Grass Calcium 29 .33 .28 Serum Zinc (.l2,.h6) (.12,.h8) (.ll,.h2) Grass Potassium .05 -.l2 -.l0 Serum Magnesium (- 15,.ll) (- 03,.05) (- 27,.09) Grass Copper .20 13 -05 Serum Iron ( 33, 37) (- 0t, 25) (- 15,.ll) Grass Copper -.32 lo .03 Serum Selenium (~.20,.lh) (- 10,.25) (~loa-hl) Grass Copper .13 l .03 Serum Zinc (-.07,.25) (—11,.27) (.1o,.u1) Grass Copper -.2T ‘-21 -.lh Serum as («ML-.10) (- 37,--02> (* 32,-02) Grass Copper .25 18 “'06 \ Serum :3: (.ou,.39) COL-35> (- 22:11! Grass Zinc -.25 — 18 -.l9 Serum Copper (- bO,-.C6) (- Q2 —.03) (- Q6,--03) 3? confidence limits. umbers in parenthesis are .95 116 CORRELATIONAL COEEEI IENTS BETWEEN HINERALS IN SERA OF COWS,\ HEIFERS AND CALVES, FROM SAMPLES OF THE NORTHERN (REGION II) AND SOUTHERN (REGI N I) VERACRUZ, MEXICO.a TABLE A16. CCA .25 HECA COCA .32 c . c A (.sh,.39) CALCA (.1S,.so) srna ' ‘1 46) WV“ \O‘nd’o For 32 cox .28 33K .hu VVAb O ...... .. ‘/ n .. ’ -- i . -- / —/\ 3;“ (.-3,.4C) pAmfi .-l,.~2: CAL; (.2T,.)O, some .23 some .35 HEMG .3h .... , - .. ’\ -_- / .— \ .msMG ;.33,.39) -1AEMG (.19,.ho; calms (.18,.>o/ Lg L... .621 so ?0 cos , .- '11 (.6o,.7?} :ALP (.3u,.6h) CAL? (.52,.72) FA 7 ~ s".- 77 :7 1v ’ ‘ \ v .’ ‘ *1 s r ~77 ( ~ \ u.Cu '—.34,.30) CALCU (.Ql,.37) onLCu k-.l0,.25/ -..”? ’ /" ‘, , a "n“. ’ I m ‘ A's—W I/ " :40; ‘036,oo"’} : T::¢ (.20,.4;l| C.L-.‘v.":‘ \‘2h,°)b) fin v-w r- v1 . ""H(VH ' Co E .7) C385 .30 AEDE .33 .‘C-Qflfi ,/ /' A up A _fi T H -v C‘ \ 1;: f" . a 3“ , 0 50 f :A—LLSE < o l 3 ’ 0 Ch «4.13.521 { o I , 0 OS / on v .2u COZN ‘ sz1 ~3“ :1": 1. [.02,.i‘l> CALLZN (-.OR .32) CALZI‘I K.lS,.SO> 1 BIBLIOGRAPHY 1. Amnerman, C. B. and Miller, S. M. 1972. Biological availability of minor mineral ions: A review. Journal of Animal Sci. 35(3) :681-694. 2. Anmennan, C. 8., Miller, S. M., Flic, K. R., and Hansarrd, S. I. 1977. Contaminating elements in mineral SLpplements and their potential toxicity: A review. Journal of Animal Sci. 44:485-502. 3. Anonymous. 1971. Selenium in nutrition. National Academy of Sciences. Washington, D.C. 4. Anonymous. 1978. Calcium and Phosphorus in animal nutrition. International Minerals and Chemical Corporation. Mundelein, Ill. 5. Anonymous. 1981. Potassium in Animal Nutrition. International Minerals and Chemical Corporation. Mundelein, Ill. 6. A.O.A.C. 1975. Official Methods of Analysis. 12th Edition. Association of Official Analytical Chemists. Washington, D.C. 7. Baker, S. B. and Reid, R. L. 1977. Mineral concentration of forages species grown in central West Virginia on various soil series. West Virginia University, Agricultural and Forestry Experimental Station. Bulletin 657. 8. Barradas, H. V. 1980. Interrelationship among the mineral content of soils, forages and cattle in the central and northern region of Veracruz, Mexico. M.S. Disserta- tion. Michigan State University. 9. Beeson, K. C. and Gennard Matrone. 1976. nutrition animal and human. Marcel Dekker, Inc. Studies on Selenium in plants and soils. Research Establishment The soil factor in New York. 10. Bisbjerg, B. 1972. Danish Atomic Energy Commission. Riso. Riso, Report Zoo. Darmark. Blue, W. G., C. B. Armienman, J. M. Loaiza, and J. F. Gamble. 1969. Compositional analysis of soils, forages and cattle tissues from beef producing areas of eastern Panama. Bio. Sci. 19:616. 11. 117 118 12. Blue, W. G., and L. E. Tergas. 1969. Dry season deteriora- tion of forage quality in the wet dry tropics. Soil and Crop Science Society of Florida. 