THE EFFECT OF DIETARY PROTEIN SOURCE ON IRON UTILIZATION BY THE BABY PIG Thesis far the Degree of M. S. MICHIQAN STATE UNIVERSITY— STUART AUSTIN LUMB 1970 THESIS Midligan S m UniVCISit’ .3- amomo av 3'“ IIIIAE a SBIIS' 000K RWDFRV mc. uam- a. was, ABSTRACT THE EFFECT OF DIETARY PROTEIN SOURCE ON IRON UTILIZATION BY THE BABY PIG by STuarT AusTin Lumb Two Trials, involving a ToTal of 48 baby pigs, were conducTed To invesTigaTe The effecTs of isolaTed soy or high proTein casein on iron uTiIizaTion by The baby pig. Baby pigs were Taken from The sow aT 2 To 7 days of age and weaned To a dry purified dieT. Blood samples were Taken iniTialIy and aT The end of each Trial for hemaTologicaI and serological analysis. Pigs were housed in sTainless sTeel rearing cages and were fed 39 IibiTum. Pigs were alloTTed To one of six dieTary TreaTmenTs. Iron supplied as FeSO4.2H20 was added aT O, 50 and ICC ppm To provide Three levels of iron. SupplemenTal iron was added To The casein dieTs To equaTe The iron conTenT wiTh Those of The soy dieTs. Mineral balance sTudies were conducTed during The final Two weeks of each Trial. As judged by growTh and balance daTa, hemaTocriT, hemoglobin, eryThrocyTe and serum iron levels, The iron in The isolaTed soy dieTs was more available Than ThaT in The high proTein casein dieTs. Consequenle, under The condiTions of The experimenT, The iron requiremenT of The baby pig fed isolaTed soy proTein is less Than ThaT of pigs receiving casein as The proTein source. THE EFFECT OF DIETARY PROTEIN SOURCE ON IRON UTILIZATION BY THE BABY PIG By STuarT AusTin Lumb A THESIS SubmiTTed To Michigan STaTe UniversiTy in parTial fulfillmenT of The requiremenTs for The degree of MASTER OF SCIENCE DeparTmenT of Animal Husbandry I970 DEDICATION To The furTherance of Anglo-American undersTanding and To The beTTermenT of inTernaTional reIaTions beTween all naTions of The world ACKNOWLEDGEMENTS The auThor wishes To express his sincere appreciaTion To Dr. E. R. Miller and Dr. D. E. Ullrey for Their guidance and assisTance ThroughouT his graduaTe program and for Their criTical reading of The manuscripT. Thanks are also due To Dr. J. L. Gill for serving on The auThor's guidance commiTTee and To Dr. W. T. Magee for his help wiTh The sTaTisTical analysis of The daTa. Sincere graTiTude is expressed To Dr. R. H. Nelson and The Animal Husbandry DeparTmenT for The use of TaciliTies and animals and for financial supporT in The form of a graduaTe assisTanship. FurThermore, The auThor Thanks The deparTmenT for enabling him To be engaged in graduaTe sTudy aT Michigan STaTe UniversiTy and Thereby gaTher an insighT inTo The American universiTy sysTem. The auThor is also graTeful To The fellow graduaTe sTudenTs, laboraTory personnel and deparTmenT secreTaries who accepTed an expaTriaTe Englishman inTo Their midsT and gave him Their assisTance and encouragemenT many Times over. Thanks are also due To Miss PaTricia WighTman for her skillful Typlng of This Thesis. STuarT AusTin Lumb CandidaTe for The degree of MasTer of Science DISSERTATION: The EffecT of DieTary ProTein Source on Iron UTilizaTion by The Baby Pig OUTLINE OF STUDIES: Main Area: Animal Husbandry Minor Area: STaTisTics BIOGRAPHICAL ITEMS: Born: AugusT 28, I943, Halifax, Yorkshire, England UndergraduaTe STudies: UniversiTy of Leeds, England, l96l~l966 GraduaTe STudies: Michigan STaTe UniversiTy, l967-I970 Experience: Research AssisTanT, NaTionaI Animal Husbandry Research lnsTiTuTe, Kébenhavn, Denmark, l966-l967 GraduaTe AssisTanT, Michigan STaTe UniversiTy, l967-I97O LIST OF FIGURES . LIST OF TABLES LIST OF APPENDlX TABLES IV. INTRODUCTION TABLE OF CONTENTS REVIEW OF LITERATURE . DieTary FacTors AffecTing lron Minerals ViTamins OTher facTors . ProTein and Iron AbsorpTion . DieTary proTein level and iron absorpTion EffecT of proTein source on mineral absorpTion EffecT of proTein source on iron absorpTion AbsorpTion PepTides and iron absorpTion . Amino acids and iron absorpTion . EXPERIMENTAL PROCEDURE lnTroducTion . General ConducT of ExperimenTs HemaTological ParameTers . AnalyTical Procedures Serum DeTerminaTions STaTisTical Analysis RESULTS AND DISCUSSION Trial l Trial 2 O Page vii viii l5 I9 23 23 24 27 30 3| 33 33 33 37 38 39 4O 4O 48 TABLE OF CONTENTS (conT.) Page V. CONCLUSIONS . . . . . . . . . . . . . . . 59 VI. SUMMARY . . . . . . . . . . . . . . . . 60 VII. BIBLIOGRAPHY . . . . . . . . . . . . . . 62 VIIUQ APPEND'X O O O O O O O O O O O O O O O O 7' vi LIST OF FIGURES Page EffecT of dieTary proTein source and iron level on iron balance, Trial I. . . . . . . . . . 47 EffecT of dieTary proTein source and iron level on iron balance, Trial 2. . . . . . . . . . 56 vii Table I2. I3. LIST OF TABLES EffecT of proTein source on body weighT and hemoglobin levels in chicks (l4-day eXperimenTal period) . . . . . ComposiTion of experimenTal dieTs . DieTary iron levels (ppm). 0 Summarized pig performance daTa, Trial HemaTological daTa, Trial Serum iron, ToTal and unbound iron-binding capaciTy and Transferrin saTuraTion, Trial Serum proTein analyses, Trial Balance daTa, Trial I . Summarized pig performance daTa, Trial 2 HemaTological daTa, Trial 2 . Serum iron, ToTal and unbound Iron-binding capaciTy and Transferrin saTuraTion, Trial Serum proTein analyses, Trial 2 Balance daTa, Trial 2 . viii Page 29 35 4i 42 44 45 46 49 SI 53 55 LIST OF APPENDIX TABLES Mineral mixTures used in experimenTal dieTs . ViTamin mixTure used in experimenTal dieTs . . Pig performance daTa, Trial l . . . . . . HemaToIogical daTa, Trial l . . . . . . . Serum iron, ToTal and unbound iron-binding capaciTy and Transferrin saTuraTion daTa, Trial Serum proTein analyses, Trial l . . . . . Balance daTa, Trial 2 . . . . . . . . . Pig performance daTa, Trial 2 . . . . . . HemaTological daTa, Trial 2 . . . . . . . Serum iron, ToTal and unbound iron-binding capaciTy and Transferrin saTuraTion daTa, Trial Serum proTein analyses, Trial 2 . . . . . Balance daTa, Trial 2 . . . . . . . . . Page 7I 72 73 74 75 76 77 78 79 80 BI 82 I. INTRODUCTION In The swine indusTry Today There is a Trend Toward early weaning of pigs so ThaT The sow may be rebred soon afTer farrowing To maximize her reproducTive poTenTiaI. Several commercial swine producers, boTh in The UniTed STaTes and Europe, are rearing pigs which have been weaned aT one week of age or less. For This pracTice To be successful, an economical early weaning dieT musT be developed. MosT dry early weaning dieTs include milk producTs as The proTein source. Because milk producTs are cosle, iT would be desirable To use less expensive soybean proTein. Many of The nuTrienT requiremenTs of The early weaned baby pig, especially The mineral requiremenTs, have been deTermined using purified dieTs conTaining casein as The proTein source. Several workers have reporTed ThaT The availabiliTy of zinc is less in dieTs conTaining soybean meal Than in dieTs conTaining milk proTein (Morrison and SareTT, l958; O'Dell and Savage, I960; Oberleas g: 21" l962; Edwards, I965). In addiTion, Miller gl._1, (I965) sTaTed ThaT baby pigs fed soy dieTs reTained less calcium, phosphorus and mag- nesium Than pigs fed casein dieTs. In view of These reporTs, a sTudy was underTaken To deTermine The effecT of dieTary proTein source on The availabiliTy and uTiliza- Tion of iron by The baby pig. This quesTion also has addiTional significance in ThaT if The iron requiremenT of The baby pig can be meT from dieTary sources, The necessiTy of using an injecTable form of iron, plus The inherenT cosTs involved, could be eliminaTed. II. REVIEW OF LITERATURE DieTary FacTors AffecTing_|ron AbsorpTion Minerals DieTary iron level The effecT of The dieTary iron level on absorpTion is direcTIy reIaTed To The iron sTaTus of The individual under consideraTion. Thus, anemic individuals will absorb a considerably higher percenTage of iron Than a normal individual. This has been shown To be The case wiTh humans (Pirzio-Biroli §I_ I., I958); dogs (STewarT, I953); chickens (FeaThersTon g1,gl,, I968) and raTs (Pollack §1_§l,, I964; Greenberger and RupperT, l966; Pearson g1_gl,, I967). Ullrey §1_gl, (I960) sTaTed ThaT The oral iron requiremenT for The baby pig was I25 ppm. Pigs fed dieTs conTaining 25, 35 and l25 ppm of iron absorbed 92.2, 7I.4 and 49.9% of The iron, respecTively, indicaTing decreased absorpTion wiTh an increasing level of dieTary iron. MaTrone ._1._L. (I960) also esTimaTed The iron requiremenT of The baby pig. These workers esTimaTed The uTilizaTion of dieTary iron for hemoglobin synThesis and found ThaT The uTilizaTion values for pigs receiving 40 and 80 ppm of dieTary iron were significanTIy lower (P<0.05) Than Those for pigs receiving IO or 20 ppm. Valence form of iron WiTh reference To This Topic, species differences do exisT and Therefore generalizaTions can only be made wiTh regard To wiThin-species comparisons. 3 LoTTrup (I934) compared The effecT of oral ferrous and ferric salTs on hemoglobin levels in anemic children. He found ThaT The ferrous forms were much more effecTive in increasing hemoglobin values. McCance ‘QI‘_L. (I943) and Moore §1__l, (l943) also found ThaT ferrous forms were more readily absorbed Than The ferric, as judged by serum iron levels. Moore §1_QL. (I944) used radioacTive ferrous and ferric salTs and esTimaTed absorpTion by The amounT of iron appearing in The hemoglobin. They found ThaT The bivalenT form was absorbed IE To l5 Times more readily Than The ferric form. RecenT research from Holland would appear To casT doubT on The validiTy of The assumpTion ThaT differences in The uTilizaTion of iron are a direcT reflecTion of differences in absorpTion. WiITink g1H_L. (l966) measured The absorpTion and uTilizaTion of orally ingesTed ferric and ferrous salTs. AbsorpTion was calculaTed by The use of balance Trials. UTilizaTion of 59Fe was calculaTed from blood volume and eryThrocyTe radioacTiviTy. The auThors, using boTh ferrous and ferric salTs, found a significanT negaTive correIaTion beTween inTesTinal absorpTion and uTilizaTion. IT was furTher shown ThaT paTienTs given ferrous chloride or ferric versenaTe absorbed 20 or 22% of The dose respecTively, alThough uTilizaTion of The ferrous chloride (32%) was considerably greaTer Than ThaT of The ferric versenaTe (9%). From This iT would appear ThaT absorpTion of The Two forms is approximaTely equal. The auThors also sTaTed ThaT The ferrous form was uTilized To a greaTer exTenT Than The ferric form, alThough in general if has been assumed ThaT uTilizaTion of The Two forms is The same. In dogs, Moore e1.§l, (I944) observed ThaT The uTilizaTion of radioacTive ferrous and ferric iron for hemoglobin synThesis was abouT equal alThough some dogs absorbed more of The ferrous form. The auThors suggesTed ThaT dogs may reduce The ferric form more efficienle Than 4 humans. However, Hahn g1_al. (I945) using Three anemic dogs found ThaT There was greaTer upTake of The ferrous Than The ferric form. WiTh raTs, several workers have shown ThaT boTh ferrous or ferric forms are equally available for hemoglobin regeneraTion in anemic animals (AusTioni and Greenberg, I940; STreeT, I943; Blumberg and Arnold, l947). RecenT work by FriTz (I969) indicaTed ThaT several forms of ferrous iron were considerably more available for hemoglobin repleTion in anemic raTs and chickens Than ferric forms. Because of The efficacy of injecTable iron compounds as hemaTinics for pigs, research involving comparisons of oral forms of iron has been raTher limiTed. PickeTT _1_g1, (I96I) sTudied The availabiliTy of iron in differenT compounds using baby pigs reared on a dried skim milk semi-purified raTion. In The Three Trials carried ouT, pigs receiving ferrous sulfafe had significanle higher hemoglobin levels (P<0.0|) Than pigs receiving eiTher ferrous carbonaTe or ferric oxide. Pigs receiving ferrous carbonaTe had higher hemoglobin levels Than pigs receiving ferric oxide, alThough This difference was noT significanT. Harmon gl_gl, (I967), also working wiTh baby pigs, invesTigaTed The efficacy of ferric ammonium ciTraTe as an oral hemaTinic. Using a semi-purified dIeT The auThors concluded ThaT, as judged by hemoglobin values and weighT gains, ferric ammonium ciTraTe was as efficienT an oral hemaTinic as ferrous sulfaTe. From The liTeraTure reviewed, ferrous iron, in general, is beTTer absorbed Than The ferric form. However, This may in facT be jusT a consequence of The greaTer solubiIiTy of The ferrous form. In order To resolve This maTTer, iT would be necessary To compare The absorpTion of ferrous and ferric salTs which had idenTical solubiliTies aT a pH of around 6.5 To 7.0. Iron salTs Nakamura and MiTchell (I943) measured The raTe of hemoglobin regeneraTion in anemic raTs fed various forms of iron salTs. They reporTed ThaT The iron in ferric chloride was Twice as effecTive as ThaT in ferric phyTaTe for hemoglobin regeneraTion. In a similar experimenT, Fuhr and STeenbock (I943) sTaTed ThaT The availabiliTy of iron from ferric phyTaTe was I95 less Than ThaT of ferric ammonium sulfaTe for hemoglobin regeneraTion. Also working wiTh raTs, Freeman and Burrill (l945) compared The reTenTion of iron from several differenT sources. The compounds showed The following order of effecTiveness in relaTion To hemoglobin regeneraTion: ferric chloride>sodium ferric orThophosphaTe=ferric phosphaTe>reduced iron sodium iron pyrophosphafe.