r I W W 25I55259 lllilllllllllllllll 'Micfifi‘iii‘lm ' University This is to certify that the thesis entitled Effect of Water Flow Rates on Performance of Nursery Pigs and Influence of Pressure on Flow Rate from Nipple Waterer presented by JOSE ENRIQUE CELIS has been accepted towards fulfillment of the requirements for M. S. . A. E. degree 1n gym/MW Major professor Date August 26, 1988 07639 MSUix an Affirmative Action/Equal Opportuniry Institution PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. DATE DUE DATE DUE DATE DUE MSU Is An Affirmative Action/Equal Opportunity Institution " ‘5‘ x&- -M’. EFFECT OF WATER FLOW RATES ON PERFORMANCE OF NURSERY PIGS AND INFLUENCE OF PRESSURE 0N FLOW RATE FROM NIPPLE WATERER BY Jose Enrique Celis A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Agricultural Engineering Department of Agricultural Engineering 1988 ABSTRACT EFFECT OF WATER FLOW RATES ON PERFORMANCE OF NURSERY PIGS AND INFLUENCE OF PRESSURE ON FLOW RATE FROM NIPPLE WATERER BY Jose Enrique Celis The effect of water flow rates on performance of pigs weaned at 28 days of age was studied. In Trial I, ninety six pigs were allocated in eight 1.22 x 2.44 m pens with 2 drinkers per pen. In Trial II, forty eight pigs were allo- cated in eight 1.22 x 1.22 m pens with one drinker. Pigs in iboth trials were given access to a water flow rate of 70 and 700 ml/min for 28 days. Results from Trial I demon- strated that rate of gain, feed intake and feed conversion decreased significantly for pigs on the 70 ml/min water flow rate at week 4 after weaning. In Trial II there were not statistically differences on pig performance. For pigs heavier than 16 kg housed at temperatures higher than 26°C, the water flow rate should be increased above 70 ml/min. The effect of water pressure on the variability of water flow rate was evaluated. The water flow rate was measured for a 35 to 400 KPa range of pressure. It demon- strated that if the water supply system provides pressures in the range of-140 to 400 KPa, the nipple waterer studied will repeatedly supply either 70 or 700 ml/min water flow. ACKNOWLEDGEMENTS The author wishes to express a deep gratitude to Dr. Howard L. Person (Agricultural Engineering) for his inter— est, guidance and support while serving as the major pro— fessor. To Dr. Andrew J. Thulin (Animal Science) for his spe- cial and stimulating support during the experimental phase of the project. Many thanks are due to Dr. Larry J. Segerlind (Agricul- tural Engineering) as a committee member and for his useful lectures during the course of the academic program. To Dr. Merle C. Potter (Mechanical Engineering) for his assistance in conducting the flow mechanic experiment. Also many thanks to Dr. John L. Gill (Animal Science) for his guidance during the statistical analysis of the data. The author extends his appreciation to Fulbright-LASPAU for the financial assistance to help make this graduate program possible. Finally, the author wishes to give a special note of appreciation to his wife Iris and his sons Bastian and Christopher for their love, encouragement, patience and company. ii TABLE OF CONTENTS LIST OF TABLES .OOOOOOOOOOOOOOOOOOO. ........ 0.0.000... LIST OF FIGURES ..... ..... ........ .................... 1. INTRODUCTION OOOOOOOOOOOOOOOOOOOO0.0.0.0.000.000... 1.1 Background ......................... ..... ....... 1.2 Objectives ...... ...... . ...... ............ ...... 2. LITERATURE REVIEW ........ .. ....................... 2.1 Water Function in Animals ..................... 2.2 Water Requirements of Pigs ........ ...... . ...... 2.3 Behavioral Response of Early Weaned Pigs ..... 2.4 Variability of Flow Rate on Frequent Watering . 3. METHODOLOGY .................... ................... 3 1 Experimental Facility and Animals .............. 32TrialIO0.000000000000000000000000 ........... .0 3.3 Trial II O.I...0.00.00.00.00...OOOOOOOOOOOOOOOO. 3.4 Management ...... ..... ...... ....... . ........... 3 5 Determination of Water Flow Rate and Pressure .. 36Statistics 0.00000000000000000COOOOOO00......0.. 4. RESULTS ............... . ...................... ..... 4.1 Trial I ........................................ 4.2 Trial II OOOOOOOOOOOOOOO ..... 0.... ...... 00...... 4.3 Behavioral Response of Nursery Pigs............. 4.4 Pressure and Water Flow Rate Variability ....... 5. DISCUSSION OOOOOOOOOOOOOOOOO0.000000000000000000000 iii vi 5 5 7 12 13 l6 l6 16 19 19 22 24 25 25 29 3O 33 37 6. CONCLUSIONS OOOOOOOOOOOOOOOOOOOOOOOOOOOOOO. ........ 42 BIBLIOGRAPHY ......................................... 44 APPENDICES 0.... ........ 00...... ...... O. OOOOOOOOOOOOOO 46 Appendix 1. Repeated measures analysis of variance for weekly growth rate (Trial I) ...... 46 Appendix 2. Repeated measures analysis of variance for average daily gain (Trial I) ...... 46 Appendix 3. Repeated measures analysis of variance for weekly feed intake (Trial I)‘ ...... 46 Appendix 4. Repeated measures analysis of variance for feed:gain ratio (Trial I) ......... 47 Appendix 5. repeated measures analysis of variance for drinker contact (Trial I) ......... 47 Appendix 6. Repeated measures analysis of variance for weekly water intake (Trial I) ..... 47 Appendix 7. Repeated measures analysis of variance for water:feed ratio (Trial I) ........ 48 Appendix 8. Repeated measures analysis of variance for weekly growth rate (Trial II) ...... 48 Appendix 9. Repeated measures analysis of variance for average daily gain (Trial II) ..... 48 Appendix 10. Repeated measures analysis of variance for weekly feed intake (Trial II) ..... 49 Appendix 11. Repeated measures analysis of variance for feed:gain ratio (Trial II) ........ 49 Appendix 12. Repeated measures analysis of variance for drinker contact (Trial II) ... ..... 49 Appendix 13. Repeated measures analysis of variance for weekly water intake (Trial II) .... 50 Appendix 14. Repeated measures analysis of variance for waterzfeed ratio (Trial II) ........ 50 Appendix 15. Individual weights for Trial I ........ 51 Appendix 16. Individual weights for Trial II ....... 54 iv LIST OF TABLES Treatment combinations for Trial I ............... 19 Treatment combinations for Trial II .. ....... ..... 21 Effect of water flow rate on overall performance of nursery pigs (Trial I) .... ...... . ............. 26 Weekly effect of water flow on mean weight, daily gain, feed intake and feed:gain ratio (Trial I) .. 27 Weekly effect of water flow rate on drinker contact, water intake, and waterzfeed ratio (Trial I)‘ ..... 28 Effect of water flow rate on overall performance of nursery pigs (Trial II) ....................... 30 Weekly effect of water flow on mean weight, daily gain, feed intake and feed:gain ratio (Trial II).. 31 Weekly effect of water flow rate on drinker contact, water intake and waterzfeed ratio (Trial II) ..... 32 Weekly flow rates and pressure for Trial I ....... 34 Weekly flow rates and pressure for Trial II ...... 36 LIST OF FIGURES Type and duration of protective immunity ......... 2 Floor plan of the nursery room ................... 17 Distribution of treatments in eight 1.22 x 2.44 m pens for Trial I ................................. 18 Distribution of treatments in eight 1.22 x 1.22 m pens for Trial II .................. .............. 20 Experimental equipment to measure water flow and pressure .... ..... . ..... . ....... . ................. 23 Effect of pressure on water flow rate ............ 35 vi 1 INTRODUCTION 1.1 Background One of the most crucial periods in swine production occurs after pigs are weaned and moved from farrowing units to nursery facilities at 3 to 5 wks of age. At this age, the pig is unable physiologically and immunologically to survive adequately in a stressful environment. The active antibody production in the young pig begins at approxi- mately three weeks of age (Figure 1.1). During the wk 3 and 4 after birth, the pig is highly susceptible to certain diseases. At this point it is crucial to provide optimal environmental and nutritional conditions that allow the pig to make adjustments as rapidly as possible. Yet environ- mental and nutritional needs change quickly. On the other hand, profitability in swine production depends upon maximizing annual production in terms of pigs marketed per sow. In consequence, weaning age becomes a compromise between allowing the pig’s own active immunity mechanisms to be completely developed and minimizing the time in the farrowing facility (Leman et al., 1986). 