29:224-238. 13. Booth, C. C. 1967. Sites of absorption in the small intes- tine. Federation Proc. 26:1583-1588. l4. Bowen, H. J. M. 1966. Trace elements in Biochemistry. Academic Press. New York. 15.— Boyd, C. E., and Knezer, D. B. 1972. Absorption reactions of micronutrients. _I_r_1 Micronutcients in Agiculture. J. J. Morthwedt, P. M. Giordand and W. L. Lindsay Eds. Soil Science Society of America Inc. Madison, Wisconsin. 16. Bremmer, I. 1970. Zinc, Copper and Magnesiim in the Alimentary Tract of Sheep. Br. J. NUtr. 24:769. l7. Brurby, P. J. 1974.~ Tropical pasture improvement and livestock production. World Animal Review. 9:13-17. 18. Buchanan-Smith, J. B. 1978. Calcium and Phosphorus requirements of dairy cows. First Annual International Mineral Conference, International Minerals and Chemical Corporation. Mundelein, Ill. 19. Buck, W. B. and Ewan, R. C. 1973. Toxicology and adverse effects of mineral imbalance. Clinical Toxicology. 6: 459-485. 20. Bush, D. H., Shull, H., and Conley, R. T. 1978. Chemistry 2nd Edition. Allyn and Bacon, Inc. 470 Atlantic Av. Bos- ton , Massachusetts. 21. Bush, L. P., Legget, J. E., King, M. J., and Vincent, J. E. 1981. Sulfur and molybdenum nutrition effects in tall fescue. Canadian Journal of Botany. 4:537-541. 22. Byer, Horace. 1937. Selenium in Mexico. Ind. and Eng. Chem. 29:1200—1202. 23. Byers, F. M., and A. L. Moxon. 1980. Protein and selenium levels for growing and finishing beef cattle. J. Animal Sci. 50: 1136-1143. 24. Cantor, A. H., M. L. Scott, and T. Noguchi. 1975. Biological availability of selenium in feedstuffs and selenium com- pounds for prevention of exudative diathesis in chicks. J. Nutrition. 1: 96— 105. 119 25. Cappon, C. J. and Smith, J. C. 1981. Mercury and selenium content and chemical form in human and animal tissue. J. Analytical Toxicology. 5:90-98. 26. Chertok, R. J., L. B. Sasser, M. F. Callahan and G. E. Jarboe. 1981. Influence of cadmium on the intestinal uptake and absorption of calcium in the rat. The Journal of Nutri- tion. 111:631-638. 27. Ctorch, D. C. 1979. Digestive physiology and nutrition in ruminants. Vol. 2-Nutrition. lst Ed. Oxford Press. Corvallis , OR. 28. Christiansen. W. C. 1971. Livestock feeds in Latin America. Institute of Food and Agriculture Science. International Minerals and Chemical Corporation. Mundelein, Ill. 29. Clanton, D. C. 1980. Applied potassium nutrition in beef cattle. The third Annual International Mineral Conference. International Minerals and Chemical Corporation. Mundelein, Ill. 30. Coell'o Da Silva, J. F. 1978. Copper and molybdenum in ruminant nutrition. In Latin American Symposium on Mineral Nutrition Research with—Grazing Ruminants. J. H. Conrad and L. R. McDowell Eds. University of Florida. 31. Conrad, J. H. 1978. Soil plant and animal tissue as predictors of the mineral status of ruminants. _I_n_ Latin American Symposium on Mineral Nutrition Research with Grazing Runinants. J. H. Conrad and McDowell Eds. University of Florida. 32. Cragle, R. G. 1973. Dynamics of mineral elements in the digestive tract of ruminants. Federation Proceedings. 8: 1910-1914. 33. Cunha, T. J. 1973. Recent developments in mineral nutrition. A look at the highlights of research involving the mineral requirements for swine, beef, cattle and horses. Feed- stuffs. 45:27-28. 34. Cymbaluk, N. F., Schryver, H. F., Hintz, H. F., Smith, D. F. and Lowe, J. E. 1981. Influence of dietary molybdenum on copper metabolism in ponies. J. of Nutrition. 