~ Blumberg and Arnold (l947) also found ThaT ferric chloride was superior To ferric orThophosphaTe in Terms of hemoglobin regeneraTion. Working wiTh pigs, Harmon g1_gi, (I968) noTed ThaT ferrous carbonaTe was considerably less soluble Than ferrous sulfaTe. They showed ThaT a ferrous sulfaTe-supplemenTed dieT (64 ppm of iron) gave significanTIy higher hemoglobin levels Than a dieT conTaining ferrous carbonaTe (70 ppm of iron). More recenTIy, Harmon gl.gl, (I969) sTaTed ThaT a survey of Trace mineral salTs currenle used in swine dieTs indicaTed ThaT ferrous carbonaTe was mosT commonly used To provide supplemenTal iron. In view of This, several experimenTs were conducTed To furTher deTermine The efficacy of ferrous carbonaTe and ferrous sulfaTe. Pigs were fed a purified dieT conTaining casein as The proTein source. Hemoglobin values of pigs receiving ferrous sulfaTe were significanfly greaTer (P<0.0l) Than Those of pigs receiving an equal level of iron 6 (80 ppm) supplied as ferrous carbonaTe. FurThermore, The hemoglobin levels of pigs receiving The ferrous carbonaTe were equal To Those of The conTroI pigs receiving 29 ppm of iron. These daTa indicaTe ThaT ferrous carbonaTe did noT supporT normal hemoglobin levels, confirming The group's previous observaTions (Harmon e1_§1,, I968). IT was also shown ThaT ferrous carbonaTe added To dieTs in varying amounTs To give levels of IS To I47 ppm of iron was ineffecTive in increasing hemoglobin levels. In addiTion, FriTz (I969) recenle reporTed a relaTive biological value of zero for ferrous carbonaTe fed To chickens. Research from The UniversiTy of Florida also indicaTed ThaT ferrous sulfaTe was superior To ferrous carbonaTe as a source of iron for The young pig. A dieT conTaining 90 ppm of iron supplied as ferrous sulfaTe gave significanle higher hemoglobin levels (P<0.0l) Than dieTs conTaining IO3 or l05 ppm of iron supplied as ferrous carbonaTe (Ammerman .;L._L.. I969). The same group also compared samples of ferrous carbon- aTe which differed in Their solubiliTy in acid as iron sources for young pigs. When fed wiTh a basal dieT, low, medium and high solubiliTy ferrous carbonaTe dieTs gave hemoglobin levels of 7.3, 7.5 and 8.7 g/lOO ml of blood. This would be expecTed as mosT of iron absorpTion occurs in The upper duodenum where The pH is sTill quiTe acid. Thus, The differing availabiliTy of iron for absorpTion from The various salTs is in parT a consequence of Their differing solubiliTies in acid media. QBLEMI Anderson _I_gl, (I940) sTudied The effecT of calcium on hemoglobin regeneraTion in anemic raTs. The auThors noTed ThaT increasing The dieTary calcium level resulTed in reduced iron absorpTion. KleTzien (I940) also found ThaT increased levels of calcium resulTed in decreased iron absorpTion. The addiTion of IS of calcium To a basal dieT fed To anemic raTs reduced The iron conTenT of all Tissues excepT The spleen. The average liver, blood and carcass values were 57, 86 and 90% of The respecTive conTrol values. Increasing The level of calcium supplemenTaTion To 3% of The dieT resulTed in average liver, blood and carcass values which were 28, 72 and 6IZ of The respecTive conTrol values. Richards and Greig (I952) reporTed finding pale livers and enlarged flabby hearTs in weanling mice whose moThers' dieTs conTained I To 2% of added calcium carbonaTe. The dams fed a high level of calcium carbonaTe in The dieT were also anemic. ConTinuing his research wiTh mice, Greig (l954)carried ouT experimenTs To find if The anemia was due To calcium carbonaTe E§j§g_or To some oTher deficiency, induced by calcium carbonaTe. SubsTances which were considered likely To affecT hemoglobin synThesis (e.g.. copper and pyridoxine) were fed in excessive amounTs along wiTh calcium carbonaTe. However, all addiTives failed To prevenT anemia developing. Consequenle, Greig concluded ThaT calcium carbonaTe exerTed iTs anemigenic acTion Through some inTerference wiTh The assimilaTion or uTilizaTion of iron. The effecT of bone meal on The uTilizaTion of iron by anemic raTs was invesTigaTed by Chapman and Campbell (l957a). Bread dieTs, SUpplemenTed wiTh Three levels of bone meal providing 3I70, 4040 and 7330 PP!!! of calcium and six levels of ferrous sulfaTe (2I.6 To l48.2 ppm of (TTCN1) were fed gg,libiTum To anemic raTs over a IO-week period. WiTh each, level of iron fed, hemoglobin levels Tended To be highesT on The ’OWeST level of bone meal and vice-versa. FurThermore, aT all Three 8 levels of bone meal fed, hemoglobin levels Tended To increase wiTh increasing levels of iron. Thus if would appear ThaT increasing The amounT of bone meal in The dieT reduced The amounT of iron available for absorpTion or uTilizaTion. In furTher work, Chapman and Campbell (l957b) carried ouT a sTudy To deTermine wheTher The calcium or The phosphaTe porTion of The bone meal was responsible for The inTerference wiTh iron uTilizaTion. IT was shown ThaT There was no significanT difference in hemoglobin regeneraTion of anemic raTs fed a conTrol dieT (80% bread) conTaining I670 ppm of phosphorus or of anemic raTs fed The same dieT supplemenTed eiTher wiTh disodium phosphaTe or sodium hexaphosphaTe, The phosphorus conTenT of These Two dieTs being 3620 and 36I0 ppm respecTively. However, The hemoglobin regeneraTion of anemic raTs fed The conTrol dieT supplemenTed wiTh eiTher calcium carbonaTe (7900 ppm ToTaI calcium), or calcium chloride (7290 ppm ToTal calcium) , was considerably less Than ThaT of anemic raTs fed The conTrol dieT conTaining 3200 ppm calcium. Thus, under The condiTions of The sTudy, if was found ThaT phosphaTe did noT inTerfere wiTh iron absorpTion, whereas calcium did. Working In India, De and Basu (I949) found ThaT human subjecTs kepT on a dieT of sago sugar and buTTerfaT for l2 days almosT mainTained iron balance. However, when 500 To IOOO mg of calcium IacTaTe was ingesTed wiTh The dieT, The subjecTs were in negaTive iron balance, mainly Through an increase in fecal Iron. IT was concluded ThaT The excess calcium was probably precipiTaTed as insoluble calcium phosphaTe which removed a large amounT of iron along wiTh iT. In furTher experimenTs wiTh human subjecTs, ApTe and VenkaTchalam (I964) compared The effecTs of Three differenf levels of supplemenTary calcium, ranging from 360 To I600 mg/day. The raTio of phyTin phosphorus To ToTal phosphorus was kepT consTanT aT 40%. WiTh a daily inTake of 400 mg of calcium, subjecTs on an iron inTake of l6.6 mg were in negaTive iron balance. SubjecTs ingesTing IOOO mg of calcium and l6.6 mg of iron/day absorbed 4% of The iron, while increasing The calcium level To I500 mg/day resulTed in l6% of The dieTary iron being absorbed. IT can be seen ThaT increased calcium levels in This InsTance resulTed in increased iron absorpTion. IT is possible ThaT aT The higher levels of calcium supplemenTaTion, sufficienT calcium was available To precipiTaTe The phyTaTe presenT in The dieT. Consequenle The iron, which mighT have been precipiTaTed as iron phyTaTe, was Then available for absorpTion. Very liTTle research has been carried ouT relaTed To The effecTs of calcium on iron absorpTion wiTh swine. Working in ScoTland, Greig (l960) fed young pigs a basal wheaT and milk dieT. Pigs receiving This dieT had significanfly higher hemoglobin levels af 8 weeks of age (P<0.0I) Than pigs receiving The same dieT supplemenTed wiTh 2% of calcium carbonaTe. Greig concluded ThaT calcium carbonaTe reduced The availabiliTy of iron in The small inTesTine due To iTs anTacid properTies. However, There is a possibiliTy ThaT The reducTion in absorpTion was due To The carbonaTe ion and noT To The calcium. PickeTT gI_ l. (l96l) showed ThaT The availabiliTy of iron carbonaTe was much less Than ThaT of ferrous sulfaTe and iTs is possible ThaT The reducTion observed by Greig was due To iron carbonaTe formed in The inTesTinal TracT. 0-“: Cu ~ I QXCI up, a 3.5. IO In general, iT can be sTaTed ThaT dieTary calcium supplemenTaTion, regardless of species, reduces iron absorpTion, alThough a definiTe explanaTion for This occurrence appears To be lacking. Phosphorus Kinney §I_§1,(l949) sTudied The influence of dieT on iron absorpTion in The raT. The Two basal dieTs, Purina dog chow and a corn griT meal, conTaining 350 and 27 ppm of iron respecTively, were supplemenTed wiTh an addiTional 3IOO ppm of iron supplied as ferric ciTraTe, giving four TreaTmenTs in all. Liver iron deTerminaTions were made aT The TerminaTion of The experimenT, and iT was found ThaT The liver iron conTenT of raTs receiving The supplemenTed corn griT dieT was considerably greaTer Than ThaT of raTs receiving The corn dieT alone (l9.4 and 69.6 mg of iron/IOO g of liver respecTively). ‘ However, The liver iron conTenT of raTs fed The supplemenTed Purina dieT was only sligthy greaTer Than ThaT of raTs receiving The unsupplemenfed Purina dieT (9.0 and I3.9 mg of iron/IOO g of liver). The auThors noTed ThaT The liver iron conTenT of The corn griT-fed raTs exceeded The ToTal body iron conTenT of normal raTs, and considered ThaT The low phosphorus conTenT (400 ppm) of The corn griT dieT was responsible for This excessive deposifion of iron. In furTher experimenTs, HegsTed, Finch and Kinney (I949) again working wiTh raTs fed a corn griT dieT supplemenTed wiTh 0.3l% of iron, found ThaT The amounT of liver iron was inversely relaTed To The phosphorus conTenT of The dieT. BuTTner and Muhler (I959) worked wiTh Sprague Dawley raTs which were fed a sTock corn dieT conTaining 0.32% of calcium and O.3l% of phosphorus. They found ThaT a six-fold increase in liver iron concenTraTion occurred in raTs receiving 50 mg of iron/day compared wiTh The conTroI group, which received no supplemenfal iron. However, The liver iron conTenT of raTs receiving a daily supplemenT of 50 mg of iron and 50 mg of phosphorus was significanle less (P<0.000I) Than ThaT of raTs receiving supplemenTal iron alone (50 mg/day). FurThermore, The liver iron conTenT of raTs receiving 50 mg of iron and I00 mg of phosphorus/day was less Than ThaT of The group receiving 50 mg of iron and phosphorus/day. O'Donovan 41 _L. (I963) working wiTh baby pigs, sTudied The effecTs of Three differenT dieTary phosphorus levels fed in conjuncTIon wiTh dieTary Iron levels of 80, 2500 and 5000 ppm. Levels of l.2 or 0.6% phosphorus reduced The Toxic effecTs of high iron levels as compared wiTh 0.3% phosphorus supplemenTaTion. Consequenfly iT would appear ThaT in pigs receiving excessive amounTs of iron and higher levels of phosphorus, much of The phosphorus was forming insoluble complexes wiTh The iron, Thereby rendering The iron unavailable for absorpTion and hence reducing The Toxic effecT. Cogper IT is well known ThaT copper is essenTiaI for hemoglobin synThesis. Even wiTh adequaTe supplies of dieTary iron, if copper is lacking, anemia will develop (CarTwrighT 21.g1,, I956). This indicaTes The involvemenT of copper in adequaTe iron uTilizaTion. Many workers have shown ThaT copper deficiency anemia in swine can be successfully TreaTed wiTh copper supplemenTaTion, providing adequafe iron is also supplied (HarT gi,gl,, I930; Schusze 21_ I., I936; Lahey g1.gl,, I952; WinTrobe 119;” I952). I2 Gubler ;1 _L. (I952) found ThaT baby pigs fed a basal dieT supplemenTed wiTh 4.3 mg of iron and 0.5 mg of copper per kg of body weighT per day absorbed 6.l% of an orally adminisTered dose of 59Fe, whereas pigs receiving The same level of