2 Intensive farming is continually being developed, and a greater number of animals are being housed within artifi- cial environments to satisfy production demands. This may From Colostrum 2 D 2 2 LL. 0 __, From Piglet LL! > LIJ .J 4 . ° ' .L ~ V fl Colustrum Intake 1 2 3 4 5 AGE IN WEEKS Figure 1.1 Type and duration of protective immunity (Brent et al., 1975). 3 induce stress on the animal in cases of high stock densi- ties or poor farm layout (Curtis, 1983). Inadequate space in indoor housing, water supply, food provision and trough space could produce animals that develop a dominant behav- ior at the expense of subordinate animals. The result would be a deterioration of health and general production. Among the nutrients required by livestock, water is considered to be one of the most important compounds, as it represents 71 to 73 percent of the fat-free body weight (Brent et al., 1975). Water is as important as feed for swine production since a reduction of water consumption may reduce feed intake thus causing a reduction in growth rate and worsening feed conversion. There is a major difference between the water needed for survival and that needed for optimum growth. The effect that daily water intake, Optimal flow rates, number of pigs per drinker, water quality, drinker location and configuration have on performance of nursery~age pigs are not clearly understood. Although, there are studies indicating that pigs tend to adapt to the time they are allowed to spend drinking (Yang et al., 1981; Nienaber and Hahn, 1984). However, water flow rates for optimal produc- tion are still unknown. Blockage, distance from the water pump and loss of pressure have an undesirable effect on water distribution systems by decreasing the water flow rate. On the other hand, too much water results in waste, wet sleeping areas, 4 increased slurry disposal and raised humidity 'in rooms. Another important factor to consider when designing a pipe- line water distribution system is that, high pressure can decrease water consumption. Also, a high head loss decreases the flow rate, so that the pigs do not receive enough water due to exhaustion from extended drinking peri- ods (Olsson and Andersson, 1985). Hence, a well designed water supply system must allow the pigs adequate water sup- ply and must operate at low cost. Although water consump- tion is important for pigs to produce at an optimum level, this component of pig production is often overlooked and there has been very little research on the subject. 1.2 Objectives 1. To determine the influence of water flow rates pro- vided by nipple valves on performance of pigs weaned at 28 days of age. 2. To study the variability of the flow rates in order to provide design specifications for water distribution systems in nursery facilities. 2 LITERATURE REVIEW 2.1 Water Function in Animals It is well documented that animals cannot produce to their potential without adequate feed and water intakes (Curtis, 1983). Water is one of the most vital nutrients that animals need to live. They are able to survive longer without feed than water. Ensminger (1962) stated that because this nutrient exists in abundance and can be provided at low cost, little emphasis has been given to water as compared to other nutrients under normal conditions. The question why not then provide water in abundance can be answered by taking into account some important limiting factors on the pig's performance. First, an excess of water will increase wast- age, therefore deteriorate the pen’s hygienic conditions. Secondly, an increased water supply would require a larger pump and pipeline distribution system, which is directly related to higher investment costs. Water is considered to be one of the largest single constituents of the animal body. It ranges from 40 percent in older pigs to 80 percent in newborn pigs. Ensminger (1962) determined that the amount of water in the body of an animal depends on its age and condition. As a rule, the 6 younger the animal the more water it contains. An older animal has less water per unit of body weight than a young animal because smaller animals consume less feed per unit of weight, and the water of its body is being replaced by fat. This is why gains in older animals are more costly than equivalent gains in younger animals. According to Ensminger (1962) and Gillespie (1981), water has many functions in animals and can be summarized as follows: 1. It is vital to the life and condition of every cell of the animal body. 2. It assists with temperature regulation in the body, so that the animal can control its temperature by perspira- tion in hot environments. But pigs do not regulate their rate of perspiration in response to environmental condi- tions. 3. It is fundamental for many of the chemical reactions such as digestion and metabolism which take place within the animal’s body. 4. It acts as a carrier of the nutrients to different parts of the body and removes waste products from tissues and organs. 5. It helps to dissolve nutrients the animal consumes. Hence, adequate amounts of fresh, clean water is necessary for animals to grow and produce for the benefit of people. Curtis (1983) indicates that dehydrated animals are 7 less heat tolerant than normal animals because dehydration reduces their ability to regulate body temperature by eva- poration. 2.2 Water Requirements of Pigs At present, water is often supplied by automatic drink- ing systems that can be equipped with heaters to keep the water from freezing when temperatures are extreme. The most common type of equipment for automatic systems are nipple-type or bite waterers which are low cost, allow free access and provide clean water. They are generally located in the dunging area to maintain the desired dunging pattern and preserve hygienic conditions in the pens. Another practical system to provide water automatically to pigs is the nose valve. In general nose valves are located above the feeding trough, so when the pig wants to drink, it pushes the valve using its nose. Since the pigs tend to play with nose valves or attempt to cool themselves in warm weather, it could result in the release of more water than needed causing wet feed, wet flooring, reduced manure storage time and increased labor. To control this undesirable situation, watering periods may be restricted only to the feeding periods by a preset timer control (Ols- son and Andersson, 1985). Olsson (1983b) found that water- ing only at feeding times may result in a lower water con- sumption, which may limit growth rate. He studied the- effect of the learning period for a nose valve system on 20 8 kg pigs. The results showed that the learning period was affected by such factors as the pressure necessary for the pig to release the water, the location of the nose valve in relation to the feeder and the size of the valve button. He concluded that the weight gain performance of the animals was affected by this type of valve because of a low water consumption which was a limiting factor on the growth rate of pigs. A great number of variables are related to .water con- sumption. Most of them have yet to be determined with pre- cision. Clearly, weight gain of pigs depends on water con- sumption. Large daily gains will require large amounts of water (Baxter, 1984). According to Gillespie (1981), a con— tinuous supply of water to animals is necessary for rapid growth and efficient production. When animals do not have an adequate water supply, there is inhibition of use of the other nutrients supplied in the feed. However, studies per— formed on young pigs recently have not clearly supported that point. Carlson and Peo (1982) found that a group of animals that gained less weight consumed 37 percent more water. Another group presented no difference between growth rate and feed conversion from water intakes-of 0.6 to l 1.d'1.pig'1. The Agricultural Research Council (1981) has summa- rized the water requirements according to classes of pigs. Typically, growing pigs need between 1.5 to 2 l per day at 15 kg liveweight and 6 l per day at 90 kg liveweight. Non- 9 pregnant sows require 5 l of water daily, while pregnant sows need 5 to 8 l per day and lactating sows need between 15 to 20 l per day. Baxter (1984) proposed that the water intake of pigs is a function of their need to maintain an adequate water bal- ance. The pig will adjust the water intake until it equal- izes the amount of water stored in body tissue plus the amount lost by the