1:96- 106. . 35. Davidson, Israel and John Bernard. 1974. Clinical diagnosis by laboratory methods. W. B. Samders Co. West Washington Square , Philadelphia. 36. 37. 38. 39. 41. 42. 43. 44. 45. 46. 47. 120 Davies, M. T., Soliman, H. S., Corrigal, W. and Flatt, A. 1977. The susceptibility of sucking lambs to zinc tomcity. Br. J. of Nutrition. 38:153-159. De Alba, J. 1971. Alimentacion del ganado en America Latina. 2a Edicion Ia Prensa Medica Mexicana . 127-154. De Oliveira Mendes. 1977. Mineral status of beef cattle in the northern part of Mato Grosso Brazil as indicated by age, season and sampling technique. Ph.D. Dissertation. University of Florida. De Sousa, J. C. 1978. Interrelationship among mineral levels in soil forages and animal tissues on ranches in nortl'ern Mato Grosso Brazil. Ph.D. Dissertation. University of Florida. Dregne, H. E. 1976. Soils of arid regions. American Elsevier Publishing Company, New York. ‘ Evans, G. W. and Johnson, E. C. 1981. Effect of iron, Vitamin B-6 and Picolinic acid on zinc absorption in rat. J. Nutrition. 1:68-75. Fehsh, M. S., W. J. Miller, R. P. Gentry, M. W. Neathery, D. M. Blakmon and S. R. Heinmtiller. 1981. Effect of high but not toxic dietary intake of copper and selenium on metabolism in calves. J. Dairy Sci. 64:1700-1706. Fenner, H. 1979. Magnesium nutrition of the ruminant. The second Annual International Minerals Conference. Inter- national Mineral and Chemical Corporation. Mendelein, Ill. Fick, K. R., L. R. McDowell and R. H. Houser. 1976. Current status of mineral research in Latin America. Department of Animal Science. University of Florida. Fisher, G. R. and Prentice, B. A. 1976. Copper-64 and Molib- denum- 99 metabolism in yomg cattle with molybdenum- induced copper deficiency. _I_n_ lVblybdenum in the Environ- ment. Vol. I. Chappell and Petersen Eds. Canther, H. E. 1974. Biochemistry of selenium. In Selenium. R. A. Zingaro and Copper Eds. Van Nostrand Reinhold Company. New York. Gavillon, O. 1970. Levantamento da compocipao mineral dos pastagens natives do Rio Grande do Sul. Departamento de Producao Animal Divisao de Zootecnia. Boletin 3a. Edicao . 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 121 Gomide, J. A., C. H. Moller, G. O. Mott, J. H. Conrad and D. L. Hill. 1969. Mineral composition of six tropical grasses as influenced by age plant and nitrogen fertili- zation. Agroncxmy Journal. 61:120-123. Gamide, J. A. 1976. Composicao mineral de gramineas e legumi- nosas forrageiras tropicais. Simposio Latino Americano sobre pesquisa em nutricao mineral de rumiantes en pastagens. Belo Horizonte Brazil. Goodrich, R. D., T. S. Kahlom, and D. E. Pamp. 1978. Sulphur in ruminant nutrition. A literature review. National Feed Ingredients Association. West Des Moines, Iowa. Grege, J. L. and Snedeiler, S. M. 1980. Effect of dietary protein and phosphorus level and the utilization of zinc, copper and manganese by adults. J. Nutrition. 110: 2243-2249. Hale, M. G., Foy, C. L. and Shay, F. J. 1971. Factors affecting root exudation. Adv. Agrom. 23:89-109. Hardison, W. A. 1966. Chemical composition, nutrient content and potential milk producing capacity of fresh tr0pical herbage. Dairy training and Research Institute. Univer- sity of Phillipines. Harker, D. B. 1976. The use of molybdenum for the prevention of nutritional copper poisoning in housed sheep. The Veterinary Record. July 31. Healy, W. B. 1974. Ingested soil as a source of elements to grazing animals. _I_n_ Trace element metabolism in animals-2. Proceedings of the second International Symposium on Trace Element Metabolism in Animals. University Park Press. Baltimore. Hill, C. H. 1975. Interrelationships of selenium with other trace elements. Federation Proceedings. 