iron, buT no supplemenTal copper, absorbed only l.85% of The labelled iron. As judged by plasma iron levels, iT was also shown ThaT liTTIe iron was absorbed in The absence of dieTary copper, whereas in The presence of dieTary copper, large amounTs of iron were absorbed. Working in England, Cassidy and Eva (I958) fed bacon pigs dieTs conTaining l25, 250 or 500 ppm of copper. The liver iron values Tended To decrease wiTh increasing levels of copper in The dieT, even Though all pigs received The same level of dieTary iron (400 ppm). Working wiTh baby pigs, Ullrey 91_gl, (l960b) compared dieTs conTaining 6, l6 and l06 ppm of copper. They found ThaT 6 ppm of copper gave normal growTh and eryThropoiesis. Serum iron concenTraTion was increased aT The I6 ppm level, and liver iron conTenT was shown To increase wiTh increasing levels of dieTary copper. In furTher work carried ouT aT Michigan STaTe, RiTchie 21_gl, (I963) compared The effecTs of adding various levels and combinaTions of copper and zinc To a high calcium dieT fed To growing pigs. The addiTion of 250 ppm of copper To The basal raTion conTaining l3.l ppm of copper and 42.2 ppm of zinc resulTed in hemoglobin and hemaTocriT values which were significanfly lower (P<0.05) Than Those from pigs on The basal raTion. Workers aT The RoweTT Research lnsTiTuTe fed even higher levels of copper To pigs. SupplemenTaTion of a basal dieT wiTh 75 ppm of copper resulTed in anemia developing, alThough pigs receiving The same level of copper wiTh an addiTional 750 ppm of iron did noT become anemic (SuTTle and Mills, I964). he i '63 73'. UPI cm II‘ :3? Di I3 Working wiTh male albino raTs, Chase T I. (I952) sTudied The effecT of various levels of dieTary copper (0.05 To l.0 mg/day) on 59F9 absorpTion and found ThaT maximum iron absorpTion occurred wiTh raTs fed 0.25 To 0.5 mg of copper per day. IT was also reporTed ThaT The influence of copper on iron absorpTion was noT due To The simul- Taneous adminisTraTion of copper wiTh iron, buT appeared To be cor- relaTed wiTh The copper level of The Tissues. However, Kinnamon (I966) showed ThaT There was no significanT difference in liver iron conTenT beTween raTs fed a conTroI dieT conTaining no supplemenTal copper for 5 weeks and raTs receiving The same dieT supplemenTed wiTh 0.02% copper over The same period of Time. 2139_ Magee and MaTrone (I960) using raTs, sTudied The effecT of zinc on The absorpTion of 59Fe. ResulTs indicaTed ThaT There was liTTle difference in absorpTion beTween The conTrol and zinc-fed raTs, alThough The zinc conTenT of The dieTs was noT sTaTed. Kinnamon. (l966) also reporTed ThaT There was no significanT difference in The absorpTion of 59Fe beTween raTs receiving a dieT conTaining 0.75% of zinc and raTs receiving a dieT conTaining no zinc supplemenTaTion. Also There was no significanT difference in The amounT of radioiron reTained in The liver by The same Two groups. Also working wiTh raTs, Bunn and MaTrone (l966) found ThaT dieTary zinc levels of 200 and 400 ppm increased liver iron levels as compared To a basal level of 9 ppm of zinc. This finding is in conTrasT To The oTher reporTs quoTed. Regarding work wiTh swine, Cox and Hale (I962) invesTigaTed The effecT of 0.2 and 0.4% dieTary zinc on liver iron in weanling pigs. The liver iron conTenT of pigs receiving 0.4% of zinc was significanle I4 less (P<0.0l) Than ThaT of The conTroI group which received 40 ppm of added zinc. There was no significanT difference in liver iron levels beTween The conTrols and pigs fed 0.2% zinc. The auThors noTed ThaT even aT The 0.4% zinc level, no ToxiciTy problems were encounTered, alThough growTh raTe was slighTIy reduced, as compared To The oTher Two TreaTmenTs. Manganese HarTman §1_gl. (I955) sTressed ThaT as liTTle as 45 ppm of supplemenTal manganese fed To anemic lambs resulTed in decreased hemoglobin concenTraTions and serum iron levels. Higher levels of manganese, up To 5000 ppm, resulTed in decreased iron levels in The spleen, liver and kidney. In a furTher Trial, anemic lambs were fed a roughage dieT supplemenTed wiTh 0, IOOO or 2000 ppm of manganese. Hemoglobin regeneraTion was reTarded and serum iron depressed in lambs fed dieTs conTaining eiTher IOOO or 2000 ppm of manganese. FurTher experimenTs To deTermine The effecTs of high levels of manganese on hemoglobin regeneraTion were carried ouT by MaTrone _1H_L. (I959). using rabbiTs and baby pigs. SupplemenTal manganese (2000 pm) depressed hemoglobin formaTion in boTh rabbiTs and baby pigs. However, a dieTary supplemenT of 400 ppm of iron overcame This depressing effecT. The minimum level of manganese in The dieT ThaT inTerfered wiTh hemoglobin formaTion was 50 To l25 ppm. l5 ViTamins Pyridoxine Working wiTh 30 lb pigs, Hughes and Squibb (I943) found ThaT a dieT deficienT in pyridoxine resulTed in poor appeTiTe, reduced growTh and The developmenT of microcyTic hypochromic anemia. On The addiTion of pyridoxine To The dieT, however, The blood picTure reTurned To normal. Miller §1_§1, (I957) deTermined The pyridoxine requiremenT of The baby pig, using a synTheTic milk dieT. The hemoglobin levels of conTrol pigs were significanle less (P<0.0l) during The Third, fourTh and fifTh weeks Than Those of pigs receiving pyridoxine. Pyridoxine is necessary for proToporphyrin synThesis and proToporphyrin is required for hemoglobin synThesis (CarTwrighT and WinTrobe. I948). Consequenle, 'The low hemoglobin levels observed by Hughes and Squibb and Miller g1_gl, were due To a lack of proToporphyrin raTher Than To a lack of iron. In conTrasT, Gubler §1_§1, (I949) found ThaT iron absorpTion of pyridoxine-deficienT raTs was greaTer Than ThaT of The conTroI raTs fed The same level of iron (I mg/day). More recenle, Neal and Pearson (I962) also working wiTh raTs, sTudied The relaTionship beTween pyridoxine deficiency and iron absorpTion aT various levels of iron inTake. In Their firsT experimenT, an iron-free dieT was fed To conTrol and pyridoxine-deficienT groups for 5 weeks. All raTs were given O.l mg of 55‘59Fe by sTomach Tube and killed 24 hours lafer. IT was found ThaT pyridoxine-deficienT raTs absorbed significanle less iron Than The conTrol group (P 0.05).. In The nexT experimenT, The Two groups were fed iron-free dieTs for I0 weeks afTer which They were fed O.l mg of 55.59Fe/day for I4 days. In This case, There were no significanT l6 differences in iron absorpTion. However, when 55"59Fe was fed aT a level of I mg/day over an IB-day period following l2 weeks on The iron-free dieTs, The pyridoxine-deficienT group absorbed significanfly more iron Than The conTrol group (P<0.05). The resulTs of This lasT experimenT are in agreemenT wiTh Those of Gubler 21.2L, (I949). . In conTrasT, Shen §1_gl, (I964) found ThaT pyridoxine deficiency reduced iron uTilizaTion. RaTs fed a pyridoxine-deficienT dieT conTaining 22.2 mg iron/IOO 9 developed a severe microcyTic hypochromic anemia afTer 40 To 50 weeks on Trial. This anemia responded promple To pyridoxine adminisTraTion, hemoglobin levels recovering To normal afTer 2 weeks of pyridoxine Therapy. ViTamin Biz Neuman gl.gl, (I950) deTermined The viTamin 8.2 requiremenT of The baby pig fed a synTheTic milk dieT. Increasing levels of supplemenTal BIZ gave increasing hemoglobin values, The highesT value (I4.3 g/IOO ml blood) resulTing from pigs receiving 5| mcg of B'z/kg dry maTTer. According To Wohl and GoodharT (I968) viTamin BIZ is involved indirechy in deoxyribose nucleic acid formaTion. Consequenle, if BIZ is lacking The miToTic acTiviTy of The bone marrow is decreased, resulTing in decreased eryThropoiesis. In view of This, The increased hemoglobin values observed by Neuman gl_gl. (I950) were probably a consequence of The effecT of BIZ on eryThropoiesis. VlTamin C Moore (I955) showed ThaT human subjecTs absorbed a greaTer percenTage of 59Fe when fed on a dieT of eggs and ciTrus fruiT juices Than when fed eggs alone. The auThor suggesTed ThaT ascorbic acid ‘ I7 presenT in The fruiT juice increased absorpTion by promoTing The reducTion of ferric iron To The ferrous form. When ascorbic acid was subsTiTuTed for The ciTrus juice, similar resulTs were obTained. OTher workers have also shown ThaT foods conTaining appreciable amounTs of ascorbic acid, such as TomaToes and orange juices, were effecTive in reducing ferric iron To The ferrous sTaTe (Kirch _e_‘l_'_ a_l,, I947; Berghelm and Kirch, I949). The effecT of ascorbic acid on iron absorpTion in raTs was I. (I947). They also found ThaT ascorbic invesTigaTed by Groen e1 __ acid increased iron absorpTion. IT was concluded ThaT The ascorbic acid effecTiver reduced inTesTinal pH and enabled more ferrous iron To be absorbed. Greenberg g: g_l_. (I957) furTher showed ThaT The raTe of hemoglobin regeneraTion was consisTenle greaTer in raTs given supplemenTs of iron and ascorbic acid Than in raTs supplied wiTh iron AfTer observing ThaT ascorbic acid resulTed in increased iron alone. absorpTion from ligaTed raT inTesTinal loops, Hopping and Ruliffson ( l966) suggesTed ThaT ascorbaTe-iron chelaTes may be formed and be responsible for The increased iron absorpTion. This was shown To be The case by Helbock and Salen (I967). They showed ThaT The upTake Of 59Fe by ligaTed raT inTesTinal segmenTs was increased when an a‘~5<=C>r-baTe-iron chelaTe was used. They sTaTed ThaT low molecular We".QhT chelaTes are necessary To mainfain iron in a soluble and permeab Ie form. Greenberg and RhineharT (I955) observed hypoferremia and anemia ' n ‘l‘wo rhesus monkeys exhibiTing chronic viTamin C deficiency. Oral i "on alone (50 mg/day for 4| days) had very liTTle effecT on This c: 0nd iTion, buT when supplemenTed wiTh ascorbic acid The hypoferremia III M l3: and anemia were markedly reduced. ViTamin E lndovina (I95l) found ThaT rabbiTs exhibiTing sympToms of viTamin E deficiency had low hemoglobin levels. The adminisTraTion of 30 mg of viTamin E/day for IS days resulTed in increased hemoglobin values. ScoTT g1_ l. (I955) developed a dieT for use in The sTudy of viTamin E deficiency in The chick. Birds receiving This basal dieT displayed a microcyTic anemia and a low reTiculocyTe counT, and The auThors indicaTed ThaT viTamin E mighT be concerned in eryThropoiesis. Working wiTh primaTes, Day and Dinning (I956) found ThaT anemia developed in rhesus monkeys fed a viTamin E-deficienT dieT. InjecTion of 20 mg of cr-Tocopherol phosphaTe resulTed in The hemaTocriT value increasing from 30% To 44% over a l9-day period. Greenberg ;L._L. (I957) sTudied The effecTs of supplemenTs of iron wiTh ascorbic acid and viTamin E on hemoglobin regeneraTion in milk-fed anemic raTs. They found ThaT The raTe of hemoglobin regeneraTion was consisTenle greaTer in raTs receiving all Three supplemenfs Than wiTh iron alone or wiTh iron plus eiTher of The ViTamins. In a conTinuaTion of This research, Tucker §1_gl. (I957) subsTiTuTed diphenyl-p-phenylenediamine (DPPD) for viTamin E in order To ascerTain wheTher an anTioxidanT would sTimulaTe hemoglobin regeneraTion. As in The previous work, milk-fed anemic raTs were used. IT was found ThaT hemoglobin regeneraTion was greaTesT in The group receiving iron, ascorbic acid and The anTioxidanT as compared wiTh groups receiving eiTher iron alone or iron plus eiTher ascorbic acid or DPPD. l9 Thus, iT would appear ThaT eiTher viTamin E or a biologically acTive anTioxidanT, and ascorbic acid are inTerrelaTed and exerT a considerable effecT on iron meTabolism in anemic raTs. OTher FacTors PhyTaTe McCance §I_g1, (I943) PosTulaTed ThaT phyTaTes inTerfere wiTh iron absorpTion by precipiTaTing iron as insoluble iron phyTaTe, Thus rendering The iron unavailable for absorpTion. In balance sTudies carried ouT wiTh human subjecTs, Widdowson and McCance (I942) found ThaT more iron was absorbed from whiTe bread Than from brown, in spiTe of The facT ThaT iron inTakes were 50% higher on The brown bread dieTs. The reduced absorpTion from brown bread was aTTribuTed To iTs higher phyTaTe conTenT. FurThermore, The brown bread conTained more inorganic phosphorus, and hence some iron could have been precipiTaTed as ferric phosphaTe. McCance 21”_L. (l943) working wiTh human subjecTs noTed ThaT when large doses of ferric or ferrous ammonium sulfaTe were fed along wiTh a sTandard breakfasT of jam, and whiTe bread conTaining sodium phyTaTe, The increase in serum iron levels was less Than when The iron salTs and bread conTaining no added phyTaTe were fed. Assuming ThaT The rise in serum iron was proporTional To The amounT of iron absorbed, iT was concluded ThaT sodium phyTaTe InTerfered wiTh iron absorpTion by reacTing wiTh The iron as if passed Through The inTesTinal TracT and precipiTaTing if as insoluble ferric phyTaTe. Using seven differenT TesT meals, Sharpe 21.