body. It can be denoted as W(intake) = W(stored) + W(lost) Water consumption depends on environmental conditions, diet, quality of water, animal size and physiological func- tion (Nienaber and Hahn, 1987). Ensminger (1970) had pre- viously made a similar statement, stating that the higher the temperature the greater the water consumption. At that time he found that water intake of pigs at a high room tem- perature can be as high as 4 kg of water per kg of dry feed. The amount of water lost by the animal’s body is a function of environmental temperatures; therefore, Baxter (1984) indicated that at high room temperatures the water consumption of pigs may be increased by as much as 100 per- cent. Mount et al. (1971) reported that 21 kg pigs pre- sented no difference in water consumption between 7, 9, 12, 20 and 22°C, but when the temperature was increased to 30 and 33°C the water intake was considerably increased. According to Curtis (1983), water restrictions of 25 to 10 50 percent of the requirement may lead to dehydration which is especially notable when animals are growing in a hot environment. In fact, the hotter the environment, the more quickly animals become dehydrated. Also, water restriction appears to decrease productive performance of pigs due to the feed-intake rate decreases with reduced water intake. Church (1984), demonstrated that water restrictions would result in a reduced rate and efficiency of weight gain in pigs and reduced milk production in lactating sows. Under normal feeding and environmental conditions the water consumption of animals is a function of feed intake. In general, the water requirements of lactating sows and their litters is satisfied by supplying two parts of water to one part of feed (Baxter, 1984). The Agricultural Research Council (1981) showed that early weaned pigs can satisfy their needs at a water to feed ratio of 2:1. Some studies suggest that young pigs can tolerate variances in the water supplied (Carlson and Peo, 1982). Even newly weaned pigs are able to adapt to a wide range of water to feed ratios (Nienaber and Hahn, 1984). Holme and Robinson (1965) evaluated pigs during a 18 and 90 kg liveweight growing period, but found no difference in performance for water to feed ratios of 1.5:1 and 2.5:1. The question is whether adaptation means diversion of resources that could prevent disease (Curtis, 1983). A study conducted by Yang et al. (1981) with 30 kg growing pigs showed that the pigs consumed more water when ll feed was restricted. At 25°C room temperature, pigs drank more water than normally required when they were given a daily limited supply of food of 0.8 kg to 1.5 kg. However, a study conducted by Castle and Castle (1957) showed that as the water to feed ratio varied from 1.5:1 to 3.8:1, it had no effect on overall performance of pigs, and they were still able to maintain the water balance. Nienaber and Hahn (1984) conducted an experiment in which they measured the effects of water flow restriction and air temperature on nursery pigs. Two trials were con- ducted to determine the effects of nipple waterer flow rates and environmental factors on the performance of pigs. In the first trial, 42 barrows at 10 weeks of age were housed at 5 or 35°C and fed for 4 wk using flow rates of 100, 600 and 1100 ml/min which were compared to a control group at 20°C and 600 ml/min. When pigs were housed at 35°C, the authors found a linear increase in weight gain from 0.28 kg/d to 0.47 kg/d at 100 ml/min and 1100 ml/min, respectively. On the other hand, pigs fed at 5°C had a decrease in weight gain from 0.86 kg/d to 0.73 kg/d at 100 ml/min and 1100 ml/min, respectively. It is also noted that the weight gain of pigs fed at 5°C and 600 ml/min were similar to that of the control group, averaging 0.76 kg/d. In a second trial conducted under commercial condis' tions, they used 120 pigs weaned at 4.5 wk and housed at 30°C; for 4 weeks. Water flows were provided at 100, 350, 600, 850 and 1100 ml/min. The results indicated that there 12 was no effect of water flow rate on body weight gain, feed intake or feed conversion of animals, even though water consumption decreased as water flow rate decreased. On the other hand, time spent drinking at 100 ml/min increased almost four times compared to the rest of the treatments. The study demonstrated that nursery-age pigs are adaptable to restrictions of water supply. Pigs were able to consume a sufficient amount of water by increasing time spent drinking to maintain growth rate. 2.3 Behavioral Response of Early Weaned Pigs Confinement of animals can result in many behavioral responses of health and performance, some of which are com- plicated and still not clearly understood. There is an erroneous tendency to assume that if human beings feel com- fortable in a certain environment, then pigs would also. Curtis (1983) asserts that pigs may be more or less sensi— tive when under certain stressors than are humans. When pigs are penned together after weaning, they develop a dominance order. Animal grouped in high-density situations tend to violate the personal space of other mem- bers, and a dominant order will be developed at the begin- ning. Some animals adopt a dominant behavior and the others a subordinate posture. After grouping, the typical pattern is fighting, manifested by ear biting and head confronta- tion which results in a social hierarchy (Pond and Maner,- 1984; Fritschen, 1981). Curtis (1981) states that the 13 resulting social stability achieved immediately after grouping has a clear advantage because energy is not fur- ther spent in fighting and so damage is minimized. Thus the dominance order tends to decrease social tension in the group to a minimum (Curtis, 1983). The fights that result have little direct effect on growth. Although they can affect the animal performance indirectly, reducing disease resistance or causing injury that can reduce growth (Curtis, 1983). For that reason, pigs should be mixed in a pen that is new to all; therefore eliminating the possibility that they may become extremely aggressive against intruders on their territory (Curtis, 1981). 2.4 Variability of Flow Rate on Frequent Watering Water flow through a pipe depends directly on head loss produced between the pump and waterers; therefore the flow rate decreases as the head loss in a pipe is increased. Variability of the flow rate is a function of the pressure difference along the pipe plus the resistance that the valve presents to flow. In systems providing frequent wat- ering, variability of the flow rate is an important factor on assuring a desired water supply. Olsson and Andersson (1985) conducted a study on grow- ing-finishing pigs and reported that lower‘ flow rates result in water release time becoming too long for the ani- mals; therefore, they tired before they had satisfied their 14 water requirements. They found that there is always a loss in water pressure from the pump to the waterers, so that the flow rate changes with the water pressure. Their results showed that the valves released about 1.35 and 2.85 l/min at 50 and 230 KPa water pressure, respectively. How- ever, the head losses in the pipeline decreased the flow rate to 0.07 l/min. According to Olsson (1983), the distri- bution system and nipple should be well designed in order to avoid high head loss in the pipeline that may affect the water capacity of the nipple and the water release time. He reported that water flow rates of nipple waterers varied significantly with design and manufacturer. In addition, partial plugging reduces the flow rate provided to the ani- mals. Partial plugging is often difficult to detect and can result in reduced water consumption, feed intake and weight gain as noted by Nienaber and Hahn (1984). Schulte et al. (1988), testing several nipple waterers commonly used in swine nurseries, found that they vary widely in flow rate and that some designs should have pressure regu- lators and flow restrictors. Water flow rate, Q, is a function of the square root of the pressure in the pipeline, P, the square of the nipple diameter, d, and the discharge coefficient, C, which depends upon the nipple’s geometry (Schulte et al., 1988). Q = f(C, d2, P0°5) .............. (l) 15 As the previous function indicates, to meet the water requirements of pigs the water pressure in the distribution pipes needs to be ideal to deliver a sufficient amount of water in a short time (Olsson and Andersson, 1985). As pre- dicted by Equation 1, pressure has a direct effect on flow rates. However, Schulte et al. (1988) reported that various brands of nipple waterers used in swine nurseries operating between 210 to 340 KPa of pressure had little effect on flow rates. 