30:2096-2100. Hoekstra, W. G. 1975. Biochemical fmction of selenium and its relation to vitamine E. Federation Proceedings. 30: 2083-2089. Hsu, F. S., L. Krook, W. G. Pond, and J. R. Duncan. 1975. Interactions of dietary calcium with toxic levels of lead and zinc in pigs. J. of Nutrition. 1:112-118. Huber, J. T., Price, N. O. and R. W. Fmgel. 1971. Response of lactating dairy cows to high levels of dietary molyb- dean. J. Animal Sci. 32:364-367. 60. 61. 62. 63. 64. 65. 66. 67. 69. 70. 122 Huisingh, J., Gomez, G. G. and Matrone, G. 1973. Inter- actions of copper molybdenum and sulfate in ruminant nutrition. Federation Proceedings. 8:1921-1924. Jacobson, D. R., Hemken, R. W., Button, F. S., and R. H. Hatton. 1972. Mineral nutrition, calcium, phosplorus, magnesium and potassitm interrelationships. J. Dairy Sci. 55:935- 944. Jardin, W. R., A. M. Peixoto, C. L. De Morais, and F. Silveira. 1965. Contribution to the study of the chemical ccnposition of forage plants from pastures in central Brazil. Anaes de IX Congreso Internacional de Pastageas, Sao Paulo. Brasil. Jones, B. J. 1972. Plant tissue analysis for micronutrients. In Micronutrients in agriculture. J. J. Mortuedt, P. M. Giordano and W. L. Linsday Eds. Soil Science Society of America Inc. Madison, Wis. Kalinowski, Juan. 1979. The mineral composition of native forages from the Peruvian Andean highlands. Department of Nutrition, Universidad Nacional Agraria La Molina. Lima, Peru. Kayongo-Vlale, H. and J. W. Thomas. 1975. Mineral composition of some tropical grasses and their relationship to the organic constituents and estimates of digestibility. E. A. Agric. For. J. 40:428-439. Kayongo-Male, H. , J. W. Thomas, D. E. Ullrey, R. J. Deans and J. A. Arroyo-Aguilu. 1976. Chemical composition and digestibility of tropical grasses. Journal of Agriculture of Puerto Rico. 2:186-200. Kemp, A., W. B. Deijs, 0. J. Hemkes, and Van es A. J. H. 1971. Hypomagnesemia in milk cows: Intake and utilization of magnesium from herbage by lactating cows. Neth. J. Agric. Sci. 9:134-149. Kendal, W. K., and Nelson, 0. P. 1966. Nutritional value of Haitian forages. Archivos Iatinoamericanos de Nutricion. 15:221-230. Kemneth C. Beeson and Guillermo-Gomez. 1970. Concentration of nutrients in pastures in the central Huallana and Rio Ucayali valleys of the upper Amazon basin of Peru. Proceedings of the )0: International Grassland Congress. Kincaid, R. L. 1980. Toxicity of amonium molybdate added to drinking water of calves. J. Dairy Sci. 63:608-610. 71. 72. 73. 74. 75. 76. 77. 78. 79. 81. 82. 83. 123 Kincaid, R. L., J. K. Hillers and J. D. Cronrath. 1981. Calcium and prospl'orus supplementation of rations for lactating cows. J. Dairy Sci. 64:754-758. Kincaid, R. L. 1981. Factors associated with the variation of copper and zinc in plasma of lactating cows. Nutri- tion Raports International. 3:493-498. Korte, N. E., J. Skopp, W. H. Fuller, E. E. Niebla, and B. A. Alesii. 1976. Trace element movement in soils: Influence of soil physical and chemical properties. Soil Sci. 6:350-359. Kubota, J., W. H. Allaway, D. L. Carter, E. E. Cary and V. A. Iazar. 