§1, (I950) invesTigaTed The effecT of phyTaTe on 59Fe. The absorpTion of 55Fe or Using meals composed mainly of rolled 20 oaTs and milk, The auThors sTaTed ThaT There was no correlaTion beTween The phyTaTe conTenT of The rolled oaTs and The reducTion in iron absorpTion. Meals 4 and 7 were boTh composed of milk and rolled oaTs, The phyTaTe conTenT of meal 4 being approximaTely 50% higher Than meal 7. The percenTage of radioacTive iron absorbed was 9.8l and 8.84 for The Two meals respecTively. IT was poinTed ouT, however, ThaT These meals conTained abundanT amounTs of calcium, quiTe in excess of The amounT required To precipiTaTe The phyTaTe in The dieT as calcium phyTaTe. Thus, a possible explanaTion for The lack of correlaTion beTween The phyTaTe conTenT of The rolled oaTs and The reducTion in iron absorpTion was The preferenfial combinaTion of The calcium in The milk wiTh The phyTaTe, making iT unavailable for combinaTion wiTh The iron in The meals. In The same experimenT, when sodium phyTaTe was added To a TesT meal, iron absorpTion was considerably reduced. Indian workers have also shown ThaT phyTaTe exerTs a considerable effecT on iron absorpTion. Hussain and PaTwardhan (I959) carried ouT several experimenTs wiTh healThy male subjecTs. Cereal dieTs, wiTh The proporTion of phyTaTe phosphorus To ToTal phosphorus kepT af 8% and 40%, were used. WiTh an iron inTake of around 22 mg/day, iron absorpTion was II% and 3% for The Two dieTs, respecTively. ApTe and VenkaTachalam (I962), also working In India, found ThaT an inTake of II.7 mg of iron/day was insufficienT To meeT requiremenTs when a cereal dieT, in which The proporTion of phyTin phosphorus To ToTal phosphorus was kepT aT 40%, was fed To human subjecTs. SubjecTs on an inTake of I6.4 mg of iron/day absorbed less Than l%; however, wiTh an inTake of 2l.6 mg, reTenTion was 30% and all subjecTs were in 2| posiTive iron balance. From This, The auThors concluded ThaT a saTisfacTory level of iron inTake on cereal dieTs conTaining 40% phosphorus as phyTaTe phosphorus appeared To be beTween l7 and 2l mg of iron/day. This level is nearly double ThaT recommended by The UniTed STaTes Food and NuTriTion Board (l968). From The above reporTs, iT can be seen ThaT phyTaTe considerably reduces The amounT of iron available for absorpTion. In conTrasT, Foy _1._1, (I959) using dieTs of bread, jam and sodium phyTaTe fed To human subjecTs reporTed no consisTenT effecT of dieTary phyTaTe on The absorpTion of radioacTive ferric chloride. The auThors considered ThaT phyTaTes 2§£_§g_had no adverse effecT on iron absorpTion buT ThaT The producTs of Their hydrolysis may include amounTs of phosphaTes which would combine wiTh The available iron in The inTesTine. AparT from human subjecTs, raTs have also been used To sTudy The effecT of phyTaTe on iron absorpTion. SaThe and Krishnamurfhy (I953) sTudied hemoglobin regeneraTion in anemic raTs and concluded ThaT phyTin phosphorus inhibiTed iron absorpTion. However, neiTher The phyTaTe nor The iron conTenT of The dieTs used were reporTed, and The differences in values for hemoglobin regeneraTion amongsT TreaTmenT groups were noT sTaTisTically significanT. In conTrasT, Harrison and Mellanby (I942) found ThaT The addiTion of sodium phyTaTe To The dieT of anemic raTs receiving 0.3 mg iron/day did noT appear To inhibiT hemoglobin regeneraTion when compared wiTh The conTroI group. More reneenle, Cowan T _1, (I966) compared hemoglobin regeneraTion in groups of anemic raTs fed purified dieTs conTaining l0 or 20 ppm of iron, in which eiTher 45% or 75% of The ToTal phosphorus was replaced winI phyTaTe phosphorus. Hemoglobin regeneraTion was more rapid in Ely” fni 2M iv: 35 22 The groups receiving 20 ppm of iron Than in The groups receiving I0 ppm. However, The hemoglobin values showed ThaT, even aT The l0 ppm level, The raTe of hemoglobin regeneraTion was noT affecTed by The presence of eiTher level of dieTary phyTaTe. In view of This, if was concluded ThaT high levels of phyTaTe have no effecT on iron absorpTion in The raT. CarbohydraTes ’Herndon g1_gL. (I958) showed ThaT D-sorbiTol increased The absorpTion of 59Fe in normal as well as anemic raTs when compared wiTh conTrol animals. RaTs received equal amounTs of 59Fe and D-sorbiToI and iT was observed ThaT The amounT of radioiron absorbed was a direcT funcTion of D-sorbiTol concenTraTion. fig: Wissler g1.gl, (I954) sTudied The effecT of polyoxyeThylene sorbiTan monolauraTe (Tween 20), a faTTy acid polyoxyeThylene derivaTive of sorbiTol, on iron absorpTion. AdulT hamsTers fed a forTified bread raTion conTaing 5% Tween 20 absorbed greaTer amounTs of radioiron Than conTrol animals. Increases were noTed in The amounT of isoTope presenT in The cecum and large inTesTine, and resulTs suggesTed ThaT The excess iron was being absorbed largely in The cecum. The auThors posTulaTed ThaT The increased iron absorp- Tion was due To absorpTion from The large inTesTine in addiTion To The usual absorpTion from The small inTesTine. 23 Organic acids Groen g1.gl, (I947) showed ThaT The absorpTion of iron from closed loops of raT inTesTine was increased when soluTions of ciTric, succinic and malic acid were adminisTered. More recenTIy, Boddy and Will (I967) sTudied The effecT of succinic acid on The oral upTake of 59Fe on human subjecTs. The absorpTion of a physiological dose 0* 59Fe ferrous succinaTe was increased from 8.56% To l3.0% when succinic acid was given concomiTanle wiTh The ferrous succinaTe. According To Groen, The increase in iron absorpTion observed wiTh The adminisTraTion of organic acids was a consequence of The lowered pH. More iron would be in The ferrous form due To The lower pH and Thus more iron would be in an absorbable form. ProTein and Iron AbsorpTion DieTary_ProTein Level and Iron AbsorpTion Klavins §1_gl, (I959) showed ThaT young male albino raTs fed synTheTic proTein-free dieTs absorbed significanle less Iron Than pair-fed conTrols fed a dieT’ConTaining l8% casein. Also The hemoglobin levels of raTs fed The proTein-free dieT were lower Than Those of The conTrols. In conclusion, The auThors suggesTed ThaT a relaTionship exisTed beTween dieTary proTein level and iron absorpTion. More recenle These same workers sTudied The effecT of differenT dieTary proTein levels on iron absorpTion. Male albino raTs were again used. IT was found ThaT approximaTely l5 To l8% proTein was necessary for normal iron absorpTion. When lower levels of proTein were fed, iron absorpTion was impaired, and The auThors concluded ThaT The dieTary proTein level exerTed a definiTe quanTiTaTive effecT on 24 iron absorpTion (Klavins §I_§l,, I962). BhaTTacharya §1_gl, (I964), working in India, fed raTs dieTs conTaining 0 To l8% proTein. They also found ThaT iron absorpTion and hemoglobin levels were greale reduced in raTs fed proTein-free dieTs. The auThors considered ThaT a dieTary proTein level of 6 To 9% was necessary To mainTain adequaTe iron absorpTion, which is considerably lower Than ThaT recommended by Klavins T _1, (I962). Effecf of ProTein Source on Mineral AbsorpTion O'Dell and Savage (l957) briefly reporTed ThaT zinc in soy proTein was less available Than ThaT in animal proTein. Morrison and SareTT (l958) fed chicks dieTs conTaining eiTher soy, or casein and gelaTin, as The proTein source. Adding zinc To The soy dieT resulTed in increased growTh raTe. However, adding zinc To The casein dieT had no effecT on growTh raTe. Removal of supplemenTal zinc from boTh dieTs resulTed in reduced growTh raTes, alThough The effecT was mosT marked in chicks receiving The soy dieT. In view of This, The auThors concluded ThaT The soybean meal used in The experimenT conTained a facTor which mighT have impaired The availabiliTy of zinc for absorpTion. O'Dell and Savage (I960) sTudied The effecT of phyTic acid on zinc availabiliTy. Chicks fed a dieT conTaining casein and gelaTin as The proTein source had much beTTer growTh raTes Than chicks fed a soy proTein dieT. However, when a casein-phyTic acid complex and gelaTin was used as The proTein source, The growTh raTe was abouT The same as ThaT on The basal soy dieT. BoTh dieTs conTained abouT The same amounTs of phyTic acid, phosphorus and zinc. When zinc was added To The casein- 25 phyTic acid dieT, growTh raTe was considerably improved. Chicks fed a soy proTein-phyTic acid complex exhibiTed zinc deficiency sympToms and grew even more slowly Than chicks on The basal soy dieT, alThough The addiTion of IS ppm of zinc overcame The depressing effecT of The added phyTic acid. In conclusion, The auThors suggesTed ThaT The zinc in The isolaTed soy proTein was less available Than ThaT in casein. FurThermore, They sTaTed ThaT from The resulTs iT appeared The phyTic acid was involved in making zinc unavailable. AT The UniversiTy of California, Davis g1_gl, (I962a) carried ouT a sTudy To deTermine wheTher soybean proTein inTerfered wiTh The uTilizaTion of various Trace minerals. Chicks were fed dieTs conTaining Three levels of zinc, copper and manganese, wiTh and wiThouT eThylenediamineTeTraceTic acid (EDTA) along wiTh isolaTed soy as The proTein source. AT each level of mineral supplemenTaTion, performance was superior in The EDTA-supplemenTed groups. The auThors sTaTed ThaT EDTA is a sTrong chelaTing agenT and ThaT as such could form EDTA mineral complexes wiTh The various Trace minerals which were bound in The soy proTein. These EDTA mineral complexes would Then be available for normal absorpTion. No evidence was obTained ThaT EDTA pg5.§g_was growTh sTimuIaTing. More recenTIy, Edwards (l966) sTudied The effecT of proTein source on The absorpTion of 65Zn by The chick. IT was found ThaT chicks fed a casein-gelaTin dieT for 24 hours prior To dosing absorbed approximaTely l6% of an orally adminisTered dose of 65Zn. However, only 9% of The dose was absorbed by chicks on an isolaTed soy dieT. 65Zn was also given inTraperiToneally. In This insTance, There was only a slighT difference in reTenTion beTween chicks fed The differenT dieTs. Their 26 resulTs would appear To indicaTe ThaT soybean proTein is able To reduce The availabiliTy of free zinc for absorpTion. Several workers have also invesTigaTed The effecT of soy and casein proTeins on zinc availabiliTy and absorpTion in The pig. SmiTh g1__1, (I959) sTudied The effecT of differenT proTein sources on The zinc requiremenT of The growing pig. Pigs receiving isolaTed soy or soybean meal developed sympToms of parakeraTosis, buT no sympToms were observed in pigs receiving milk proTein dieTs. This occurred even Though The ToTaI dieTary zinc conTenT of The soy dieTs was higher Than ThaT of The milk proTein dieTs. The addiTion of zinc To The soy dieTs resulTed in significanT growTh increases (P<0.0l) and alleviaTion of parakeraTosis. The addiTion of zinc To The milk proTein dieTs did noT affecT growTh raTe. Thus iT would appear ThaT fon pigs, zinc in soy proTein sources is bound and unavailable for absorpTion. Oberleas _1__1, (I962) carried ouT experimenTs To deTermine The effecT of phyTic acid on zinc availabiliTy in growing swine. Over a 6-week period, pigs fed a basal soy proTein dieT conTaining 0.5% phyTic acid gained significanle less (P<0.05) Than pigs fed a basal casein dieT. The zinc conTenT of The Two dieTs was 25 and I4 ppm, respecTively. Pigs fed a casein dieT supplemenTed wiTh 0.7% phyTic acid gained significanle less (P<0.0l) Than pigs fed The casein basal dieT. However, when The casein-0.7% phyTic acid dieT was supplemenTed wiTh I00 ppm of zinc, gains were superior To Those on The casein-0.7% phyTic acid dieT and only sligthy less Than Those achieved on The basal casein dieT. Increasing The amounT of phyTic acid in The soy basal dieT To l.4% resulTed in significanle reduced daily gains (P<0.05) as compared To Those produced on The soy basal dieT iTself. 