3 METHODOLOGY 3.1 Experimental Facility and Animals Two studies were conducted at the south nursery at Michigan State University Swine Research Center. The nurs- ery unit consisted of a 17x4x2 m room with a partly slotted floor having one row of fourteen pens (Figure 3.1). Room temperature was maintained by the addition of an electrical heater system controlled by a thermostat to warm the air and a hot water pipeline under the floor. Ventilation was controlled by two variable speed fans in a negative pres- sure system. Pigs were weaned at 28 d of age were randomly allotted to treatments based on litter and sex. The variation in initial weight was 8.65 to 8.70 kg for Trial I and 7.85 to 7.92 kg for Trial II. The animals were blocked on weight. In Trial I pigs were tested from September 22 to October 20 of 1987. Trial II was conducted from November 4 to December 2 of 1987. No acclimation period was given to the pigs before trials started. 3.2 Trial I Eight 1.22 x 2.44 m pens were used (Figure 3.2), with 12 pigs allotted per pen. Pigs were supplied water by means 16 17 .Eoot >6ch 9: .5 :03 cooE In Sign \| L... 3.2 too¢ 832m .6301 _ _O_._|_. Loop mcma E ¢¢.NXNN.F #LWZQ C._ meQCLLOmeH “*0 COEDQCwQD N.m’ 054071 \\\\\ Loom \ll Boo com 18 coxcto .V IT E mm; cocoon too: poSSm E ¢¢.N 19 of two commercial EdstromR 10744 nipple waterers. Because weaned pigs make lunging movements while drinking water from the nipple drinker, the waterers were positioned 30.5 cm apart. Two water flow treatments combinations were used, as shown in Table 3.1. Table 3.1 Treatment combinations for Trial I. Pen Number Water Flow, ml/min Weight Class 2 & 4 700 Light 3 a 5 700 Heavy 6 & 8 70 Light 7 & 9 70 Heavy 3.3 Trial II Six pigs were housed in eight 1.22 x 1.22 m pens. Sup- ply of water was provided by one commercial EdstromR 10744 nipple waterer located near the wall. Pens were shortened by moving the gate to the correct position (Figure 3.3). As in Trial I, two treatments combinations, 70 and 700 ml/min water flow, were evaluated by using two pens per treatment as shown in Table 3.2. 3.4 Management The experimental diet consisted of a corn-soybean diet containing 15 percent dried whey. It provided 1.15 percent lysine, 0.8 percent calcium, 0.65 percent phosphorus, 0.3 20 .__ BS is 9:5 E $.32 296 2 $558: .6 8:32:20 Omega: 'ai E mm.— »mj/x \ill .8: 832m \ tmxcto \ill cocoon E Nu; E NNA _ — E $5.0 ll}! ilioifiiizilll .i- m 21 Table 3.2 Treatment combinations for Trial II. Pen Number Water Flow, ml/min Weight Class 2 & 4 700 Heavy 3 & 5 700 Light 6 & 8 70 Heavy 7 & 9 70 Light ppm selenium, 30000 IU/ton vitamin E, 25 percent NaCl and ASP-250 or CSP-250. At weaning, nipples in all the pens were allowed to drip for four hours in order to familiarize pigs with nipple waterers placement. Nipple drinkers were mounted at 5 cm above the pig’s shoulder height and directed at a 45° downward slope from horizontal. Water flow rates from nipples and pressure were meas- ured weekly using a stopwatch and graduated cylinder. Water flow rate measurements having a variance of greater than 2 percent were repeated and adjusted as necessary to meet the rates specified in the treatments. Water pressure was meas- ured by a water pressure gage installed in the waterline where the water pipe entered the room and at the last pen. Observation of pigs contacting drinking nipples was conducted weekly on the day prior to weighing the pigs using one pen per treatment combination. Duration of time' that pigs made contact with nipple was recorded in minutes simultaneously for all pens under observation. Measurements lasted for four hours and were conducted from 7:00 to 11:00 22 a.m., when pigs are more actives. Nursery room temperature was registered daily in the morning and afternoon. Measurements were taken at pig height, 0.5 m above floor, at 3 locations in the room. Mortality rate of pigs was 2.1 percent in the first trial. One pig died within the first week of the exper- iment, so it was replaced immediately with a pig of similar size. Another died after the first week, therefore the pen size was decreased by the quantitative amount. On the sec- ond trial, mortality was 4.2 percent. Two pigs died in the first week, so they were replaced by others of similar weight. 3.5 Determination of Water Flow Rate and Pressure In order to determine variability of flow rate as related to pressure in the pipeline, it was necessary to conduct an experiment in the laboratory. It consisted of a tank filled with water which was connected to an air pump. This assured a wide range of constant pressure in the sys- tem (Figure 3.4). The flow rate, Q, was measured directly by collecting the volume of water in a cylinder and record- ing the time elapsed. According to Equation 1, the water flow rate is propor- tional to the square of the nipple diameter and the square root of the pressure. A more generalized expression to define Equation 1 is possible by introducing the contracted area of the waterer, A, and the acceleration of gravity, g: 23 Volve . \ Air 1X] ‘ .__. * Air pump Water ‘ ' Bourdon gage 3 m Pipe 1/8 In. /— Nipple l Figure 3.4 Experimental equipment to-mecsure water Flow and pressure. 24 Q = c* A* v = c* A* (2g* P)°-5 ......... (2) Therefore, the flow rate will depend upon the square root of the pressure, P, and the discharge coefficient, C. In turn, the discharge coefficient will vary with the setting of the nipple’s retainer selected. The flow rate from the nipple was measured at pressure ranging from 34.5 to 400 KPa. Pressure was controlled by manually adjusting a valve located between the air pump and the tank (Figure 3.4). The water level was constant during the experiment. The nipples had a restrictor screw that allowed the water discharge to be adjusted. Three settings were selected which adjusted the water discharge to low, high and intermediate rates. 3.6 Statistics Results shown in tables and figures are expressed as mean values and standard error. Analysis of variance tables (see Appendices) were calculated using split-plot test with repeated measurements for comparison of treatment means when time was considered (Gill, 1986). The t-test was used to estimate the significance of the difference between two group means. SAS (Statistical Analysis System) computer program was employed to obtain all statistic analysis. 4 RESULTS 4.1 Trial I During the first trial, the ambient outside air temper- ature averaged 12°C and fluctuated between 4 and 19°C. The relative humidity of the outside air varied from 49 to 93 percent with an average of 71 percent. The room temperature was maintained between 25 and 27°C. Performance data for Trial I is summarized in Table 4.1. The means for initial and final weight were not stat- istically different. For daily gain, feed intake and feed to gain ratio, there was no significant difference between treatments (P<0.182). The total water intake decreased as water flow rate .decreased (P<0.002), and there was a decrease in the water to feed ratio at 70 ml/min water flow rate (P<0.011). Effect of water flow rate on weekly performance of pigs is presented in Table 4.2. Both final and average daily gain were similar for pigs between treatments. Daily feed intake for individual pigs demonstrated no differences between treatments during week 1, 2 and 3 after weaning. Similarly, feed to gain ratio indicated no difference between treatments during week 1, 2 and 3 after weaning. However, daily gain and feed intake significantly decreased 25 26 Table 4.1 Effect of water flow rate on overall performance of nursery pigs (Trial I). Flow Rate, ml/min Itema 700 70 SEMb Pr>F Initial weight, kg/pig 8.70 8.65 0.25 0.998 Final weight, kg/pig 18.11 16.45 0.41 0.081 Avg. Daily gain, kg/pig 0.34 0.28 0.01 0.073 Daily feed intake, kg/pig 0.67 0.61 0.02 0.356 Feedeain ratio 1.97 2.18 0.03 0.182 Total water intake, l/pig 80.08 33.18 0.84 0.002 Water:Feed ratio 4.27 1.94 0.35 0.011 a Data based on average of 2 pens: trial length was 28 d; 12 pigs/pen, 2 drinkers/pen. b Standard error of the means. and feed conversion statistically worsened for those pigs receiving the 70 ml/min water flow rate during wk 4 after weaning. Effect of water flow rates on drinker contact, water intake