1967. Selenium in crops in the United States in relation to selenium-responsive diseases of animals. J. Agr. Food. Chem. 15:448-453. Lang, Rojas C. E. 1974. Phosphorus and trace mineral status of beef cattle in tie Guanacaste region of Costa Rica. Thesis. University of Florida. Lindsay, W. L. 1972. Inorganic phase equilibria of micro- nutrients in soils. In Micronutrients in Agriculture. Soil Science Society 07' America Inc. Madison, Wisconsin. Linser, J. R. 1980. Potassium, Animal Nutrition and Health, Mineral series. California Farmer Publishing Company. Matrone, G. 1974. Chemical parameter in trace-element antagonism. In Trace element Metabolism in Animals-2. University P ark Press, Baltimore. Mertz, W. 1970. Some aspects of nutritional trace element research. Federation Proceedings. Fed. Am. Soc. Exp. Biol. 29:1482-1487. Mertz, W. 1981. The essential trace elements. Science. 18:1332- 1338. Miller, E. R. 1979. Bioavailability of minerals. Animal Husbandry Department. Michigan State University. Miller, J. K., Moss Bell, M. C. ,and Snead, N. W. 1972. Comparison of9 9% metabolism in young cattle and swine. J. Animal Sci. 43: 846- 852. Miller, R. F. , and Engel, R. W. 1960. Interrelation of copper molybdenum and sulfate sulfur in nutrition. Federation Proceedings. 2:666-671. 84. 85. 86. 87. 88. 89. 91. 92. 93. 94. 95. 124 Miller, W. J. 1970. Zinc nutrition of cattle: A review. J. Dairy Sci. 53:1123-1127. Miller, W. J. 1975. New concepts and developments in metab- olism and homeostasis of inorganic elerents in dairy cattle. A review. J. Dairy Sci. 58:1549-1560. Miller, W. J. 1979. Copper and zinc in ruminant nutrition. National Feed Ingredients Association. One Corporate Place. West Des Pbines, Iowa. Mills, C. F. 1974. Trace elements interactions: Effect of dietary composition on the development of imbalance and toxicity. _I_n_ Trace Element Metabolism in Animals-2. University Park Press, Baltimore. Mills, C. F. 1980. Mineral absorption principles and applied considerations. Tie third annual International Mineral Conference International Mineral and Chemical Corporation. Mundelein, Ill. McDowell, L. R. 1976. Beef cattle production in developing countries. University of Edinburgh, Centre for Tropical Veterinary Medicine. _ McDowell, L. R. 1977. Geographical distribution of nutritional diseases in annual "CRC Handbook of Nutrition and Food." Institute of Food and Agicultural Science. University of Florida. McDowell, L. R., J. H. Conrad, J. E. Thomas, L. E. Harris and K. R. Fick. 1977. Nutritional composition of Latin American Forages. Trop. Anim. Prod. 2:273—279. McDowell, L. R., C. E. Lang, J. H. Conrad, F. C. Martin, and H. Fonseca. 1978. Mineral status of beef cattle in Guanacaste, Costa Rica Trop. Agric. 55:343-350. National Research Council. 1976. Nutrients of beef cattle. Nutrient Requirements of Domestic Animals. National Academy of Sciences. Washington, D.C. National Research Council. 1978. Nutrient requirements of dairy cattle. Nutrient Requiretents of Domestic Animals. National Academy of Sciences. Washington, D.C. National Research Council. 1980. Mineral tolerance of domestic animals. National Academy of Sciences. Washington, D.C. 125 96. Nelson, 1‘. S. 1980. Phosphorus availability in plant origin feedstuffs for poultry and wine. The third ammal Inter- national Minerals Conference. International Mineral and Chemical Corporation, Mendelein, Ill. 97. Newton, G. L., J. P. Fontenot, R. E. Tucker and C. E. Poland. 