27 The growTh depressing effecT of added phyTic acid was correcTed by zinc supplemenTaTion, suggesTing ThaT The effecT of phyTic acid was To reduce The availabiliTy of zinc. This would explain The superior performance of pigs fed The basal casein dieT over pigs fed The basal soy, even Though The zinc conTenT of The soy dieT was nearly double ThaT of The casein dieT. Working wiTh The baby pig, Miller g1_ l. (I965) compared casein and soy proTeins wiTh regard To calcium, phosphorus and magnesium balance. Balance daTa showed ThaT pigs fed The soy dieTs excreTed larger amounTs of fecal phosphorus, calcium and magnesium Than pigs fed The casein dieTs. The auThors suggesTed ThaT This difference was due To The poor availabiliTy of The phyTaTe phosphorus in Thesoy proTein and The formaTion of phyTaTe complexes wiTh calcium and mag- nesium rendering These caTions less available for absorpTion. EffecT of ProTein Source on Iron AbsorpTion Davis eT al. (I962a) sTudied The effecT of soybean proTein on The uTilizaTion of Trace minerals by The chick. As previously sTaTed, The availabiliTy of zinc, manganese and copper was reduced in chicks fed The isolaTed soy proTein dieT. The availabiliTy of iron was also invesTigaTed in This same experimenT. DieTs conTaining 33.6, 43.6 and 58.6 ppm of iron were fed wiTh and wiThouT a supplemenT of 0.07% EDTA. AddiTion of EDTA To The dieTs did noT resulT in increased hemoglobin levels, indicaTing ThaT EDTA did noT increase The availabiliTy of The iron in The soy proTein. If an EDTA-iron complex was in facT formed, iT was noT reflecTed in Terms of changes In hemoglobin levels. 28 FurTher sTudies by Davis §I_gl, (l962b) also showed ThaT EDTA did noT increase The availabiliTy of The iron in soy proTein, Thereby con- firming The group's previous finding. They also sTaTed ThaT The iron in soy bean proTein was found To be available for growTh and hemoglobin formaTion. In addiTion, The availabiliTy of iron in soybean proTein and dried skim milk was compared, The 2 basal dieTs conTaining 23.7 and 28.0 ppm of iron, respecTively. DieTs conTaining added iron (40, 80 and I60 ppm) were also fed. Hemoglobin levels of chicks receiving The dried skim milk dieTs were significanle higher (P<0.0005) Than Those of chicks on The soy dieT. However, feed inTake and consequenTIy iron inTake was greaTer on The dried skim milk dieTs, and The auThors suggesTed ThaT This was The reason for The higher hemoglobin levels of chicks receiving The dried skim milk dieTs. IT was concluded ThaT The iron in isolaTed soybean proTein was approximaTely as available as The iron in dried skim milk. More recenT work on iron uTilizaTion and meTabolism in The chick was carried ouT by The same group (Davis g1_gl,, I968). The experimenT was designed To deTermine wheTher The phyTic acid conTained in soybean proTein inTerfered wiTh iron absorpTion. Chicks were fed eiTher an EDTA-washed soybean proTein dieT or a casein-gelaTin dieT, conTaining 24 and 25 ppm of iron, respecTively for I4 days. Casein and soy dieTs supplemenTed wiTh graded levels of iron (20 To l20 ppm) were also fed (see Table I). In general, chicks fed The soybean proTein dieTs had hemoglobin and hemaTocriT values equal To or higher Than Those of chicks receiving The casein-gelaTin dieT, and The auThors concluded ThaT: "no evidence was obTained ThaT The soybean proTein basal dieT reduced The uTilizaTion of iron. Thus, The possibiliTy ThaT The phyTic acid in The soybean proTein inTerfered wiTh The availabiliTy of iron was ruled ouT." 29 Table I. EffecT of proTein source on body weighT and hemoglobin levels in chicks (l4-day experimenfal period). Soybean dieT Casein-gelaTin dieT DieTary Iron Body wT. Hb,g/l00 ml Body wT. Hb,g/IOO ml ppm6 9 blood 9 blood 24 I36.2 4.5 l48.2 4.5 44 l55.4 6.6 I66.2 6.6 64 (50.9 8.4 I7l.2 7.9 84’ l64.9 9.3 I82.4 8.6 I24 l63.7 9.6 I73.9 8.9 I44 l62.3 9.0 l70.9 9.2 a The iron conTenTs of The basal soy and basal casein-gelaTin dieT were 24 and 25 ppm respecTively. SupplemenTal iron was added To give The higher iron levels. FurThermore, EDTA-washed soybean proTein was used in The Trial. Previously, Davis _1_Ql, (l962b) showed ThaT chicks fed an unTreaTed soybean proTein dieT conTaining 45.3 ppm of iron had an average hemo- globin level of 6.5 g/IOO ml of blood whereas chicks fed an EDTA- TreaTed soybean dieT (36.3 ppm of iron) supplemenTed wiTh l0 ppm of iron had a hemoglobin level of 4.8. Thus if would appear ThaT washing wiTh EDTA in some way reduced The availabiliTy of The iron in The soy. In view of This, iT could be assumed ThaT had unwashed soybean proTein been used in The I968 soy/casein comparison, growTh rafes and hemoglobin values mighT have been even higher Than Those quoTed (Davis §I_§l,, I968). Davis §1_gl, (l962a) sTaTed ThaT isolaTed soybean proTein conTains a componenT which combines wiTh zinc, manganese and copper and reduces The availabiliTy of These minerals. However, This was noT The case wiTh iron. In lighT of This sTaTemenT if is inTeresTing To noTe ThaT Vohra g1, I. (I965) demonsTraTed ThaT sodium phyTaTe formed complexes wiTh meTals in The following decreasing order: Cu++, Zn++, Ni++, Co++, Mn++, Fe++ and Ca++. 3O FriTz (I969) sTaTed ThaT The iron in isolaTed soy proTein was as available as ThaT in ferric ammonium ciTraTe, ferrous gluconaTe, ferrous fumaraTe and ferrous TarTraTe, and considerably more available Than The iron in ferrous carbonaTe and various ferric salTs. The repleTion of hemoglobin and hemaTocriT levels in raTs and chicks was used as The criTerion To deTermine uTilizaTion of iron in The various sources TesTed. In conTrasT To These previous reporTs, FiTch _I.gl, (I964) found ThaT 7 rhesus monkeys receiving purified dieTs conTaining isolaTed soybean proTein became anemic afTer 2 To 7 monThs. Previously, monkeys fed casein dieTs conTaining The same amounT of iron (2l0 ppm) had noT become anemic. STudies wiTh radioiron showed ThaT incorporaTion of 59Fe from a soybean proTein mixTure was approximaTely 50% as greaT as ThaT from a casein 59Fe mixTure. IT should be noTed however, ThaT only one monkey was used in This sTudy. Thus, from liTeraTure reviewed, iT would appear ThaT in general, The iron in soybean proTein is available for absorpTion and uTilizaTion. PepTides and Iron AbsorpTion Mellander (I955) hypoThesised ThaT iron may combine wiTh pepTides and be absorbed in This form. He noTed ThaT pepTides complex wiTh iron and appear To acT as effecTive chelaTing agenTs. An iron-pepTide complex conTaining 20% iron given orally To humans was absorbed efficienfly, as judged by increased serum iron levels. Indian workers showed ThaT The ingesTion of acid or enzyme hydrolysaTes of casein and iron Increased The body iron in raTs. They also suggesTed ThaT pepTides or oTher 3| proTein degradaTion producTs acTed as chelaTing agenTs and ThaT pepTides acTed as vehicles for The TransporT of iron Through The gasTroinTesTinal mucosa (BhaTTacharya and Esh, I964). Amino Acids and Iron AbsorpTion Rummel and Camdon (I956) sTaTed ThaT amino acids are good chelaTing agenTs and showed ThaT an iron and alanine chelaTe, given orally, increased serum levels considerably more Than ferrous sulfaTe alone. CysTeine Groen ei__l. (I947) noTed ThaT cysTeine increased iron absorpTion from closed loops of raT small inTesTine. This effecT could be due boTh To The reducing properTies of The sulfhydryl group of cysTeine and also To iTs chelaTing abiliTy. MeThionine Kaufman _1_gl, (l966) fed meThionine-deficienT dieTs To raTs for 4 weeks. Compared wiTh conTrols, These raTs developed anemia and Their ToTaI body Iron levels decreased, due To a decrease in iron absorpTion or reTenTion. The low hemoglobin levels could also have been a direcT consequence of The meThionine deficiency, as hemoglobin iTself conTains a small percenTage of meThionine. This same group (Klavins gi_gl,, I963) also sTudied The effecT of excess meThionine levels on body iron levels and hemaTological parameTers. IT was found ThaT excess meThionine feeding also produced anemia. To explain This resulT, The auThors posTulaTed ThaT since meThionine inhibiTs hisTidine absorpTion (Taylor T I., I959) and, as hisTidine is The mosT IimiTing amino acid in hemoglobin synThesis (Borsook e1_gl., I957), The anemia observed was 32 a consequence of The unavailabiliTy of hisTidine due To The high level of meThionine fed. OTher amino acids Kroe §1_gl, (I963a) showed ThaT raTs perfused wiTh soluTions conTaining 59Fe and hisTidine absorbed more iron Than raTs perfused wiTh The isoTope alone. In comparisons involving oTher amino acids, however, hisTidine had relaTively liTTle effecT on increasing iron absorpTion. Kroe e1_gl. (l963b) compared The effecTs of various amino acids on iron absorpTion from The raT gasTro inTesTinal TracT, as measured by The appearance of 59Fe in The serum and liver. GluTamine, gluTamic acid and asparagine gave The greaTesT increases in blood 59Fe values. MeThionine, proline, serine and phenylalanine produced a moderaTe increase in iron absorpTion, and hisTidine supplemenTaTion increased Iron absorpTion IeasT of all. More recenle The same group (Kroe g1.gl., I966) again showed ThaT iron absorpTion was greaTer wiTh gluTamine supplemenTaTion Than wiTh hisTidine, regardless of pH. In conTrasT, Van Campen and Gross (I969) found ThaT hisTidine and lysine increased 59Fe absorpTion from ligaTed raT duodenal segmenTs, whereas gluTamic acid, gluTamine, meThionine and glycine did noT. In This insTance, ferric iron was used, whereas in previous sTudies The ferrous form was prefered. This facT may parle explaln The difference in resulTs. FurThermore, The auThors noTed ThaT Their findings were consisTenT wiTh The hypoThesis ThaT amino acid-iron chelaTes are formed and subsequenle absorbed. In conclusion, iT is possible ThaT The differences in iron absorpTion associaTed wiTh differenT proTein sources may in parT be a consequence of Their amino acid composiTion. III. EXPERIMENTAL PROCEDURE lnTroducTion Two Trials were conducTed To sTudy The effecT of proTein source on The iron requiremenT of The baby pig. Two proTein sources were used in conjuncTion wiTh Three levels of dieTary iron; four pigs were alloTTed To each TreaTmenT group, Thereby giving a 2x3 facTorial. General ConducT of ExperimenTs The Two Trials involved a ToTal of 48 pigs, all from The UniversiTy herd. In Trial I, 20 Yorkshire and four Hampshire pigs were used; in Trial 2, pigs were all of The Yorkshire breed. The experimenTal procedure was The same In boTh Trials unless oTherwise sTaTed. Pigs were Taken from The sow af 2 To 7 days of age and placed in individual sTainless sTeel rearing cages equipped wiTh sTainless sTeel feeders and wafer Troughs. Room TemperaTure was mainTained aT 20°‘C for The duraTion of The Trial. The pigs were weaned To a dry purified dieT (Table 2). lnTake was encouraged by placing small amounTs of feed in The animals' mouTh. The pigs readily adapTed To The dry feed and no problems wiTh adapTaTion were encoun- Tered. The pigs were fed a low iron dieT (I5 ppm) for several days To depleTe Their iron reserves afTer which four pigs were alloTTed To each TreaTmenT group on The basis of sex, weighT and liTTer. The experimenTal dieTs conTained eiTher purified casein or isolaTed soy as The proTein source. The soy proTein dieTs were supplemenTed wiTh 0.3% DL-meThionine. A basal dieT, basal plus 50 ppm of iron and basal 33 Table 2. ComposiTion of experimenTaI dieTs. Caseinl Soy2 S % Casein 3O - Soy - 30 DL-MeThionine - 0.3 air-Cellulose} 5 5 Lard 5 5 Cerelose4 5| 50.7 Mineral mixTure5 6 6 FaT-soluble viTamins in corn oil6 I l Wafer-soluble viTamins in waTer6 2 2 I High ProTein Casein, General Biochemicals, Chagrin Falls, Ohio. g Soya Assay ProTein, General Biochemicals, Chagrin Falls, Ohio. 4 Solka Floc, Brown Company, Chicago, Illinois. Cerelose, Corn Producfs Company, Argo, Illinois. See Appendix Table l. 6 See Appendix Table 2. 