per pig and water to feed ratio is presented in Table 4.3. There was a significantly reduced drinker con- tact at 700 ml/min water flow rate during each week of the experiment. On the other hand, water intake increased at 700 ml/min during in all weeks of the trial. The trend for both treatments was to increase water intake from wk 1 to 3 and then decrease in wk 4. Water to feed ratio was larger for those pigs receiving the 700 ml/min water flow rate, however this ratio was not statistically different during wks 2 and 3. The largest difference occurred in wk 4 after 27 Table 4.2 Weekly effect of water flow on mean weight, daily gain, feed intake and feed:gain ratio (Trial I). Treatment, ml/min Item 700 70 Pr>F Mean Weight, kg/pig Wk 0 8.65 8.63 0.989 Wk 1 10.05 9.69 0.489 Wk 2 11.89 11.31 0.484 Wk 3 15.72 14.67 0.221 Wk 4 18.12 16.45 0.081 *SEDT = 0.38 +SEDW = 0.28 Avg. Daily Gain, kg/pig Wk 1 0.20 0.15 0.307 Wk 2 0.26 0.24 0.423 Wk 3 0.55 0.49 0.250 Wk 4 0.34 0.25 0.037 *SEDT = 0.04 +SEDW = 0.03 Avg. Daily Feed Intake, kg/pig Wk 1 0.24 0.22 0.841 Wk 2 0.50 0.48 0.729 Wk 3 0.87 0.83 0.640 Wk 4 1.06 0.90 0.037 *SEDT = 0.89 +SEDW = 0.65 Feed:Gain Ratio Wk 1 1.21 1.46 0.464 Wk 2 1.94 2.09 0.563 Wk 3 1.58 1.75 0.259 Wk 4 3.10 3.68 0.038 *SEDT = 0.31 +SEDw = 0.26 *SEDT is the standard error of differences between treatments for the same week. +SEDw is the standard error of differences for the same treatment. between weeks 28 Table 4.3 Weekly effect of water flow on drinker contact, water intake and water:feed ratio (Trial I). Treatment, ml/min Item 700 70 Pr>F Drinker contact, min/d Wk 1 38.40 125.04 0.037 Wk 2 42.96 165.36 0.035 Wk 3 58.56 223.44 0.018 Wk 4 48.24 200.16 0.020 *SEDT = 0.96 +880w = 0.31 Water intake per pig, l/d Wk 1 2.27 0.96 0.003 Wk 2 2.53 1.03 0.002 Wk 3 3.74 1.45 0.001 Wk 4 2.90 1.30 0.002 *SEDT = 0.21 +SEDw = 0.19 Water:Feed ratio Wk 1 9.46 4.36 0.042 Wk 2 5.06 2.15 0.099 Wk 3 4.29 1.75 0.154 Wk 4 2.74 1.44 0.010 *SEDT = 1.26 +880w = 1.28 *SEDT is the standard error of differences between treatments for the same week. +SEDw is the standard error of differences between weeks for the same treatment. 29 weaning (P<0.010). Variability analysis of overall daily gain revealed no difference between treatments at 5 percent level of confi— dence. 4.2 Trial II In the second trial, the outside temperature averaged 4°C and fluctuated between -7 and 14°C. The relative humidity ranged between 55 and 96 percent, averaging 76 percent. The inside room temperature fluctuated between 26 and 27°C. Performance of nursery pigs are presented in Table 4.4. There was no effect of water flow rate on final weight, daily gain, daily feed intake or feed to gain ratio (P<0.05). Total water intake per pig decreased by half for pigs receiving 70 ml/min water flow rate (P<0.001). Water to feed ratio also decreased with decreased water flow rate (P<0.007). Effect of treatments on weekly performance of nursery pigs are shown in Table 4.5. Neither weekly mean weight nor average daily gain presented significant differences between treatments during the 4 wks of the experiment. Average daily feed intake was affected by the lower water flow rate during wk 4 (P<0.066). On the contrary, feed to gain ratio was not affected by reduced water flow rate at any time. The effect of water flow rate on drinker contact, water 30 Table 4.4 Effect of water flow rate on overall performance of nursery pigs (Trial II). Flow Rate, ml/min Itema 700 70 SEMb Pr>F Initial weight, kg/pig 7.85 ’ 7.93 0.20 0.998 Final weight, kg/pig 20.99 21.50 0.50 0.784 Avg. Daily gain, kg/pig 0.47 0.49 0.01 0.582 Daily feed intake, kg/pig 0.98 0.95 0.02 0.378 Feed:Gain ratio 2.10 1.94 0.02 0.277 Total water intake, l/pig 62.16 25.20 0.65 0.001 Water:Feed ratio 2.26 0.95 0.11 0.007 a Data based on average of 2 pens: trial length was 28 d; 6 pigs/pen, 1 drinker/pen. b Standard error of the means. intake per pig and water to feed ratio is presented in Table 4.6. There was a significant increase in drinker con— tact when water flow rate was reduced (P<0.004). Water intake was less at 70 ml/min than at 700 ml/min water flow rate. Finally, water to feed ratio increased (P<0.024) at 700 ml/min water flow rate. 4.3 Behavioral Response of Nursery Pigs After grouping both experiments, visual observations revealed that newly weaned pigs followed the typical ten- dency to fight which was demonstrated by ear biting during the first 2 days after weaning. Afterward a social stabil- ity within pens was achieved quickly. 31 Table 4.5 Weekly effect of water flow on mean weight, daily gain, feed intake and feed:gain ratio (Trial II). Treatment, ml/min Item 700 70 Pr>F Mean Weight, kg/pig Wk 0 7.85 7.93 0.995 Wk 1 10.43 10.41 0.997 Wk 2 12.49 12.84 0.816 Wk 3 16.80 17.25 0.795 Wk 4 21.00 21.50 0.784 *SEDT = 0.84 +SEDW = 0.38 Avg. Daily Gain, kg/pig Wk 1 0.37 0.35 0.921 Wk 2 0.29 0.35 0.440 Wk 3 0.62 0.63 0.924 Wk 4 0.60 0.61 0.983 *SEDT = 0.06 +880w = 0.06 Avg. Daily Feed Intake, kg/pig Wk 1 0.46 0.44 0.886 Wk 2 0.74 0.75 0.998 Wk 3 1.14 1.17 0.709 Wk 4 1.58 1.43 0.066 *SEDT = 0.41 +SEDw = 0.28 Feed:Gain Ratio Wk 1 1.27 1.25 0.987 Wk 2 2.55 2.16 0.458 Wk 3 1.86 1.86 0.999 Wk 4 2.73 2.37 0.379 *SEDT = 0.32 +SEDw = 0.36 *SEDT is the standard error of differences between treatments for the same week. ' +SEDw is the standard error of differences between weeks for the same treatment. Table 32 4.6 Weekly effect of water flow rate on drinker contact, water intake and water:feed ratio (Trial II). Treatment, ml/min Item 700 70 Pr>F Drinker contact, min/d Wk 1 16.80 60.48 0.004 Wk 2 21.12 64.08 0.004 Wk 3 17.52 99.84 0.001 Wk 4 19.20 83.28 0.002 *SEDT = 0.27 +SEDw = 0.19 Water intake per pig, l/d Wk 1 2.13 0.66 0.001 Wk 2 2.70 0.78 0.001 Wk 3 1.77 1.16 0.001 Wk 4 2.28 0.98 0.001 *SEDT = 0.13 +SEDw = 0.14 Water:Feed ratio Wk 1 4.63 1.50 0.001 Wk 2 3.65 1.04 0.001 Wk 3 1.55 ‘0.99 0.024 Wk 4 1.44 0.87 0.001 *SEDT = 0.05 +SEDw = 0.05 *SEDT is the standard error of difference between treat- ments for the same week. +SEDW for the same treatment. is the standard error of difference between weeks 33 No observation of the pigs trying to cool themselves through water wastage or resting grouped was noted, indica- ting adequate temperature control. It was observed that in both trials pigs spent more time drinking at the lower water flow rate treatment (70 ml/min). The higher flow rate treatment (700 ml/min) demon- strated that pigs significantly wasted water during drink- ing, whereas the lower treatment produced insignificant wastage. However, in Trial I the pigs comparatively wasted more water than Trial II. This was due to a higher competi- tion at drinking times. Apparently none of the pigs became tired because of prolonged drinking times, yet heavier pigs possibly became frustrated to the point of affecting per- formance. 4.4 Pressure and Water Flow Rate Variability Variability of flow rates and measurements of pressure in the distribution pipeline for Trial I are presented in Table 4.7. Maximum water flow rates occurred during wk 3 after weaning, whereas minimum rates occurred in wk 1. This feature coincided with the fact that pressure in the dis- tribution pipe was maximum in week 3 and minimum in week 1. It showed a direct correlation between water flow rates and hydraulic pressure in the system, which is supported by theory (Streeter and Wylie, 1979). Based on the square root of pressure as indicated in 34 Table 4.7 Weekly flow rates and pressure for Trial I. Treatment, ml/min Pressure, KPaa Week 700 70 A B PA-PB 1 705 71 207 193 14 2 722 76 276 261 15 3 770 78 283 271 12 4 727 78 252 241 11 Mean 731 76 255 236 13 a A indicates pressure measured at pipe entering room and B at the last pen location (1 atmosphere = 101.325 KPa). Equation 2, variability of pressure was determined to be: (283)0-5 16.8 (207)0-5 = 14.4 It indicated that there was a 14.3 percent increase in pressure from 207 to 283 KPa. Table 4.8 reports variability of water flow rate and pressure for Trial II. Maximum water flow rate and pressure were recorded in wk 2 after weaning, whereas minimum values were measured in wk 3. Based on Equation 2, there was a 20.4 percent increase in pressure from 179 to 283 KPa dur- ing the experiment. The effect of pressure on flow rate from the— nipple waterer is illustrated in Figure 4.1, where data was exper- imentally collected for a range of 35 to 400 KPa. The 35 2400 q ~ e—o Low setting i H Intermediate setting 2000‘ H High setting A 4 .E « E ., > 1600- E a: V i ‘i . 