1972. Effects of high dietary potassium intake on the metabolism of magnesitm by sheep. J. Animal Sci. 35: 440-449. 98. O‘Dell, B. L. 1960. Magnesium requirement and its relation to other dietary constituents. Federal Proceedings. 19: 649-653. 99. O'Dell, B. L., E. R. Marres, and W. O. Regan. 1960. Magnesium requirements of guinea pigs and rats. Effect of calcium and phosphorus and symptoms of magnesium deficiency. J. Nutrition. 70:102-110. 100. Olsen, S. R. and Kemper, W. D. 1968. Moverent of nutrients to plant roots. Adv. Agron. 20:91-151. 101. Olsen, S. R. 1972. Micronutrient interactions. .13. Micro- nutrients in Agriculture. J. .C. Mortuedt, P. M. Giordano, and W. L. Lindsay Eds. Soil Science Society of America, inc. Madison, Wisconsin. 102. Olson, I., S. Palmer and E. E. Cary. 1975. Modification of the official fluorimetric mettod for selenium in plants. J. Ass. Off. Anal. Chem. 50:117. 103. Peeler, H: T. 1972. Biological availability of nutrients in feeds: Availability of major mineral ions. J. Animal Sci. 35:695-712. 104. Perdomo, J. T., Shirley, R. L., and Chico, C. F. 1977. Availability of nutrient minerals in four tropical forages fed freshly chopped to sheep. J. Animal Sci. 45:1114— 1119. 105. Pond, W. G. 1975. Mineral interrelationship in nutrition: Practical implications. Cornell Vet. 65:441-456. 106. Pope, A. L. 1971. A review of recent mineral research with sheep. J. Animal Sci. 6:1332-1343. 107. Pope, A. L. 1975. Mineral interrelationship in ovine nutri- . tion. J. Am. Vet. Med. Ass. 3:264-268. 108. 109. 110 . 111. 112. 113. 114. 115. 116. 117. 118. 126 Powel, G. W., Miller, W. J., Morton, J. D. and Clifton, C. W. 1964. Infltence of dietary cadmiim level and supplemental zinc on cadmium toxicity in bovine. J. of Nutrition. 84: 205-211. Powell, K. , Reid, R. L. and Balasko, J. A. 1978. Performance of lmzbs on perennial ryegrass, smooth bromegrass, orchard grass, and tall fescue pastures. II Mineral Utilization. In vitro digestibility and chemical composition of herbage. J. Animal Sci. 46:1503-1514. Ranhotra, G. S., C. Lee, J. A. Gelroth, G. L. Winterringer and F. A. Torrance. 1981. Bioavailability of iron magnesium, zinc and calcium in commercially produced citrate prosphate complexes. Cereal Chemistry. 58: 127-129. Reid, R. L. 1979. Effect of minerals and mineral availability on nutritive quality of forages. Runen function con- ference. Chicago, Ill. Reid, R. L. and D. J. Horuath. 1980. Soil chemistry and mineral problems in farm livestock. A review. Animal Feed Science and Technology. .5:95-167. Reid, R. L., Post, A. J., and Jung, C. A. 1970. Mineral composition of forages. Bulletin 5891‘. West Virginia University Agricultural Experimental Station. Rodriguez, E. 1979. Parametros Hematologicos normales en bovinos Cebu (Indobrasil) desde el nacimiento hasta el destete en clima subtropical A(f)c. Thesis, Universidad Nacional Autonoma de Mexico. Schalm, O. W. 1965. Veterinary hematology. 2d Edition. Lea and Febriger. Philadelphia, Pennsylvania. Schutte, Karl. 1964. The biology of the trace elements. Crosby Iockwood and Son Ltd. Bungay Suffolk, England. Scott, M. L. 1972. Trace elements in animal nutrition. In Micronutrients in agriculture. Soil Science Society 533' America. Madison, Wisc. Smith, B. P., Fisher, G. L., Poulos, P. W., and Irwin, M. R. 1975. Abnormal bone development and lameness associated with secondary copper deficiency in young cattle. J. Am. Vet. Med. Ass. 7:682—687. 