35 plus l00 ppm of iron were produced, using FeSO4-2H20 for supplemenTary iron. 0n compleTion of Trial I if was found ThaT The iron conTenT of The soy proTein was considerably greaTer Than The assumed value. Consequenle The iron conTenT of The soy dieTs was greaTer Than ThaT of The casein dieTs. In view of This, in Trial 2 The amounT of supplemenTal iron in The casein dieTs was increased in order ThaT The casein and soy dieTs would conTain equal amounTs of iron aT The Three TreaTmenT levels. The analyzed iron conTenT of The dieTs is shown in Table 3: Table 3. DieTary iron levels (ppm). Basal Basal+ 50gppm Fe Basal+l00_ppmAFe Casein Soy Casein Soy Casein Soy Trial l 45 73 88 I37 l52 l89 Trial 2 IOI 95 I48 I47 l89 I89 Blood was Taken from The anTerior vena cava iniTially and aT The conclusion of each Trial for deTerminaTion of blood and serum consTiTuenTs. Pigs were fed 2g libiTum and had free access To wafer, which was changed Twice daily. All feed was weighed ouT daily and individual feed consumpTion was recorded. Pigs were individually weighed weekly for The duraTion of The Trial, following which They were reTurned To The UniversiTy herd. Pigs were kepT on Trial I for 29 days and for 35 days in Trial 2. Mineral balance sTudies were conducTed during The final 2 weeks of boTh Trials. Two pigs from each TreaTmenT group were selecTed on The basis of equivalenT weighT and placed in individual meTabolism cages. Pigs were removed from The cages Three Times daily and individually 36 fed an amounT of food and waTer which could be consumed wiThin a 5 To I0 minuTe period. Following This, The pigs' mouThs were wiped clean To avoid conTaminaTion of excreTa. The pigs were Then reTurned To The cages. AfTer a 3-day adjusTmenT period, fecal and urine collecTions were made over a 3-day period. Feces were separaTed from urine by means of a fine screen placed above The collecTion funnel. Where possible, consTanT daily feed inTakes were mainTained ThroughouT The balance period. Feces were oven dried for 24 hours, weighed, ground and sTored in sealed plasTic conTainers. Urine was collecTed in polyeThylene conTainers and acidified wiTh 6N HCI. Following The collecTion period, The urine volume was recorded and ICC ml aliquoTs were Taken and sTored in acid-washed polyeThylene boTTles.aT 3° C. During each Trial, one pig on The basal casein dieT wenT off feed, IosT weighT became weak and was consequenle killed. PosT morTem informaTion was noT obTained on pig 57-5 which died during The firsT Trial. A posT morTem examinaTion of pig I7-7 which died during The second Trial revealed evidence of encephalomalacia and meningiTis. HemaTological ParameTers Hemoglobin Hemoglobin was deTermined by The cyanmeThemoglobin meThod of Crosby §I_gl, (I954). A Coleman Junior II specTrophoTomeTer was used for opTical densiTy deTerminaTions. 37 HemaTocriT HemaTocriT was deTermined by The micro meThod (McGovern §1_g1,, I955). Blood samples were cenTrifuged for 5 minuTes aT l0,000 RPM in an lnTernaTional "HemacriT" cenTrifuge. EryThrocyTes EryThrocyTes were counTed in duplicaTe from a single filling of a "zero error" Hellige pipeTTe, using an improved Neubauer counTing chamber. The diluenT used was 0.85% NaCI. ReTiculocyTes Four drops of meThylene blue were mixed wiTh an equal amounT of blood and allowed To sTand for I0 minuTes. Following This, duplicaTe Thin smears were made, allowed To dry and Then sTored for IaTer counTing. ReTiculocyTes were enumeraTed per IOOO eryThrocyTes and expressed as a percenTage. AnalyTicaI Procedures feed. A weT ashing procedure was used. A I 9 sample was placed in a 250 ml Phillips beaker and 60 ml of concenTraTed HNO3 were added. This digesTion mixTure was heaTed on a hoT plaTe To near dryness and allowed To cool. Seven ml of concenTraTed perchloric acid were added and digesTion conTinued, again To near dryness. AfTer cooling, samples were diluTed To consTanT weighT wiTh deionized disTilled waTer. STandards and blanks were prepared in an idenTical manner. Iron conTenT was deTermined by aTomic absorpTion specTrophoTomeTry, using a Jarrell-Ash model 82-5l6 specTrophoTomeTer equipped wiTh a 38 HeTco ToTal consumpTion burner. Samples were aspiraTed inTo an air-hydrogen flame. An absorpTion wavelengTh of 2480-5 2 was used. Feces Fecal iron was deTermined by an idenTical procedure, excepT ThaT a sample weighT of 0.5 g was used. Urine For iron deTerminaTions, undigesTed and undiluTed samples were used and concenTraTions were deTermined using aTomic absorpTion specTrophoTomeTry. Serum DeTerminaTions Blood samples from The pigs were collecTed in acid-washed TesT Tubes and allowed To coagulaTe. Following removal of The cloT, samples were cenTrifuged aT 550 g for IS minuTes. The serum was Then Transfered To acid-washed vials for 5° C sTorage. Serumgprofein analysis ToTal serum proTein was deTermined using a modified Lowry procedure (Miller, I959). ElecTrophoreTic separaTIon of serum proTeins was achieved using agar sTrips in a modified Beckman-Spinco Durrum cell. STrips were scanned using a Beckman RB AnalyTrol densiTomeTer. Serum samples were Then frozen and sTored aT -I0° C unTil furTher analyses were performed. Serum iron Serum iron concenTraTion was deTermined by aTomic absorpTion specTrophoTomeTry, again using a wavelengTh of 2480'5 2. Serum 39 samples were diluTed l:l wiTh deionized disTilled waTer prior To serum iron deTerminaTion. ToTal iron-binding capaciTy The procedure developed by Olson and Hamlin (I969) was slighTIy modified and used To deTermine ToTal iron-binding capaciTy. Equal volumes (0.5 ml) of serum and a ferric chloride soluTion (5 ppm iron) were mixed and allowed To sTand for 5 minUTes. Following The addiTion of 50 mg of magnesium carbonaTe, samples were mixed four Times during a 30 minuTe period, cenTrifuged and 0.5 ml of The supernaTanT Trans- ferred To anoTher TesT Tube. One ml of 20% TCA was added To The supernaTanT, and The Tube heaTed aT 900 C for IS minuTes. Following cooling and cenTrifugaTion, The iron conTenT of The supernaTanT was deTermined by aTomic absorpTion specTrophoTomeTry. Hemoglobin iron Because of hemolysis in cerTain serum samples, iT was necessary To correcT for The hemoglobin iron presenT in These samples. The specTrophoTomeTric meThod for quanTiTaTing hemoglobin in serum developed by HunTer e1_al (I950) was used. STaTisTical Analysis The daTa were analysed by analysis of variance and by The muITiple range TesT of Duncan (Bliss, I967). IV. RESULTS AND DISCUSSION Trial l Pig performance daTa are presenTed in Table 4. In general, a posiTive linear effecT was noTed wiTh an increase in The iron conTenT of The dieTs, irrespecTive of The proTein source. Differences in average daily food inTake approached significance (P<0.07) wiTh regard To dieTary iron level. HemaTologicaI daTa are presenTed in Table 5. Regardless of proTein source, hemaTocriT values increased wiTh increasing dieTary iron level (P<0.00I). The effecT of proTein source on hemaTocriT values approached significance (P<0.07). Hemoglobin levels similarly significanTIy (P<0.00l) increased wiTh increasing dieTary iron level. The effecT of proTein source on hemoglobin levels was noT significanT. As judged by hemoglobin levels, pigs on The 45 ppm casein and 73 ppm soy dieTs were anemic, having hemoglobin levels of less Than 8 g/IOO ml. This is noT unexpecTed as The AgriculTural Research Council of GreaT BriTain (I967) considered ThaT a dieTary level of 60 ppm was necessary To produce a hemoglobin level of 8 g/IOO ml. This is The same level as suggesTed by MaTrone eT al. (I960) for baby pigs fed a forTified cows' milk dieT. PickeTT §1_ I. (I960) using a dried skim milk semi-purified dieT found ThaT normal hemoglobin and hemaTocriT levels were obTained wiTh a dieTary level of 80 ppm or more. Ullrey §I_gl, (I960a)recommended a level of I25 ppm for pigs fed a synTheTic casein-Type dieT. Conse- quenle, The Type of dieT fed influences The oral iron requiremenT. 4O 4| .cmoe 65+ +0 Locum ucmocm+m _ em.o ec.o 4N.o .e.o _..o oe.o es.o ec.o ec.o ne.o Nm.o aoo+\c_eo .m.o o_.o no.0 0N.o no.0 mm.o mN.o NN.o m~.o em.o s_.o ex .aooe >__na m>< oh.o em.o m_.o em.o eo.o mN.o e_.o c..o e_.o om.o oo.o ex .a_ee >:eo e>< cm.o we.o c_.o RN.o em.. e.e m.e e.c 4.5 e.e e.e as ..+; _oc_e ee.o om.o No.0 no.0 o_.o _.N _.N _.~ _.~ o.~ _.N mx ..+3 _e_+_a_ coc_x.+oce ._aem coc. .eoco _wmn em. em. me mm. me me see ._o>o_ coc_ Ao:_m> av mecmo_+_cm_m NOm c_ommo OOLJOm :_o+oLm _m_c+ .n+nn oocmEco+Lmo m_a uoN_cmEE:m .e.o_sbe 42 .A_o.0vmv 00 .._0.0vmv uo .A.o.ovmv an .A_0.0v&v um N30.0!3 mm:_n> Lace +000. “.00.0v¢v mo:_o> emcz+ +mmo. “Amo.ovmv mo:_m> 03+ +mno_ “.mo.0vac es_o> shoe. cmc+ Le+mocm >_+cmu_+_cm_m 0 cnc+ Lo+mocm >_+cnu_+_cm_m o cng+ Lm+nocm >_+cnu_+_cm_m a ccc+ Lo+mocm >_+cou_+_cm_m m .cmoe 05+ +0 Loccm eunucm+m p .0.0 0N.0 e¢.0 0N.0 m¢.0 v._ n._ n._ ¢.N <._ 0.N .mc_m 00.0 e0.0 0N.0 em.0 00.0 0.m e.n N.N _.m >.N m.N _m_+_c. mo+>ooLc+>Lo +0 m .mo+>oo_:o_+om 00.0 No.0 00.0 no.0 N0.n 065.00 m_.>¢ N.mn nm.mv N.0¢ _.en .mc_m 00.0 0e.0 00.0 .m.0 00... _._0 0.0m 0.¢n ..mn m..0 m._n _n_+_c_ mcoLo_E o_a:u .oEa_o> Lm_:um:ocoo coo: n_.0 .0.0 N~.0 mn.0 me.0 NN.0 0N.0 mn.0 00.0 00.5 00.0 .mc_m v_.0 00.0 00.0 00.0 00.0 ev.¢ en.n Nu.e Nm.m n0.e .0.¢ _m_+_c_ mee\00. .me+>ooLc+>cm .m.0 0N.0 N0.0 00.0 nN.. m.m~ _.m~ n.0N 0.5m 0.0N ..0N .mc_m N0.0 .N.0 no.0 00.0 0n.0 0.>~ 0.0N ~.nm n.0N N.0N _.5N .o_+_c. u .com+mc+cooc06 c_no_0osoc Lm_:om:auou coo: mm.0 nv.0 00.0 0_.0 00.0 000.0 mn.0 ¢.n mc_.m oe.0 v.0 _nc_m 00.0 m~.0 mm.0 NM.0 00.0 m.n m.n n.w n.0 m.w m.» _n_+_c_ coo_a .2 oo_\e .c_ao_mosox eN.0 00.0 00.0 50.0 nm._0.anv.¢n 000.0N omm.0mn.nno.nn 000.0N 0.0N .mc_m 00.0 __.0 0N.0 mn.0 00.. 0.0m 0.~N n..m 0.0m n.0N 0.0m .m,+_c. m .+_Loo+meoz coc_x.+oca ._aem coc. .eoce .mmu es. pm. me Ne. me me sea ._o>o_ coc. I~02_e> my oocmo_+_cm_m INOm c_omno oouaom c_o+oLm ._ .o_c+ .neeo _oo_mo_o+oso: .m o.noh 43 Differences in mean corpuscular hemoglobin concenTraTion and eryThrocyTe counTs beTween TreaTmenT means were noT significanle differenT. These values were similar To Those obTained by Ullrey _;[._L. (l960a). Mean corpuscular volume increased significanle (P<0.00l) wiTh increasing iron levels on boTh proTein TreaTmenTs. FurThermore, The values for pigs receiving The soy dieTs were sig- nificanle (P<0.03) greaTer Than Those of pigs receiving casein. Differences in reTiculocyTe counTs were noT significanT, alThough for each TreaTmenT, final values were lower Than lniTial values. Serum iron values and oTher relaTed parameTers are shown in Table 6. Regardless of The proTein source, serum iron values in- creased wiTh increasing levels of supplemenTal iron (P<0.00l). However, There were no significanT differences found beTween TreaT- menT means wiTh reference To ToTaI and unbound iron-binding capaciTy. Transferrin saTuraTion decreased wiTh decreasing dieTary iron (P<0.00l). ConsequenTIy, The more anemic animals had The IowesT Transferrin saTuraTion. ResulTs of The serum proTein analyses are presenTed in Table 7. Increasing dieTary iron levels resulTed in increasing a-globulin levels (P<0.05). The balance daTa from Trial I are shown in Table 8 and figure I. Chemical analysis of The waTer used in The Trial indicaTed The presence of no measurable amounTs of iron. Consequenle waTer consumpTion daTa were noT included in The Table. SignificanT differences were observed in food inTake. This was a consequence of The exTremely low inTake of The pigs receiving The 45 ppm casein dieT. Differences in The daily iron inTake were also significanT (P<0.00I) due To The higher amounTs 44 .A.o.0vmv 00 .A.o.0vmv 00 “.00.0v00 mo:.0> 03+ +000. c00+ 00+00L0 >.+c0u.0.c0.m 0 “.00.0vmv 0:.0> +m00. c00+ co+00u0 >.+c00.+.c0.m 0 .c0oE 00+ +0 L0LL0 0L00c0+mib 0N.0 0>.0 .0.0 N¢.0 00.0 000.00 00.00 0.00 000.vn 00..» 0.00 .00.0 nm.0 0..0 00.0 00.0 00.0 0.00 0.00 0.00 0.00 ...n 0.00 .0.+.c. m .co.+0ca+0m c.cco+mc0ck N0.0 mn.0 00.0 .0.0 00... 00 Me 00 00 00 e0 .0:.m 00.0 .0.0 0e.0 ~0.0 00.00 mm. 00 .0 00. .0 .0 .0.+_c. Eauom .e 00.\0oe .00.: 00.0 0e.0 0..0 00.0 00.0w mnm 0mm N0. .0N 0.N 0.N .00.; n..0 00.0 0..0 00.0 .0.0N N0~ 00w eNN new .mN 00. .0.+.c. Eacom .E 00.\0oe .00.h 00.0 0N.0 00.0 N0.0 00.0. 00>. 00. RN. 0000. 00. 0.. .00.0 e0.0 00.0 0..0 .0.0 e0.0. 00. e0. 00. 00. 00. he. .0.+.c_ Eacom .E 00.\0ue .c00. Eacmm aoc_x.+oce ..aom coc. .eoca .umn as. an. 05 mm. 00 me see ._o>o. coc. .0:.0> 00 00c0o.+.co.m >00 c.0000 oucaom c.0+0cm .. .0.L+ .c0.+0c:+0m c.cco+mcmc+ 0:0 >+.00000 00.00.0Icoc. 0:20003 0:0 .0+0+ .coc. Eacom .c o_ape ..00.0v0+ m0:.0> 03+ +000. 000+ L0+0000 >.+c00.+_00.m 0 .0005 00+ +0 L0LL0 nc0uc0+m C 00.0 .0.0 .N.0 00.0 .5.. 0... 0.0. 0.0 ..0. 0.0 0.0 .0:_u 0N.0 00.0 00.0 NN.0 0..N ..0. 0.NN N..N 0.0N 0.0m ..0N .0.+.c_ c.0+0+a Escom .0+0+ +0 0 .:__:00_0I> Enumm 05.0 00.0 00.0 00.0 05.0 5... ..N. ..N. 5.N. 0.0. N.<. .0c_m 05.0 Ne.0 00.0 00.0 00.. 0.0. ¢.N. 0... 0.0. 0.0. 0.0. .0.+_c. c.0+oca Escmm .0+0+ +0 0 .c..:00.0i0 Eacmm N0.0 00.0 00.0 .0.0 05.. 0..00 0.5N 0.0m ..Nn N.00 0.5N .0c_m 00.0 N0.0 0..0 N_.0 00.. 0.N0 v.0N 0.00 0.5N N.5N 0.00 .0.