0: 1200-i it. 'i < 1 m «l .1 3 800 i O _J 'i LI- . 400- 0 1 r I 7F fi F r 1 ‘ T ' t ' I 0 100 200 300 400 PRESSURE, P (KPa) Figure 4.15 Effect of pressure on water flow rate. 36 Table 4.8 Weekly flow rates and pressure for Trial II. Treatment, ml/min Pressure, KPaer Week 700 70 A B PA-PB 1 700 70 221 213 8 2 774 73 283 272 11 3 604 70 179 166 13 4 709 70 269 255 14 Mean 697 71 238 226 12 a A indicates pressure measured at pipe entering room and B at the last pen location (1 atmosphere = 101.325 KPa). experiment was replicated three times. In general, pressure had a strong influence on water flow rate in the 35 to 140 KPa but a relatively small effect at pressures higher than 140 KPa. This feature was supported from the values shown in Table 4.7 and 4.8, where there was very good water flow rate control at pressures higher than 140 KPa. At the high setting, changes in the flow rate varied from a minimum of 695 ml/min to a maximum of 2050 ml/min in the 35 to 400 KPa range. At the low set- ting, flow rate varied from 241 to 564 ml/min in the same range of pressure. 5 DISCUSSION In Trial I, water flow rate of 70 ml/min indicated a trend for the overall average daily gain to be depressed. Also, weekly performance revealed that average daily gain, average daily feed intake and feed conversion for wk 4 (56 days of age) were significantly affected at 70 ml/min and 25-27°C room temperature with 12 pigs per pen. In Trial II, there were no differences on pig performance, even though the average daily feed intake tended to be lower (P<0.066) during wk 4, while numerically the feed conversion was bet- ter. These findings were similar to those of Nienaber and Hahn (1984), who worked with 100, 350, 600, 850 and 1100 ml/min. Moreover, the results for both trials were similar to those found by Carlson and Peo (1982), who found that there was no difference in feed to gain ratio at flow rates higher than 1100 ml/min. Water intake volumes measured in Trial I and II were lower than the results obtained from a similar experiment conducted by Nienaber and Hahn (1984), who worked with 2 pigs/pen housed at 35°C. This difference may be due to the fact that the pigs were maintained at a lower room tempera- ture and there was a higher density of pigs per pen, as also noted by Nienaber and Hahn (1987). It confirms that 37 38 the higher the ambient temperature the higher the water consumption (Baxter, 1984). The results of water intake shown in Table 4.1 and 4.4, probably suggest that nursery pigs usually drink more water than they really need, as previously noted by Yang et al. (1981). Water to feed ratio of 0.95:1 to 4.27:1 had no effect on final weight and total gain per pig. A similar result was reported by Castle and Castle (1957) and Holme and Robinson (1965), who found that variations from 1.5:1 to 3.75:1 had little effect on overall performance. This dif- ference in the water supplied demonstrated that nursery pigs can tolerate a wide range of water to feed ratios (Carlson and Peo, 1982; Nienaber and Hahn, 1984). In Trial I, rate of gain decreased at 70 ml/min water flow rate only in wk 4 after weaning, so worsening feed conversion. This is explained by the lower feed intake in that period. A similar tendency was also observed by Brooks et al. (1984) in the first days after weaning. Also, possi- bly the heavier pigs spent more time drinking during wk 4, yet may have been frustrated to the point of affecting per- formance. The importance of the restricted water flow rate is evident when pigs must weight 25 kg liveweight before leav- ing the nursery unit. In that case, 58 days are required for those pigs receiving 70 ml/min, as compared to-48 days needed for pigs at 700 ml/min water flow rate. The extra 10 days to reach the desired 25 kg for market or movement to 39 growing facilities will mean crowding of pigs in the nurs— ery units, selling pigs at a lighter weight, or moving those animals into a grower environment that the smaller pigs may not tolerate well. In Trial I, the decrease in water intake at the 70 ml/min treatment was supported by the fact that the pigs spent four times as much time drinking than at 700 ml/min treatment (Table 4.3). In Trial II significant differences in time spent drinking indicated that pigs also increased their weekly water intake at increased water flow rate (Table 4.6). The time spent drinking in Trial I was double that of Trial II, indicating that there was a greater competition for water in pens with 12 pigs having two drinkers (Trial I) than 6 pigs/pen and one drinker (Trial II). The stronger competition in pens containing 12 pigs was correlated with a higher water wastage when compared to pens containing 6 pigs in Trial II. Although, variability analysis performed for overall daily gain in Trial I revealed no difference between treatments (P>0.05). Compe- tition was also evident from the higher growth rate mean values obtained in Trial II as compared to Trial I. The results indicated that smaller groups of pigs have better performance than larger groups, as also noted by Brent et al. (1975), due to less competition for water. A similar pattern was found by Olsson (1983a), who evaluated. nipple. waterers for fattening pigs. In both trials water intake decreased as water flow 40 rate decreased, whereas rate of gain, feed intake and feed conversion remained unaffected. This pattern was also reported by Olsson (1983b) and Nienaber and Hahn (1984). Because of the possibility that nursery pigs do not neces— sarily have a large water intake and may drink. less water than needed without affecting performance, further studies are necessary to measure wastage or even urine output to differentiate between water intake and wastage. This decrease in water wastage and a longer drinker contact at 70 ml/min for both trials suggests that young pigs are able to adapt to a wide range of water flow rates, a characteristic previously noted by Nienaber and Hahn (1984). As pigs increase in weight and the temperature rises, water flow rate becomes important (Nienaber and Hahn, 1987). This may explain the differences in growth rate, feed intake and feed to gain ratio in week 4 after weaning, as noted in Trial I (Table 4.2). The 70 ml/min water flow rate for pigs at to 16 kg liveweight and 26°C room tempera- ture tended to be the minimum acceptable water flow rate. This suggests that as temperature rises and pigs are heavier, water flow rate should be increased above 70 ml/min. This indicated that there are limits to the adapta- tion of nursery pigs to restrictions of water flow rates, as also stated by Nienaber and Hahn (1984). The higher pig performance results found in Trial II was due to the greater competition in pens containing 12 41 pigs and 2 drinkers, associated with a visual higher wast- age in Trial I. Further studies are recommended to measure water wastage for pigs receiving water flow rate above 70 ml/min. Also, because of the possibility of partial plug- ging in the nipples, more studies are recommended to study the response of the waterer at low pressures in swine nurs- ery facilities. As indicated in Table 4.7 and 4.8, there was very good flow rate control. The distribution system was dimensioned so that the 70 and 700 ml/min treatments could be applied very precisely at a water pressure of 179 and 283 KPa. The results were supported with data obtained from the labora- tory (Figure 4.1), where the pressure had little effect on water flow rate of the nipple waterer in the 140 to 400 KPa range. Schulte et al. (1988) found a similar response in the range of 200 to 500 KPa. This proved that the nipple waterer could be used widely in swine nurseries without pressure regulators in the pipeline. 6 CONCLUSIONS 1. Providing a water flow rate of 70 ml/min to 12 pigs per pen weaned at 28 days and housed at 26°C room temperature resulted in a reduction in the average daily gain, average daily feed intake and feed conversion during wk 4 after weaning. 2. Overall daily gain tended to be depressed for pigs receiving the lower water flow rate (P<0.073). This depressed tendency has important implications on pig's flow through the nursery, growing and finishing phases. 