127 119. Spears, J. W., Bush, L. P., and Ely , D. G. 1977. Influence of nitrate and molybdenum of sulfur utilization by rumen microorganisms. J. Dairy Sci. 60:1889-1893. 120. Sutmoller, P. , Vahia De Abreu, J. vanDer Grift and W. G. Sombroek. 1966. Communication. Mineral imbalances in cattle in the Amazon valley. Department of Agriculture Research of the Royal Tropical Institute. 121. Suttle, N. F. 1974. Effects of Molybdemm and sulphur at concentrations commonly found in ruminant diets on the availability of copper to sheep. _I_n_ Trace element metabolism in animals—2. University Park Press. Baltimore. 122. Suttle, N. F. 1975. Trace elerent interactions in animals. _I_n_ Trace elements in soil-plant-animal systems. D. J. D. Nicholas and A. R. Egan Eds. Academic Press Inc. New York. 123. Swaine, D. J. 1955. Selenium. Tech. Communication 48 Commonwelath Bur. Soil Sci. Rothamsted EXp. Stn. Harpen- den, England. 124. Thompson, D. J. 1978. Biological availability of macro- elenents. _I_r_1_ Latin American Symposium on Mineral Research with Grazing Ruminants. University of Florida. 125. Tinnimit, Parnich and J. W. Thomas. 1976. Forage evaluation using various laboratory techniques. J. Animal Sci. 5 : 1058- 1065. 126. Tisdale, S. L. and W. L. Nelson. 1975. Soil fertility and fertilizers. Macmillan Publ. Co. New York. 127. Ullrey, D. E., P. S. Brady, P. A. Whetter, P. K. Ru, and W. T. Magee. 1977. Selenium supplementation of diets for sheep and cattle. J. Animal Sci. 3:559-565. 128. Underwood, E. J. 1966. The mineral nutrition of livestock. Commem. Agric. Bur. The Central Press. Aberdeen, U.K. 129. Underwood, E. J. 1977. Trace elements in human and animals nutrition. Academic Press. New York. 130. Underwood, E. J. 1979. The current status of trace element nutrition: An overview. The Second Annual International Minerals Conference. Jan. 1979. St. Petersburg, Florida. 131. Vanderveen, J. E., and Keener, H. A. 1964. Effects of molybdenum and sulfate sulfur on metabolism of copper in dairy cattle. J. of Dairy Sci. 47:1224-1230. 132. 133 . 134. 135 . 136. 137 . 138. 139 . 128 Vanchikou, A. I. 1974. Zones of display of biological and phamacotoxicological action of trace elements. In; Trace elements metabolism in animals. W. G. Heekstra E . Vitosh, M. L., D. D. Warncke and R. E. Lucas. 1973. Secondary and micronutrients for vegetables and field drops. Exten- sion Bulletin E24486. Farm Sci. Series. Michigan State University. Ward, G. M. 1978. Molybdemm toxicity and hypocuprosis in ruminants: Areview. J. Animal Sci. Z+6:1O78-1085. Warncke, D. D. and L. S. Robertson. 1976. Understanding the M.S.U. soil test report: Results and recommendations. Bulletin 937. Cooperative Extension Service. Michigan State University. Wasserman, R. H. 1960. Calcium and phosphorus interactions in nutrition and physiology. Federation Proceedings. 19:636-673. Webster, S. W. 1979. Cadmium-induced fetal growth retardation in mice and the effects of dietary supplements of zinc, copper, iron and selenium. J. Nutrition. 190:1646-1651. Wilkinson, H. F. 1972. Moverent of micronutrients to plant roots. _I_n_ Micronutrients in agriculture. Soil Sci. Soc. Am. Madison, Wisconsin. Woodruff, J. R. and E. J. Kamprath. 1965. Phosphorus absorp- tion maximum as measured by the langmuir isotherm and its relationship to phosphorus availability. Soil Sci. Amer. Soc. Proc. 29:148-153. MICHIGAN STQTE UNIV. LIBRQR | 1 1| HHIHI H 3129310668545. IES