+.c. c.0+oca 5:000 _0+0+ +0 0 .c..:00.0ia Esc0m N0.0 .0.0 e0.0 0..0 00.0 0.00 0.00 5.00 0.00 0.00 ¢.Ne .0c.u 00.0 00.0 00.0 05.0 00.. 0.00 5.50 N.N0 N.00 0.0m 0.N0 .0.+_c. c.0+0ca Eac0m _0+o+ +0 u .c.E:0.0 Eac0m 00.0 00.0 00.0 5N.o 00.0 «.0 N.0 0.5 0.5 0.5 0.0 .0c.m 5N.0 NN.0 00.0 50.0 0N.0 N.0 5.0 0.0 0.0 0.0 5.0 .0.+.c. Escom .e 00.\0 .c.0+0ca Esc0m .0+0+ aoc.x.+oca ..aom cop. .+oce .mmh em. en. 05 mm. 00 me see ..oso. coc_ .0:.0> 0+ 00:00.+.c0.m >00 c.0000 00L=Om c.0+0c0 .. .0.L+ .mom>_0c0 :.0+0ca Eau0m .5 0.00h 46 .A.o.0vm+ 00 0.00.0400 nos.e> cea+o _.e cpc+ 00+0000 >.+000.+.00.m 0 .._o.oVac 44 0.00.0.0. mes_e> cso+ +hoo_ co0+ co+eece >_+ceo_+_ce_m a .._o.ov00 oo 0.00.040. nos_e> oo00+ +neo_ 000+ co+eoce >_+ceo_+_cm_m o .._o.0v0. as 0.00.0v00 nos.e> oz+ +eoo_ 040+ co+eoce >_+apo_+.ce_m a .._o.ove. he 0.00.0v00 os_e> +meo_ ae0+ ce+nece >_+aeo_+_ae_m e .+005+000+ L00 00.0 03+ N .0005 00+ +0 00000 000000+m.0 .m.z 00.0 .m.z n_.N_ mm owe 0N one 40 mm m .co.+co+oc o0 .m.z 00.0 .m.z ek.m o.aae.m~o.aam.m~ 4.0 o.aan.m~ _.__ ~.~ as .co_+co+oc e0 .m.z .m.z .m.z 00.0 4.0 4.0 4.0 4.0 _.o 4.0 00 .e0 scpc_cs .m.z 00.0 00.0 44.N om.om o.o_ o.~_ 0.N_ o.e ~.4 ma .oe .ooo0 00.0 00.0 00.0 +0.0 eom.04 oom.4n can.e_a.ooo.mna.eo_.om 0.0 as .oxo+c_ o0 5..00 .0000.00 00 _o.o 00.0 .o.o mo.o eem4~ seemm enema ebomm epeNN 00. Ne .oxb+c_ coo. >._ho coc_x.+oca coc_ .+oce _mmh em. Am. ms ~m_ 00 04 see ..oso. coc_ ~0:.0> a. 00000.+.0m.m 500 0.0000 000000 0.0+0Lm ._ .o_c+ .o+oo oucn.om .0 o_0n+ 47 .. _0.0+ .0000.00 000. 00 .0>0. 000. 000 000300 0.0+000 >00+0.0 +0 +00++m FIL. 22:30: a 2.... .20.: >¢¢hm§ 2. ~0— 2.003 8 0+ .. 0030.0 0. W m cw N no ww W ca 8 H nu ww nu In 3 on 48 of iron in The Three soy proTein dieTs. Fecal iron increased wiTh increasing iron levels (P<0.05). Also, fecal iron oquuT was greaTer (P<0.05) on The soy dieTs Than on The casein. The reTenTion daTa are difficulT To inTerpreT. In general, anemic animals reTain more iron, on a percenTage basis, Than normal animals. In This insTance, however, pigs receiving The basal soy and casein dieTs reTained less iron on a percenTage basis Than pigs on The oTher four TreaTmenTs. Hendricks (I967) carried ouT iron balance sTudies wiTh baby pigs receiving 40% of eiTher casein or soy as The proTein source. PercenT iron reTenTion on The casein dieT which con- Tained l06 ppm of iron, was 35%. ReTenTion on The soy dieT (I94 ppm of iron) was 50%. These values are somewhaT differenT from Those given in Table 8. Because of The unequal iron levels in The differenT dieTs iT is difficulT To make a definiTe sTaTemenT in relaTion To The effecT of The proTein source on iron absorpTion and uTilizaTion. Some conclusions may be drawn from daTa of pigs on The |52 ppm casein and The I37 ppm soy dieTs, as These Two dieTs approached equiv- alence in Terms of iron conTenT.. No significanT differences were observed in final weighT or hemaTocriT, hemoglobin and eryThrocyTe values. Also The iron reTenTion percenTages for The Two TreaTmenTs were almosT idenTical. Consequenle if can be sTaTed ThaT under The condiTions of The Trial, aT The level of iron supplemenTaTion menTioned above, The proTein source had no significanT effecT on iron absorpTion and uTilizaTion. Trial 2 Pig performance daTa are shown in Table 9. Average daily gain increased wiTh increasing levels of dieTary iron (P<0.05) and 49 .x_o.ovac as “.00.0v00 003.0> N +000. 000+ 00+0000 >.+00u.+.00.m 0 .0005 00+ +0 00000 u00000+m . 00.0 04.0 .o.o N_.o 40.0 a++.o 00.0 00.0 0+5.o 00.0 00.0 cooe\c_ho 00.0 +4.0 54.0 eo.o no.0 _n.o em.o 5N.o +~.o 00.0 mm.o 0. .aoe0 >:ea m>< 05.0 +0.0 00.0 00.0 No.0 asmm.o 00.0 0..0 0.0.0 4_.o 4..o ex .a_ee >._ea e>< 0+.o N+.o 0..0 0..0 No._ 4.0. +.e 0.0 e.e 0.5 0.5 00 ..+; .ec_0 00.0 04.0 ao.o No.0 40.0 +.N +.N +.~ 0.0 +.N 5.0 a. ..+3 .n_+_c_ co0_x.+o00 ..aem coc. .+000 .000 em. 54. me em. 04. _o_ 000 ._o>o_ co0_ .03.0> 0. 00000.+.00.m 500 0.0000 000300 0.0+o00 .N .0.0+ .0+00 0000500+000 0.0 00~.005530 .0 0.005 50 differences beTween proTein source approached significance (P<0.06). This growTh difference was a consequence of higher food inTake by pigs on The soy dieTs. This difference approached significance (P<0.09). IT is possible ThaT The higher inTake of The soy dieTs was relaTed To The palaTabiliTy and physical TexTure of The Two dieTs. The casein dieTs Tended To adhere To The feeder and The sides of The pens more readily Than The soy dieTs. Thus The more adhesive naTure of The casein dieTs may have been a facTor in reducing The inTake of These dieTs. Feed efficiency also increased wiTh increasing iron levels (P<0.0l). As can be seen from Table l0, final hemaTocriT and hemoglobin values were significanle differenT and reflecTed changes in The iron conTenT of The dieTs. Pigs on The soy dieTs had significanle higher hemaTocriT and hemoglobin values (P<0.0l) Than pigs receiving The casein dieTs. The final hemoglobin values in The second Trial were somewhaT lower Than Those observed in The firsT Trial, even Though The iron levels of The Three casein dieTs had been increased. These low final values may have been due in parT To The facT ThaT The iniTial hemaTocriT and hemoglobin values of pigs on Trial 2 were lower Than Those of pigs on Trial l, and consequenle These pigs were more anemic and would require more iron To repleTe Their Tissues. FurThermore, in boTh Trials, supplemenTal iron was provided as F0504.2H20. BoTh MaTrone £1.01, (l960 and Ullrey gi,§l, (l960a) used F0504.7H20 To pro- vide supplemenTal iron. These workers also fed a liquid dieT, whereas a solid dieT was used in This sTudy. IT is possible ThaT The iron sup- plled as FeSO4.2H20 was in a less available form as compared To FeSO4.7H20. ConsequenTIy, less iron would be available for absorpTion and uTilizaTion. 5| .A.0.0vmv 00 “A00.0v00 00:.0> 000+0 ..0 000+ 00+000m >.+000.+.0m.m .Am0.0vmv 00:_0> 020+ +000. .Am0.0v00 00:.0> 0000+ +000. 000+ 00+000m >.+000.+.0m.m .Am0.0v00 00:.0> 03+ +000. 000+ 00+0000 >.+000.0.00.m ..m0.0v¢v 0:.0> +000. 000+ 00+000m >.+000.0.0m.m 000+ 00+000m >.+000.+.0m.m 10.0000 .0005 00+ +0 00000 000000+Mlh n<.0 00.0 .0.0 0m.0 Nm.0 0.. 0.N 00.0 0.n N.~ 00.n .00.0 0N.0 00.0 00.0 .0.0 +0.0 0.0 n.~ 0.n n.N 0.n 0.. .0.+.0. 00+>0000+>00 00 u .00+>00.:0.+0m mm.0 00.0 .0.0 00.0 ~0.N 0+.0m 0.0M N.0n 0.00 0.0n 0.00 .00.0 +0.0 N¢.0 00.0 +0.0 00.0 v.mm m.mm 0.0m 0.nm 0.0m 0.0m .0.+.0. 00000.5 0.000 .05:.0> 00.30000000 0002 00.0 mm.0 00.0 00.0 mn.0 000.0 0m0.0 00.m m¢.m .m.m 00.0 .00.0 +0.0 0N.0 00.0 mm.0 0N.0 mm.< 00.0 00.0 00.0 0~.¢ N¢.¢ .0.+.0. m5530. .00+>0000+>0m 00.0 _n.0 00.0 00.0 _m.0 0N.mN m.m~ v.0N 0..0N ¢.n~ m.m~ .00.0 no.0 Nn.0 00.0 N..0 mm.0 n.0m 0.0N 0.0N ..on 0.0m ..mN .0.+.0. u .00.+00+000000 0.00.00500 00.00000000 0002 0N.0 NN.0 00.0 .0.0 no.0 000.0 m.0 0.0 0..0 0.0 N.m .00.0 00.0 No.0 00.0 00.0 00.0 0.0 0.0 N.0 0.0 ..m 0.0 .0.+.0. 000.0 .2 00_\0 .c.go.0oemz 0..0 0N.0 .0.0 .0.0 00.. 00n.nn 0.0m N.nN m.mN ...N 0.N~ .00.0 .0.0 .0.0 0n.0 v0.0 00.. v.0N 0.0N 0.0N 0.0N m.mN n.mN .0.+.0. N .+.000+050I :00.x.+o00 ..000 000. .+o00 .00“ 00. 04. ma 00. 04. .0. 000 ..o>o. 000. .0:.0> a. 00000.+.0m.m >00 0.0000 000000 0.0+000 .N .0.0+ .o+ou .oo.0o.o+oeox .0. 0.000 52 Mean corpuscular hemoglobin concenTraTion increased wiTh increasing levels of dieTary iron (P<0.00l). EryThrocyTe counTs from pigs receiving soy dieTs were significanle (P<0.002) greaTer Than Those from pigs receiving casein dieTs. Mean corpuscular volume increased wiTh increasing dieTary iron levels (P<0.0l), whereas reTiculocyTe counTs decreased wiTh increasing dieTary iron levels (P<0.0l). Serum iron values and oTher relaTed parameTers are shown in Table II. Serum iron values increased wiTh increasing levels of dieTary iron (P<0.0l). ToTal iron-binding capaciTy also increased wiTh in- creasing dieTary iron levels (P<0.002). Anemic animals usually have higher TIBC values Than normal animals (Ullrey §1_gl,, l960a). in This insTance, The reverse occurred. As in Trial l, percenT Transferrin saTuraTion decreased wiTh decreasing dieTary iron levels, alThough differences were noT significanT. The Transferrin saTuraTion values were smaller Than Those in Trial I, again a reflecTion of The low iron sTaTus of The pigs in Trial 2. DaTa from The serum proTein analyses are presenTed in Table l2. Serum albumin levels increased wiTh increasing dieTary iron level (P<0.02) whereas serum a-globulin levels decreased (P<0.02). AlThough There was no significanT effecT of iron level on B-globulin levels, There was a negaTive linear effecT of dieTary iron on The Transferrin- conTaining a-globulin fracTion in boTh Trials. DaTa from The balance Trial are shown in Table l3 and figure 2. The daily iron inTake reflecTed The differenT iron conTenT of The dieTs (P<0.00l). Fecal iron levels increased wiTh increasing dieTary iron levels (P<0.05) and fecal iron oquuT was greaTer from pigs receiving The casein dieTs. Iron reTenTion increased wiTh .Am0.0vmv 000.0> 000+ +000. 000+ 00+0000 >.+000.+.00.m 0 ...0.0v00 as 0.00.0v0. 00.0) +000. 500+ 0o+mm00 >.+coo.+_cm.0 a .0005 00+ +0 00000 000000+ml. 00.0 00.0 0..0 00.0 00.0 0.00 0.00 0.0m m.mm 0.00 0.0m .00.0 «0.0 0..0 m0.0 00.0 00.m ..nm N..m m..n n.0N m._n 0.0m .0.+.0. u .0o.+000+00 0.000+0000+ nN.0 0..0 00.0 00.0 00.m. no. 00 00 N0. 00. 00 .00.0 00.0 m..0 00.0 .0.0 00.0w 00. mm. m0. 00. no. on. .0.+.0. 50000 .5 00.\005 .00.: 00.0 mN.0 00.0 00.0 00.0m0.000_m mm. 00. 00m 00. 00. .00.0 _¢.0 00.0 0m.0 00.0 wm.n~ omm ma. 00m 0.N 0mm .0. .0.+.0. 50000 .5 00.\005 .0m_+ .0.0 00.0 .0.0 .0.0 00..n 0N_N 00 no 00. mm 00 .00.0 0N.0 0N.0 00.0 no.0 00.n. 00 N0 00 m0 mm .0 .0.+.0. 50000 .5 00.\m05 .000. 50000 :00.x.+000 ..000 000. .+o00 .000 00. +4. 00 00. 04. .0. 000 ..m>o. co... .00.0> 00 00000.+.0m.m >00 0.0000 000000 0.0+000 .N .0.0+ .0o.+000+00 0.000+0000+ 000 >+.00000 00.00.0i000. 0000000 000 .0+o+ .000. 50000 ... 0.00h .Amo.0v0+ 000.0> 03+ +000. 000+ 00+0000 >.+000.+.00.0 0 ..00.0v00 00.0> +000. 000+ 00+0000 >.+000.+.00.0 0 .0005 00+ +0 00000 000000+0.+ .m.0 N0.0 N0.0 00.0 00.0 0.N. m... ..0. ..N. 0.N. N... .00.0 00.0 00.0 00.0 00.0 00.N N.0N ..0N ..0N 0.0N 0.0m 0.0m .0.+.0. 0.0+000 50000 .0+0+ +0 0 .0..000_0i>.50000 00.0 00.0 00.0 00.0 00.0 >... 0.0. 0.0. 0.N. 0.0. 0.0. .00.0 00.0 00.0 00.0 00.0 00.0 ¢.N. m.N_ 0.n. 0.N. m.N. ¢.N. .0.+.0. 0.0+000 50000 .0+0+ +0 0 .0..000.0i0 50000 00.0 00.0 No.0 00.0 NN.. 0.0m 0..00 0..0 N.0N 0.0m 0n.~n .00.0 00.0 00.0 0..0 00.0 00.0 00.00 0.0m 0.0m 0N..m >.0N 00.00 .0.+.0. 0.0+000 50000 .0+0+ +0 0 .0..000.0ia.50000 00.0 00.0 No.0 00.0 00.. 0.00 0..0 0..0 0.00 0.N¢ n.N¢ .00.0 00.0 00.0 00.0 >0.0 0N.N 0.0m N.om 0.0N n.0N ..on 0.00 .0.+.0. 0.0+000 50000 _0+0+ +0 0 .0.500_0 50000 00.0 0N.0 00.0 00.0 0..0 0.0 0.0 0.0 0.0 n.0 0.0 .00.0 00.0 00.0 .0.0 0..0 00.0 0.0 0.0 0.0 0.0 0.0 0.0 .0.+.0. 50000 .5 00.\0 .0.0+000 50000 .0+0+ 000_x.+000 ..000 000. .+000 .00“ 00. >0. 00 00. 00. .0. 500 ..0>0. 000. “00.0> 00 00000.+.0000 >00 0.0000 000000 0.0+000 .N .0.0+ .000>.000 0.0+000 50000 .N. 0.000 ..00.0v00 000.0> 000+o ..0 000+ 00+0000 >.+000.+.00.0 .a.0.0v0+ 00 0 ...0.0000 00 0.00.0v0. 000.0> 000+ +000. 000+ 00+0000 >_+000.+_00.0 0 ...0.000. 00 0.00.0v0. 000.0> 0000+ +000. 000+ 00+0000 >.+c00.+.00.0 0 .0.0.0v00 00 ..00.0000 000.0> 03+ +000. 000+ 00+0000 >.+000.+.00.0 0 ...0.0v00 00 “80.030. 00.0> +000. 000+ 00+0000 +.+c00.+.:0.0 0 .+005+000+ 000 00.0 030 N .0005 00+ +0 00000 000000+0 L .0.: .0.2 .0.0 00.0 U++ 00 00+ N0 04 04 u .co.+c0+00 00 .0.2 00.0 00.0 .0.. 000.000.000.0N 00.0.0.000.0N 0+.0. 0.0 00 .co_+c0+00 00 .0.2 .0.2 .0.z 00.0 _.0 ..0 ..0 ..0 ..0 _.0 me .00 >00:.00 .m.z 00.0 00.0 +0.~ N.0. 0.0. 0.0 0.00m..~ 0+.0. 0.0. ms .00 .0000 .0.: 00.0 .0.2 40.. 000.44 000.40 0.0N0.000.44 000.N0 +.0. me .0.0+c. 00 >..00 .0000.00 00 .0.2 .0.2 .0.2 40.+. 00N 00N 000 00m 000 00. N0 .0.0+c. 000+ >:00 000.x.+o00 000. .+000 .000 00. +4. 00 00. 04. .0. 000 ..0>0. 000. +00.0> 0+ 00000.+.qmww >00 0.0000 000000 0.0+000 .N .0.0+ .0+00 0000.00 .0. 0.00+ 56 .N .0.0+ .00:0_0n :00. :0 .0>0. :00. 0:0 000300 :.0+00a >00+0.u 00 +0000m .r|u|10 20.020000 puma 200.200. OOOOOOOOOOOOO OOOOOOOOOOOOO ------------- 0000000000000 0000000000000 ooooooooooooo 0000000000000 uuuuuuuuuuuuu 0000000000000 0000000000000 uuuuuuuuuuuuu IIIIIIIIIIIII ooooooooooooo nnnnnnnnnnnnn uuuuuuuuuuuuu ............. ............. ............. 0000000000000 ............. ooooooooooooo ............. ............. 