3. Observation of performance during week 4 revealed that the 70 ml/min water flow rate approaches the minimum requirement for 12 pigs per pen at 16 to 18 kg live weight and 26°C room temperature. This suggested that there are limits to the adaptation of nursery-age pigs to restricted water flow rates. Consequently, as temperature rises and pigs are heavier, water flow rates should be provided above 70 ml/min. 4. The variability of the water flow rate studied demon— strated that if the water supply system provides pressures 42 43 at a range of 140 to 400 KPa, the EdstromR waterer(1) will repeatedly supply either 70 or 700 ml/min water flow rate without pressure regulators in the pipeline. (1) It does not imply endorsement nor prejudice for or against this product, or for or against products not mentioned. APPENDICES BIBLIOGRAPHY Agricultural Research Council. 1981. The nutrient require- ment of pigs: technical review.Commonwealth Agricultural Bureaux, Farnham Royal, England. Baxter, Seaton. 1984. Intensive pig production: environmen- tal management and design. Granada Publishing Ltd., London. Brent, G., D. Hovell, R.F. Ridgeon and W.J. Smith. 1975. Early weaning of pigs. Farming Press Limited, Fenton House, Suffolk. Brooks, P.H., S.J. Russell and J.L Carpenter. 1984. Water intake of weaned piglets from three to seven weeks old. The Veterinary Record 115, 513-515. Carlson, R.L. and E.R. Peo. 1982. Nipple waterer position -up or down? Nebraska Swine Report, EC 82-219, University of Nebraska, Lincoln. Church, D.C. 1984. Livestock feeds and feeding. O & B Books Inc., Englewood Cliffs, New Jersey. Curtis, Stanley E. 1981. The environment in swine housing. Extension Bulletin E-1284, Michigan State University, East Lansing. Curtis, Stanley E. 1983. Environmental management in animal agriculture. The Iowa State University Press, Ames. Ensminger, M.E. 1962. Animal science. The Interstate Print- ers & Publishers Inc., Danville, Illinois. Ensminger, M.E. 1970. Swine science. The Interstate Print- ers & Publishers Inc., Danville, Illinois. Fritschen, R.D. 1981. Space requirements for swine. Exten- sion Bulletin E-1283, Michigan State University, East Lans— ing. Gillespie, James R. 1981. Modern livestock and poultry production. Delmar Publishers, Albany, New York. Gill, John L. 1986. Repeated measurement: sensitive tests 44 45 for experiments with few animals. Journal of Animal Science 63: 943-954. Holme, D.W. and R.L. Robinson. 1965. A study of water allowances for the bacon pig. Animal Production 7: 377-383. Leman, A.D., Barbara Straw, Robert D. Glock, William L. Mengeling, R.H. Penny and Erwin School. 1986. Diseases of swine. The Iowa State University Press, Ames. Mount, L.E., C.W. Holmes, W.H. Close, S.R. Morrison and I.B. Start. 1971. A note on the consumption of water by the growing pig at several environmental temperatures and lev- els of feeding. Animal Production 13: 561-563. Neter, J., W. Wasserman and M.H. Kutner. 1985. Applied lin- ear statistical methods. Richard D. Irwin, Inc., Homewood, Illinois. Nienaber, J.A. and G.L. Hahn. 1984. Effects of water flow restriction and environmental factors on performance of nursery-age pigs. Journal of Animal Science 59: 1423-1429. Nienaber, J.A. and G.L. Hahn. 1987. Feeding behavior and energetics of growing-finishing swine as influenced by environmental temperature. ASAE Paper No. 87-4512, St. Joseph, Michigan. Olsson, Ove. 1983a. Evaluation of bite drinkers for fatten- ing pigs. Transactions of the ASAE 26: 1495-1498. Olsson, Ove. 1983b. The ability of the pig to use a nose valve drinking system. Acta Agriculture Scandinavica 33: 161-169. Olsson,_ Ove and T. Andersson. 1985. Biometric consider- ations when designing a valve system for growing-finishing pigs. Acta Agriculture Scandinavica 35: 55-66. Pond, W.G. and J.H. Maner. 1984. Swine production and nutrition. AVI Publishing Co., Westport, Connecticut. Schulte, D.D., G.R. Bodman and M.J. Milanuk. 1988. Effect of pressure on flow rates from nipple waterers for swine nurseries. ASAE Paper No. 88-4029, St. Joseph, Michigan. Streeter, V.L. and E.B. Wylie. 1979. Fluid mechanics. McGraw-Hill, Inc., New York. Yang, T.S., B. Howard and W.V. MacFarlane. 1981. Effects of food on drinking behavior of growing pigs. Applied Animal Ethology 7: 259-270. ' Appendix A1. 46 Repeated measures weekly growth rate (Trial I). analysis of variance for Source df SS MS F Pr>F Treatment (T) 1 5.3949 5.3949 5.48 0.0793 Block (B) 1 63.3277 63.3277 64.34 0.0013 T*B 1 0.2641 0.2641 0.27 0.6318 Error 1 4 3.9368 0.9842 Period (P) 3 421.8967 105.4742 481.23 0.0001 P*T , 3 3.2917 0.8229 3.83 0.0227 P*B 3 2.0419 0.5105 2.38 0.0954 P*T*B 3 0.1885 0.0471 0.22 0.9237 Error 2 12 3.4354 0.2147 Appendix A2. Repeated measures analysis of variance for average daily gain (Trial I). Source df SS MS F Pr>F Treatment (T) 1 0.0228 0.0228 3.84 0.1217 Block (B) 1 0.0122 0.0122 2.06 0.2244 T*B 1 0.0003 0.0003 0.04 0.8432 Error 1 4 0.0238 0.0059 Period (P) 3 0.5252 0.1751 111.52 0.0001 P*T 3 0.0033 0.0011 0.70 0.5705 P*B 3 0.0186 0.0062 3.98 0.0352 P*T*B 3 0.0014 0.0005 0.29 0.8302 Error 2 12 0.0187 0.0016 Appendix A3. Repeated measures weekly feed intake (Trial I). analysis of variance for Source df 88 MS F Pr>P Treatment (T) 1 18.868 18.868 1.21 0.3326 Block (B) 1 28.055 28.055 1.96 0.2337 T*B 1 0.248 0.248 0.02 0.9056 Error 1 4 62.234 15.559 Period (P) 3 1628.149 542.716 156.13 0.0001 P*T 3 18.454 6.151 1.77 0.2064 P*B 3 12.979 4.326 1.24 0.3368 P*T*B 3 1.859 0.620 0.18 0.9090 Error 2 12 41.712 3.476 - 47 Appendix A4. Repeated measures analysis of variance for feed:gain ratio (Trial I). Source df SS MS F Pr>P Treatment (T) 1 0.6641 0.6641 1.83 0.2473 Block (B) 1 0.1365 0.1365 0.38 0.5726 T*B 1 0.0058 0.0058 0.02 0.9056 Error 1 4 1.4498 0.3624 Period (P) 3 19.5609 6.5203 47.07 0.0001 P*T 3 0.2368 0.0789 0.57 0.6454 P*B 3 0.7810 0.2603 1.88 0.1869 P*T*B 3 0.2092 0.0697 0.50 0.6870 Error 2 12 1.6621 0.1385 Appendix A5. Repeated measures drinker contact (Trial I). analysis of variance for Source df SS MS F Pr>P Treatment (T) 1 2881.992 2881.992 35.17 0.1063 Block (B) 1 256.344 256.344 3.13 0.3276 Error 1 1 81.936 81.936 Period (P) 3 326.832 108.936 17.24 0.0214 P*T 3 151.632 50.544 8.00 0.0608 Error 2 6 13.363 2.227 Appendix A6. Repeated measures analysis of variance for weekly water intake (Trial I). Source df SS MS F Pr>P Treatment (T) 1 22.445 22.445 341.76 0.0001 Block (B) 1 3.125 3.125 47.58 0.0023 T*B 1 0.151 0.151 2.30 0.2037 Error 1 4 0.263 0.066 Period (P) 3 4.547 1.516 42.46 0.0001 P*T 3 1.095 0.365 10.23 0.0013 P*B 3 0.557 0.186 5.20 0.0157 P*T*B 3 0.447 0.149 4.18 0.0306 Error 2 12 0.428 0.036 Appendix A7. 48 Repeated measures water:feed ratio (Trial I). analysis of variance for Source df SS MS F Pr>P Treatment (T) 1 1.415 1.415 24.10 0.0081 Block (B) 1 0.009 0.009 0.15 0.7193 T*B 1 0.041 0.041 0.70 0.4492 Error 1 4 0.235 0.059 Period (P) 3 2.191 0.730 21.25 0.0001 P*T 3 0.272 0.091 2.64 0.0970 P*B 3 0.021 0.007 0.19 0.9007 P*T*B 3 0.007 0.002 0.07 0.9766 Error 2 12 0.412 0.034 Appendix A8. Repeated measures analysis of variance for weekly growth rate (Trial II). Source df SS MS F Pr>P Treatment (T) 1 0.0020 0.0020 0.00 0.9877 Block (B) 1 39.5723 39.5723 5.30 0.0827 T*B 1 8.4916 8.4916 1.14 0.3463 Error 1 4 29.8602 7.4651 Period (P) 3 769.4007 192.3501 540.13 0.0001 P*T 3 0.2995 0.0749 0.21 0.9289 P*B 3 3.7086 0.9271 2.60 0.0753 P*T*B 3 2.1955 0.5489 1.54 0.2378 Error 2 12 5.6979 0.3561 Appendix A9. Repeated measures average daily gain (Trial II). analysis of variance for Source df 88 MS F Pr>P Treatment (T) 1 0.0017 0.0017 0.52 0.5106 Block (B) 1 0.0571 0.0571 17.67 0.0137 T*B 1 0.0047 0.0047 1.47 0.2920 Error 1 4 0.0129 0.0032 Period (P) 3 0.6038 0.2013 24.33 0.0001 P*T 3 0.0050 0.0017 0.20 0.8946 P*B 3 0.0199 0.0066 0.80 ‘0.5172 P*T*B 3 0.0060 0.0020 0.24 0.8662 Error 2 12 0.0993 0.0083 49 Appendix A10. Repeated measures analysis of variance for weely feed intake (Trial II). Source df SS MS F Pr>P Treatment (T) 1 2.583 2.583 0.36 0.5823 Block (B) 1 42.950 42.950 5.94 0.0715 T*B 1 1.167 1.167 0.16 0.7084 Error 1 4 28.932 7.233 Period (P) 3 1501.529 500.510 396.67 0.0001 P*T 3 11.249 3.750 2.97 0.0744 P*B 3 10.115 3.372 2.67 0.0947 P*T*B 3 2.296 0.765 0.61 0.6234 Error 2 12 15.141 1.262 Appendix A11. feed:gain ratio (Trial II). Repeated measures analysis of variance for Source df SS MS F Pr>P Treatment (T) 1 0.5940 0.5940 13.73 0.0207 Block (B) 1 0.5408 0.5408 12.50 0.0241 T*B 1 0.2775 0.2775 6.42 0.0645 Error 1 4 0.1730 0.0432 Period (P) 3 9.5584 3.1861 12.35 0.0006 P*T 3 0.7061 0.2354 0.91 0.4640 P*B 3 1.2118 0.4039 1.57 0.2488 P*T*B 3 0.6008 0.2003 0.78 0.5294 Error 2 '12 3.0956 0.2579 Appendix A12. Repeated measures analysis of variance for drinker contact (Trial II). Source df SS MS F Pr>P Treatment (T) 1 563.616 563.616 120.20 0.0579 Block (B) 1 4.553 4.553 0.97 0.5047 Error 1 1 4.689 4.689 Period (P) 3 40.464 13.488 10.95 0.0400 P*T 3 44.256 14.752 11.97 0.0355 Error 2 6 3.703 0.617 50 Appendix A13. Repeated measures analysis of variance for weekly water intake (Trial II). Source df SS MS F Pr>P Treatment (T) 1 14.032 14.032 3023.68 0.0001 Block (B) 1 3.153 3.156 680.15 0.0001 T*B 1 3.032 3.032 653.35 0.0001 Error 1 4 0.019 0.005 Period (P) 3 0.596 0.199 9.72 0.0016 P*T 3 1.761 0.587 28.72 0.0001 P*B 3 1.691 0.564 27.57 0.0001 P*T*B 3 1.516 0.505 24.73 0.0001 Error 2 12 0.245 0.020 Appendix A14. Repeated measures analysis of variance for water:feed (Trial II). Source df SS MS F Pr>P Treatment (T) 1 0.4656 0.4656 156.84 0.0002 Block (B) 1 0.0595 0.0595 20.05 0.0110 T*B 1 0.0882 0.0882 29.71 0.0055 Error 1 4 0.0119 0.0030 Period (P) 3 0.3937 0.1312 53.71 0.0001 P*T 3 0.1785 0.0595 24.34 0.0001 P*B 3 0.0457 0.0152 6.23 0.0085 P*T*B 3 0.0699 0.0233 9.54 0.0017 Error 2 12 0.0293 0.0024 51 Appendix 15. Individual weights for Trial I (pounds). Weekly weights Pen Pig Trt Wk 1 Wk 2 Wk 3 Wk 4 Wk 5 2 122-14 700L 18.50 19.80 21.20 29.00 36.50 2 221-16 700L 17.90 17.80 18.50 19.20 23.10 2 125-26 700L 17.20 18.30 21.50 27.10 32.00 2 126-10 700L 15.50 17.40 18.80 24.80 28.00 2 126-26 700L 16.10 19.10 22.30 29.10 25.00 2 225-11 700L 17.90 20.70 26.20 36.90 39.50 2 H5-lG 700L 13.70 16.40 18.50 21.80 24.40 2 127-1G 700L 18.80 21.60 24.00 29.40 37.00 2 228-1G 700L 18.00 22.60 26.70 35.30 41.50 2 228-10 700L 16.30 20.90 24.30 32.60 37.00 2 Y10-1G 700L 17.00 21.30 24.70 34.10 45.00 2 Y10-3G 700L 16.00 20.30 24.40 31.70 37.00 Totals Pen 2 202.90 236.20 271.10 351.00 406.00 3 122-10 700H 24.80 26.40 31.30 43.50 52.00 3 122-1G 700H 23.70 26.20 28.10 38.30 47.60 3 H4-1G 700H 20.30 23.20 25.90 37.50 46.00 3 221-1G 700K 19.90 22.50 25.10 31.10 32.00 3 225-10 700H 19.70 23.40 28.70 37.10 38.00 3 223-13 700H 21.80 25.90 29.70 37.40 38.60 3 223-12 700H 22.00 25.90 32.60 42.20 52.00 3 223-6G 700H 20.90 25.50 33.00 40.00 41.50 3 224-14 700H 20.10 20.00 26.00 36.40 39.50 3 222-12 700H 20.10 22.70 29.30 36.60 44.80 3 227-2G 700H 21.30 23.40 25.70 36.20 41.00 3 227-4G 700H 20.50 25.00 30.60 41.80 45.00 Totals Pen 3 255.10 290.10 346.00 458.10 518.00 4 225-4G 700L 15.10 20.60 25.70 34.50 40.00 4 225-6G 700L 15.00 18.80 23.00 32.70 34.60 4 226-11 700L 17.90 21.40 26.00 35.90 43.00 4 127-14 700L 17.10 21.50 25.10 33.30 38.00 4 127-26 700L 17.10 21.50 23.40 32.90 39.00 4 223-4G 700L 16.90 20.20 24.00 30.90 36.50 4 223-14 700L 16.30 15.60 26.50 35.20 43.00 4 224-1G 700L 18.30 21.60 24.50 31.30 38.00 4 224-12 700L 13.40 16.70 15.60 20.80 27.00 4 Y10-4G 700L 17.90 19.40 24.00 32.70 38.00 4 124-11 700L 15.90 19.70 21.90 31.20 39.00 4 227-6G 700L 19.20 24.10 27.90 39.50 48.00 Totals Pen 4 200.10 241.10 287.60 390.90 464.10 52 Appendix 15. (Continued) Weekly weights Pen Pig Trt Wk 1 Wk 2 Wk 3 Wk 4 Wk 5 5 122-2G 700H 24.50 27.60 31.00 40.40 51.50 5 122-13 700B 20.90 21.00 22.00 30.70 37.00 5 221-2G 700H (21.00 23.00 27.50 34.60 36.50 5 225-1G 700H 20.30 24.60 31.10 37.60 39.00 5 226-10 700H 23.90 28.30 35.70 45.60 52.00 5 226-26 700H 20.50 23.00 27.90 38.20 45.50 5 127-10 700H 20.00 22.10 28.30 37.30 38.00 5 223-1G 700H 21.60 24.60 28.80 37.90 47.00 5 223-3G 700H 19.90 23.90 28.50 38.20 47.00 5 228-11 700H 19.50 24.70 30.60 40.10 41.00 5 222-13 700B 21.50 26.30 33.20 44.50 54.00 5 227-10 700B 22.80 25.40 28.00 36.30 38.50 Totals Pen 5 256.40 294.50 352.60 461.40 527.00 6 125-4G 70L 14.30 15.00 15.90 18.50 20.50 6 125-3G 70L 17.60 19.20 23.40 30.40 33.50 6 126-11 70L 16.20 18.50 23.60 29.00 29.00 6 126-56 70L 15.80 18.80 22.20 27.00 30.50 6 225-12 70L 18.20 22.90 26.90 35.70 40.00 6 226-46 70L 17.00 19.50 22.50 28.30 32.80 6 H6-2G 70L 18.00 17.00 19.80 24.10 29.00 6 127-15 70L 17.70 20.30 22.40 30.60 35.50 6 228-3G 70L 16.10 19.50 23.40 30.70 32.50 6 Y10-2G 70L 18.80 20.40 24.90 33.60 34.00 6 Y9-7B 70L 14.30 16.20 17.30 23.40 29.00 6 221-13 70L 16.80 18.50 20.40 24.20 28.00 Totals Pen 6 200.80 225.80 262.70 335.50 374.30 7 122-3G 70H 22.50 24.50 29.90 37.80 41.50 7 122-11 70H 23.10 26.90 28.30 38.00 45.00 7 225-2G 70H 20.40 22.60 28.50 34.70 39.50 7 226-12 70H 19.90 21.60 25.90 33.00 38.70 7 226-36 70H 21.20 25.40 30.90 38.60 39.00 7 127-13 70H 18.90 20.50 25.60 32.60 38.00 7 223-10 70H 22.10 26.30 30.30 40.50 47.00 7 223-5G 70H 20.00 21.20 23.50 28.10 33.50 7 224-10 70H 21.50 24.80 27.40 36.40 42.00 7 209-16 70H 24.50 28.70 31.80 42.00 49.00 7 227-3G 70H 20.80 22.50 25.80 35.30 40.00 7 221-15 70H 20.50 22.00 25.30 29.00 ‘33.50 Totals Pen 7 255.40 287.00 333.20 426.00 486.70 53 Appendix 15. (Continued) Weekly weights Pen Pig Trt Wk 1 Wk 2 Wk 3 Wk 4 Wk 5 8 124-10 70L 18.20 22.70 25.60 34.30 36.80 8 225-3G 70L 19.70 25.10 31.00 40.00 44.50 8 H6-3G 70L 14.30 15.00 16.30 17.10 23.50 8 HS-ZG 70L 17.70 19.30 22.00 28.00 28.50 8 127-11 70L 17.40 21.20 22.80 29.20 34.00 8 127-3G 70L 15.90 17.20 20.70 27.40 33.50 8 228-12 70L 16.50 18.40 25.40 36.10 39.00 8 224-2G 70L 16.30 19.70 25.60 34.20 39.50 8 224-36 70L 17.10 20.00 22.60 32.10 41.00 8 124-12 70L 16.10 18.50 20.80 25.20 30.50 8 ZZZ-16 70L 18.10 22.60 28.30 38.80 47.50 8 Y9-6B 70L 13.10 13.60 16.80 23.70 25.20 Totals Pen 8 200.40 233.30 277.90 366.10 423.50 9 125-10 70H 20.70 21.80 26.30 33.60 39.00 9 221-10 70H 19.80 15.20 - - - 9 123-4G 70H 25.00 26.60 31.50 39.10 43.00 9 221-11 70H 18.60 19.80 25.20 32.10 32.50 9 126-1G 70H 20.50 22.70 30.50 39.30 39.00 9 226-16 70H 22.70 25.40 32.40 43.20 40.50 9 223-11 70H 20.80 23.70 26.80 35.40 39.00 9 228-2G 70H 20.30 25.00 30.40 39.10 40.00 9 222-10 70H 22.80 26.20 32.10 45.90 51.50 9 Yll-lG 70H 21.20 21.30 24.90 33.30 38.40 9 122-15 70H 22.90 27.00 36.40 47.50 57.00 9 227-5G 70H 20.80 23.50 25.20 34.50 35.00 Totals Pen 9 256.10 278.20 321.70 423.00 454.90 54 Appendix 16. Individual weights for Trial II (pounds). Weekly weights Pen Pig Trt Wk 1 Wk 2 Wk 3 Wk 4 Wk 5 2 Y12-4 700H 18.00 23.20 28.10 36.00 44.50 2 Y14-4 700H 18.20 23.90 30.00 38.00 43.00 2 130-1 700H 20.40 24.30 29.00 40.50 50.50 2 241-13 700H 19.90 19.90 28.00 40.00 50.50 2 249-2 700H 20.60 28.00 36.50 47.50 58.00 2 248-17 700H 17.20 26.40 34.50 47.00 55.00 Totals Pen 2 114.30 145.70 186.10 249.00 301.50 3 253-11 700L 16.70 20.40 26.00 37.50 46.00 3 246-2 700L 16.20 24.10 30.00 40.00 46.50 3 H8-3 700L 15.50 20.70 24.00 36.00 39.00 3 249-12 700L 15.20 19.30 24.90 37.00 44.50 3 253-12 700L 14.70 21.60 21.60 31.00 36.50 3 251-5 700L 14.40 18.70 22.00 31.00 39.00 Totals Pen 3 92.70 124.80 148.50 212.50 251.50 4 Y14-3 700H 21.10 26.80 33.00 40.00 54.00 4 249-14 700H 20.90 26.50 34.00 40.00 53.00 4 Y12-1 700H 19.20 26.30 31.00 42.00 54.00 4 249-11 700H 18.30 24.90 29.00 40.00 50.00 4 241-12 700H 17.10 24.40 29.00 37.00 50.00 4 249-1 700H 18.40 28.60 35.00 45.00 55.00 Totals Pen 4 115.00 157.50 191.00 244.00 316.00 5 Y13-1 700L 16.50 20.20 22.00 28.50 38.00 5 241-15 700L 16.20 23.50 27.00 36.00 49.00 5 Y12-3 700L 15.80 18.90 19.20 28.00 36.00 5 Y14-1 700L 15.00 19.70 21.00 27.00 35.00 5 241-14 700L 14.90 21.30 24.00 32.00 43.00 5 253-14 700L 14.50 19.90 21.40 31.00 40.00 Totals Pen 5 92.90 123.50 134.60 182.50 241.00 6 248-15 70H 19.70 26.60 31.00 40.00 52.00 6 246-1 70H 19.10 25.70 30.00 40.00 49.00 6 243-2 70H 18.50 21.30 27.00 35.00 45.00 6 251-10 70H 17.00 22.90 27.00 36.00 46.00 6 249-10 70H 20.90 28.30 36.00 45.00 55.00 6 248-1 70H 21.90 24.50 30.00 38.00 50.00 Totals Pen 6 117.10 149.30 181.00 234.00 297.00 55 Appendix 16. (Continued) Weekly weights Pen Pig Trt Wk 1 Wk 2 Wk 3 Wk 4 Wk 5 7 Y13-2 70L 16.10 21.30 25.60 35.00 43.00 7 241-11 70L 16.80 22.60 29.00 39.00 47.00 7 251-3 70L 15.50 22.10 28.50 38.00 47.00 7 246-10 70L 15.40 19.60 26.00 35.50 43.00 7 130-3 70L 14.60 20.00 25.50 33.00 41.00 7 249-11 70L 14.80 22.20 28.00 36.00 46.00 Totals Pen 7 93.20 127.80 162.60 216.50 267.00 8 248-10 70H 20.80 29.40 36.50 49.50 60.00 8 249-2 70H 21.20 27.90 34.50 46.00 55.00 8 243-10 70H 18.80 23.50 28.00 38.00 48.00 8 241-1 70H 19.50 27.20 26.50 45.00 56.00 8 243-3 70H 18.20 23.30 31.00 41.00 50.00 8 252-1 70H 17.10 19.80 34.00 38.00 47.50 Totals Pen 8 115.60 151.10 190.50 257.50 316.50 9 251-12 70L 14.50 20.40 25.50 35.50 45.00 9 242-3 70L 16.30 20.40 24.50 34.50 42.00 9 130-11 70L 16.70 22.40 27.00 36.00 44.00 9 Y14-6 70L 15.80 19.50 22.50 30.00 39.00 9 Y13-6 70L 15.10 20.20 23.50 37.00 45.00 9 252-2 70L 15.00 19.10 21.50 31.00 41.00 Totals Pen 9 93.40 122.00 144.50 204.00 256.00 "iiiiiiiiiiliiiiiiiii