0000000000000 nnnnnnnnnnnnn uuuuuuuuuuuuu 0000000000000 nnnnnnnnnnnnn 0000000000000 ------------- uuuuuuuuuuuuu uuuuuuuuuuuuu nnnnnnnnnnnnn 0000000000000 0000000000000 >¢¢hm_= 02...... I z_um 000 80.0 880 0.0 08.0 80.8 80.8 00.0 00.0 8-0.> 80 000 00. 80.0 000 800 00.0 8..8 08.8 00.0 80.. 8-08> 00.0 00. 88 00.8 08.8 00.0 08.0 08.0 .-00: .0.0 000 000 00.0 80.8 80.8 80.8 00.0 0.-08> 8.8880 00.0 800 080 80.0 0..8 00.8 0..8 0..0 8-0.» 80 200 08. 00.0 80. .8. 08.8 80.8 80.0 00.0 08.. 8.-08> 88.0 00. 08 00.8 00.8 88.0 80.. 00.. 8-001 00.0 000 080 88.0 80.8 80.8 00.8 88.0 8-08> 008 00.0 .00 000 00.0. 88.8 00.8 08.8 0..0 8-0.> 88 000 08. 00.0 .0. 08. 0..0 00.8 88.8 08.0 08.0 0-080 .0.0 088 808 88... 00.0 00.8 80.0 .0.0 ..-0.> 80.0 00. 08. 80.8 08.8 00.8 88.0 88.. 0.-08> 8.8880 08.0 880 08. 00.8 00.8 00.8 08.0 00.. 0-0.0 80 000 00 08.0 08. 88 08.8 00.0 88.0 08.0 00.. 8-002 00.0 808 800 8..0. 00.8 00.8 00.8 00.0 0-0_> 80.0 ..0 08. 80.0 00.8 08.8 8..8 88.0 0-080 088 00.0 8.0 .0. 88.8 88.8 08.8 00.0 00.. 0-0.0 88 200 80 08.0 000 08. 80.8 00.8 08.8 88.0 00.0 0-0.0 80.0 88. 08 88.8 8..8 00.0 00.0 08.0 0-001 8.8880 08.0 .8. 00 08.8 08.8 80.0 08.0 00.. 8-0.0 80 500 88 8880 0.8880 0.8.80 0; 8 +8 8 +3 8 0; 0 .+.8. .oz 0.0 +88e+8880 \8.80 .80.>< .80.>< .08 .+80.8z .. .o_L+ .o+mu oocoELO+Loa m_m .n 0.000 x_o:oaq< HemaTological daTa, Trial l. Appendix Table 4. ReTiculggyTesb Mcva gTes, l06/mm Mean Corpuscular EryThroc Hemoglobin, g/lOO ml blood HemaTocriT Z Hemoqlobin Conc. Fin. lniT. Fin. lniT. Fin. lniT. Fin. lniT. Fin. lniT. Fin. Pig No. lniT. TreaTmenT 3.6 l.7 3.0 2.9 53.0 3l.l ll0.5 5.95 7.l0 5.20 3.87 2.57 5.58 4.76 20.5 l8.5 25.3 25.7 6.82 4.72 5.l9 Yl7-6 H29-2 45 ppm Fe 36.5 25.9 27.2 26.3 28.4 7.73 Casein 0.8 .6 57.2 28.5 26.2 I8.0 3l.9 9.l0 Yl7-9 l.2 2.5 2.2 2.7 5.87 6.62 54.7 4l.l 4.89 6.75 60.7 35.6 5.56 2.54 7.60 32.l 27.2 7.25 29.7 24.0 8.67 8. Yl7-8 Y57-9 Yl7-7 H29-4 73 ppm Fe Soy 57.4 44.0 l23.2 6.57 6.99 8.l5 3l.9 28.9 28.0 28.2 6.74 8.93 36.l 25.2 27.0 26.7 3|.3 8.46 74 O— 0.. -N- ash-<- ..0 --0I ONO K\N\C> meLn va: o-on IHIOIO N-N C>r~U\ f\l\\0 mIq-wx 0.7:“. KIq-mx —O\- axe-00 NNN NOIO h~ -4-8ifi Osfxo -\O\O ... O\h-O\ g;r~a~ Ch 0.. (DIDOI N- N-- I I I h-P-P- -ln— >->->- 88 ppm Fe CaseIn OJ 0 7.08 22.8 27.l 29.2 26.l 3.72 7.94 6|.3 34.l 4.6 6.65 Y57-2 0 l 2.l 2.2 3.9 3.9 38.9 50.6 49.4 7l.3 l30.| 62.0 5.69 6.97 6.94 5.43 5.45 3.52 2.l6 3.83 32.5 29.2 22.4 29.l 3|.3 26.7 Yl7-3 Y57-3 H29-5 I37 ppm Fe Soy 49.7 3.7 l.4 55.| 27.0 28.l 28.l 7.60 2l.| 5.92 Y57-l4 O\P-O\ ON— C’fi' ‘-(V 2.8 .5 46.3 37.3 58.4 66.6 96.3 6.39 4.57 3.95 8.88 7.60 9.78 l0.|7 7.25 8.03 6.70 4.8l Yl7—4 Y57-l0 H29-l l52 ppm Fe Casein O\ g\ 34.8 24.7 28.l 2.l4 6.29 9|.l 55.3 6.l l9.5 Y57-4 O\d)d)hl C>C>C3N\ 3l.4 23. 25.4 26.8 l6 ll.50 7.90 7.8l 8.54 6.40 7.25 7.68 Yl7-5 Y57-l3 Yl7-l Y57-6 l89 ppm Fe Soy b PercenT of eryThrocyTes. lC MICVOHS. a Mean corpuscular volume, cub 75 Appendix Table 5. Serum iron, ToTal and unbound iron-binding capaciTy and Transferrin saTuraTion daTa, Trial l. Transferrin Serum Irona TIBCa UIBCa SaTuraTion Z TreaTmenT Pig No. lniT. Fin. lniT. Fin. lniT. Fin. lniT. Fin. 45 ppm Fe YI7-6 I56 I29 I92 206 36 77 8|.3 62.6 Casein H29-2 I43 II8 224 223 8| l05 63.8 52.9 Yl7-9 l4l IIO I79 209 38 99 78.8 52.6 73 ppm Fe Yl7-8 I50 ll8 235 I46 85 28 63.8 80.8 Soy Y57-9 l23 l25 229 l9l I06 66 35.6 28.9 Yl7-7 l2l I69 203 248 82 78 53.7 65.4 H29~4 I36 97 230 |84 94 87 59.| 52.7 88 ppm Fe YI7-2 I38 |50 I76 227 38 77 78.4 66.I Casein Y57-I2 239 l00 36l l3l l22 3| 66.2 76.3 Yl7-ll I37 207 200 299 63 92 68.5 69.2 Y57-2 246 I62 345 2l8 99 57 7|.3 74.3 I37 ppm Fe YI7-3 l29 l59 224 262 95 IO3 57.6 60.7 Soy Y57-3 I46 I68 I96 264 50 96 74.5 63.6 H29-5 I54 I2l 209 I80 55 59 73.7 67.2 Y57-l4 I88 I72 208 205 20 33 90.4 83.9 l52 ppm Fe Yl7-4 97 206 I89 290 92 84 5|.3 7|.0 Casein Y57-I0 I59 I73 279 248 |20 75 57.0 69.8 H29-l I73 I97 225 26| 52 64 76.9 75.5 Y57-4 I46 204 294 245 I48 4| 49.7 83.3 I89 ppm Fe YI7-5 |I0 I79 227 237 Il7 58 48.5 75.5 Soy Y57-l3 l55 I55 462 227 307 72 33.5 68.3 Yl7-l I42 .224 I67 273 25 49 85.0 82.I Y57-6 2ll l57 3Il 2l2 I00 55 67.8 74.l a mcg/IOO ml serum. Serum proTein analyses, Trial Appendix Table 6. Serum y-qlobulinb lniT. Serum .B-globulinb lniT. Serum a:globulinb lniT. Serum Albuminb lniT. ToTal Serum ProTeina Fin. Fin. In. Fin. lniT FIn. Pig No. TreaTmenT 6.4 l9.5 3|.I |4.5 l5.6 ll.6 6.2 6.3 33.I 29.4 3l.8 29.4 l4.2 YI7-6 H29-2 45 ppm Fe I3.0 3|.I 52.6 26.3 22.9 7.9 7.2 6.6 Casein I8.7 II. I5.2 45.| 32.9 28.8 34.2 6.5 YI7-9 7.5 I0.4 8.8 l9.6 2l.0 I3.6 l3.5 l4.0 I2.9 I2.0 34.| 26.l 33.9 33.6 Yl7-8 Y57-9 73 ppm Fe Soy 5.I l6.0 7.6 l3.8 25.8 6.2 33.5 6|.6 6.7 7.3 7.2 YI7-7 H29-4 25.2 24.6 3l.9 8.4 38.3 23.9 l5.6 30.3 28.2 8.5 6.6 6.| YI7-2 88 ppm Fe 33.0 I3.6 24.5 7.7 Y57-I2 Casein l9.6 l9.3 l3.0 I4.3 35.6 47.7 30.6 28.5 l4.2 5.5 5.7 Yl7-II Y57-2 40.3 48.5 25.6 29.I I4.7 6.2 5.6 9.2 I5.5 6.0 8.9 39.2 60.3 3I.2 23.9 l3.2 l0.I l9.6 20.3 Yl7-3 I37 ppm Fe 5.9 42.0 5|.2 25.8 26.5 II.7 l3.0 5.I II.| 7.2 Y57-3 Soy 29.2 l3.2 42.0 25.| 29.3 34.5 7.3 6.4 H29-5 35.I 46.4 3l.4 29.6 I3.4 l2.0 20.I l2.0 4.9 Y57-l4 mNI‘O 2|. l8.9 23.7 34.0 20.4 I2.3 2. |2.0 I4.3 l4.6 I|.5 I|.8 20.4 32.3 33.I 32.0 3|.I 30.5 26.9 25.5 28.4 42.7 45. 32.0 4|.7 36.0 37.8 28.8 38.| 6.3 6.l 7.5 7.l Yl7-4 Y57-l0 H29-l Y57-4 I52 ppm Fe Casein Nfl'fl'o NON I0. l8.5 I7.9 l8.5 l7.4 I.6 ll.4 I2.0 ll.6 I5.2 3.5 I3.9 3. 28.2 37.8 28.4 37.8 3|.7 34.3 29.8 34.2 50.0 38.3 49.2 38.6 37.7 35.2 35.2 3l.0 7.2 5.9 6.4 5.9 6. 6. 5.9 6. YI7-5 Y57-3 YI7-l Y57-6 l89 ppm Fe Soy b PercenT of ToTal serum proTein. a g/IOO ml serum. 77 Appendix Table 7. Balance daTa, Trial l.a Food Fe Fecal Urinary Fe Fe inTake, inTake, Fe, Fe, reTenTion, reTenTion, TreaTmenT Pig No. Q, mg. mg mg. mg, g_g 45 ppm Fe YI7-6 l50 6.75 4.l7 0.38 2.20 32.59 Caseinb 73 ppm Fe Yl7-8 223 l6.30 l5.55 0.56 0.19 |.l7 Soy Y57-9 233 l7.06 l0.2I 0.23 6.62 38.80 88 ppm Fe YI7-2 250 22.00 7.80 0.I| l4.09 64.05 Casein Y57-l2 208 l8.27 9.9l 0.l7 8.l9 44.83 I37 ppm Fe YI7-3 250 34.25 l3.57 0.52 20.I6 58.86 Soy Y57-3 250 34.25 7.62 0.25 26.38 77.02 l52 ppm Fe Yl784 250 38.00 8.43 0.|3 29.44 77.47 Casein Y57-l0 250 38.00 I6.76 0.08 2I.l6 55.68 I89 ppm Fe YI7-5 240 45.36 I9.l5 0.45 25.76 56.79 Soy Y57-l3 250 47.25 2l.47 0.26 25.52 54.0I a Per day. Balance daTa of H29-2 noT used in sTaTisTical analysis because of negaTive iron balance. Feed Weighf, Kg, Av.Da. Av.Da. Gain/ 4 wT 5 wT 6 wT Gain,g Feed,g 3 wT 2 wT Pig performance daTa, Trial 2. lniT. Pig No. Appendix Table 8. TreaTmenT YI7-2 Y52-5 Y6-l IOI ppm Fe Casein 225 0.7l 238 290 325 I59 I38 209 202 CDCDOO 3861? NO\ “WOT-0&0 CONGO mom-n ON? 8000 .0.0 V N? O\O€DN mxoauo .... NI8--r\ #0 O 8000 O... NN'l-m 877? NON \O—InLn >->->->- a) u. E Q>~ 0.0 V) In 0\ 0.58 0.72 0.62 78 68 54 .58 0.6l 20| 224 2I6 295 I36 I2l I25 I8I Y6-5 YI7-6 Y6-9 Y52-l I48 ppm Fe Casein 0.80 0.6 0.6 0.69 0.74 0.73 0.86 0.75 242 282 282 367 253 263 3I0 257 266 I93 I77 I87 252 I86 I9I 266 I93 203 9.40 8.50 8.82 I2.l6 8.84 9.98 II.80 9.I2 9.94 9.96 I3.68 7.82 6.24 6.44 6.48 8.96 9.58 6.46 6.92 7.20 I0.60 6.30 4.94 4.92 4.60 6.58 5.42 5.86 7.36 5.56 4.20 4.86 3.74 5.54 3.96 4.60 3.|4 3.06 2.66 3.78 2.62 3.06 4.02 2.86 2.66 2.32 2.28 3.34 2.82 2.88 Y6-2 Y52-2 Y6-8 YI7-5 Y6-7 Y52-3 Y6-3 YI7-4 YI7-3 Y52-4 Y6-6 I47 ppm Fe Soy I89 ppm Fe Casein l89 ppm Fe 292 406 239 259 3I4 I57 6.|2 4.50 2.70 2.34 Y52-7 Soy 79 .mm+>ooLc+>Lm 0o +cmoLom 0 .mcoLo_e o_0:o .ms:_o> Lm_:omzacoo :00: 0 8.. 0.8 ..88 0.08 08.8 08.8 0.00 ..00 8.00 0.0. 00.0 00.8 0-080 8.. 0.. 0.08 0.08 88.8 80.8 8.00 0.00 0.88 8.00 08.0. 00.0 8-80 0.0 _.8 0.08 0.88 00.0 08.8 0.00 8.00 8.88 0..0 80.0 00.8 8-080 068 8.0 8.. ..88 8.08 0..0 00.8 8.08 0.00 ..08 0..8 .8... 00.0 8-0.0 88 000 00. 8.8 _.0 0.08 0.08 80.8 88.8 8.00 8..8 0.80 0.00 80.8 00.8 8-0.0 0.0 0.. 0.08 0.88 80.8 08.8 0.00 0.08 0.00 0.80 80.0 0..0 8-80 0.8 0.8 0.08 0.88 00.8 .8.8 0.80 0.00 ..80 0.00 00.8 80.8 8-080 8.8880 8.0 0.. 8.08 8.88 00.8 08.8 0.08 8..8 0.80 0.08 08.0 08.0 0-80 80 200 00. 0.. 8.8 8..8 8.88 08.0 00.8 0.80 0.00 0.80 0.80 80.8 80.8 8-0.> 8.0 8.. 8.08 8.88 08.8 00.8 8.80 8.08 0..0 0.80 88.8 00.0 0-80 8.. ... 0.08 8..8 08.8 00.8 0.00 ..00 0.00 0.80 8..0 08.0 0-08> 060 0.0 ..8 8.08 0.08 88.8 88.8 0.80 8.08 8.00 0.80 00.8 0..0 0-8> 80 200 08. 8.. 0.8 0.08 8.88 80.8 .0.8 0.00 8.00 8.0. 8.00 .8.8 80.8 .-080 8.0 8.0 0.08 0.08 .0.8 88.8 0.00 0.00 0.00 8.80 00.8 80.0 0-80 0.0 0.0 8.08 8.08 88.8 00.8 0.80 8.08 8..0 0.00 8..8 80.0 8-0.> 8.8880 0.0 8.. 0.08 0.88 08.8 00.8 ..80 ..00 8.00 0.00 08.8 00.0 8-80 80 200 08. 8.8 0.8 8.88 8.08 00.8 00.8 0.80 8.00 0.00 0.00 80.8 00.8 8-08> 0.8 0.. 8.08 8.08 8..8 80.8 ..00 8.08 ..08 0.88 00.0 88.0. .-080 0.8 8.. 0.88 8.88 88.8 00.8 8.00 ..00 0.0. 8..0 88.8 00.8 .-0.0 068 0.8 0.. 0.88 ..80 00.8 00.8 8.80 8.00 0.00 0.08 80.8 .0.0 8-8> 80 208 80 8.8 0.0 8.08 8.08 80.8 .0.8 0..0 0.00 8.0. 0.80 0..8 00.8 .-80 0.8 8.. 0..8 8.08 .8.8 00.8 0.00 8.00 8.0. 8.80 0..8 00.0 8-080 8.8880 0.. 0.. 0.08 8.08 08.8 00.8 0.80 ..00 0.00 0.80 08.0 00.0 0-0.> 80 000 .0. .8.8 .0.8. .8.0 .0.8. .8.8 .0.8. .8.8 .+.8_ .8.8 .+.8. .8.8 .+_8. .oz 0.0 +c8e+8880 omm+>oo_:o_+mm m>oz mEE\©o_ .ocoo c_oo~woeoI .wlF_Loo+oEmI 600.0 _E oo_\m .mm+ ooLc+>Lw Ln.:omaacoo cow: .c_no_mOEoI .N _o_L+ .o+mo _oo_mo.o+oeox .0 8.880 x.88800< 80 Appendix Table I0. Serum iron, ToTaI and unbound iron-binding capaciTy and Transferrin saTuraTion daTa, Trial 2. Transferrin Serum Irona TIBCa UIBCa SaTuraTiongZ TreaTmenT Pig No. lniT. Fin. lniT. Fin. lniT. Fin. lniT. Fin. IOI ppm Fe YI7-2 42 95 238 I52 I96 57 l7.6 62.5 Casein Y52-5 78 l0l I2l I79 43 78 64.5 56.4 Y6-I 63 87 2l4 I9I |5I l04 29.4 45.5 95 ppm Fe Y6-4 75 85 I47 2I6 72 I3I 5I.0 39.4 Soy YI7-I 4| 89 256 I73 2I5 84 l6.0 5|.4 Y50-I 50 |I3 l25 I98 75 85 40.0 57.I Y52-6 56 I02 274 I90 2I8 88 20.4 53.7 I48 ppm Fe Y6-5 l29 86 223 244 94 l58 57.8 35.2 Casein YI7-6 52 84 238 I68 l86 84 2I.8 50.0 Y6-9 79 97 247 208 I68 III 32.0 46.6 Y52-I 39 90 244 I73 205 83 I6.0 52.0 I47 ppm Fe Y6-2 85 53 l85 I2I IOO 68 45.9 43.8 Soy Y52-2 44 l4l 229 I99 I85 58 l9.2 70.9 Y6-8 95 I06 2I4 246 Il9 I40 44.4 43.I YI7-5 23 9| I52 I34 I29 I43 I5.l 67.9 l89 ppm Fe Y6-7 22 375 I38 475 ll6 I00 l5.9 78.9 Casein Y52-3 65 89 24I I84 I76 95 27.0 48.4 Y6-3 59 I77 226 302 I67 I25 26.l 58.6 YI7—4 33 94 238 I83 205 89 I3.9 5|.4 l89 ppm Fe YI7-3 I30 292 I9I 353 6| 6| 68.I 82.7 Soy Y52-4 44 233 262 3I0 2l8 77 l6.8 75.2 Y6-6 67 I53 206 296 I39 I43 32.5 5|.7 Y52-7 77 l7l 247 3l6 I70 I45 3I.2 54. a mcg/IOO ml serum. Fin. I2.I ll. I0.7 ll.4 Serum Y-globulinb lniT. 24.0 28.2 25.8 26.6 20.7 Fin. ll.4 I4.7 l6.7 l4.2 I3.6 I2.4 5. Serum gfi-qlobulinb lniT. lI.5 l3.8 l3.0 I4.8 I2.0 32.0 30.8 30.9 33.3 34.I Serum or-globulinb 28.5 3|.7 32.0 29.2 26.l 42.4 4I.7 42.8 44.I 4I.8 Serum Albuminb 35.6 28.5 28.3 3|.2 38.4 Serum ProTeina niT. Fin. 6.2 6.6 7.I 6.8 6.6 6.5 6.I 6.7 6.7 6.7 ToTaI Serum proTein analyses, Trial 2. Pig No. Yl7-2 Y52-5 Y6-I Y6-4 Yl7-I Y50-I Casein Appendix Table II. Soy IOI ppm Fe 95 ppm Fe TreaTmenT 50 0m 00 O m ll.6 I2.6 30.0 3l.8 27.7 26.5 2l.9 4|.0 26.5 39.5 6.5 6.5 8.0 6.5 Y52-6 l0.4 5.9 l3.5 I3.9 I3.0 II.9 I3.3 II.9 I3.9 32.8 25.0 28.4 24.8 27.6 33.0 30.4 29.7 30.0 26.5 28.4 25.9 30.0 29.0 28.0 l5.8 I2.I I3.4 l3.8 I4.8 II.8 |5.0 I2.5 I2.4 l2.8 l2.8 I3.4 I0.0 II.2 I3.I I2.6 II.3 I2.0 l3.8 I4.3 II.2 II.3 I2.2 l3.7 ll.6 I4.7 ll.6 I0.9 I2.4 I2.9 l3.2 l2.8 .0 29.7 3|.7 32.2 29.3 30.2 33.6 30.4 24.8 30.7 27.4 29.9 28.3 25.5 28.5 32.7 28.9 29.0 3|.6 29.2 27.6 2 . 25.5 28. 33. 29.4 33.3 3|.6 29.I 3l.4 40.6 43.9 43.| 46.8 50.9 42.7 48.7 45.3 48.9 38.7 28.0 ’ 32.I 30.5 37.0 27.8 25.3 29.4 26.7 29.0 27.0 6.4 6.6 5.9 5.9 6.2 6.6 6.7 7.9 6.5 7.I 6.4 5.7 7.I 6.I b PercenT of ToTal serum proTein. Y6-5 YI7-6 Y6-9 Y52-I Y6-2 Y52-2 Y6-8 Yl7-5 Y6-7 Y52-3 Y6-3 YI7-4 YI7-3 Y52-4 Y6-6 Y52-7 Casein Soy Casein Soy I48 ppm Fe I47 ppm Fe l89 ppm Fe I89 ppm Fe a g/IOO ml serum. Appendix Table l2. 82 Balance daTa, Trial 2.6 Food Fe Fecal Urinary Fe Fe inTake, inTake, Fe, Fe, reTenTion, reTenTion, TreaTmenT Pig No. 9 mg mg mg . mg 1 IOI ppm Fe Yl7-2 237 23.90 l3.75 0.09 l0.06 42.09 Casein Y52-5 I55 l5.62 6.29 0.I2 9.2I 58.96 95 ppm Fe Y6-4 207 l9.63 5.72 .I3 l3.78 70.20 Soy Yl7-I 232 22.04 5.30 .l2 l6.62 75.4I I48 ppm Fe Y6-5 228 33.74 20.48 0.I7 I3.09 38.80 Casein YI7-6 2II 3|.l8 l2.86 0.08 l8.24 58.50 I47 ppm Fe Y6-2 235 34.55 II.5I 0.I8 22.86 66.I7 l89 ppm Fe Y6-7 236 44.67 23.27 . 2l.27 47.62 Casein Y52-3 236 44.60 I9.l0 . 25.34 56.82 I89 ppm Fe Yl7-3 234 44.I6 l0.25 0.I 33.77 76.47 Soy Y52-4 235 44.42 I0.l5 0.I 34.I7 76.92 a Per day. MIC R lllllllllllllllllallIIIIIIIISIILIIIIIIIIIIEs