EFFECTS OF ADDED FAT, DEGRADABLE INTAKE PROTEIN, AND RUMINALLY-PROTECTED CHOLINE IN DIETS OF FINISHING STEERS

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1 Cttlemen s Dy 1998 EFFECTS OF ADDED FAT, DEGRADABLE INTAKE PROTEIN, AND RUMINALLY-PROTECTED CHOLINE IN DIETS OF FINISHING STEERS J. S. Drouillrd, A. S. Flke, nd G. L. Kul Summry siniicntly improved rowt perormnce nd crcss trits. A totl o 16 yerlin steers ws used in two inisin experiments to evlute interc- (Key Words: Finisin Cttle, Coline, Ft, tions etween levels o dietry t, protein nd Protein, Crcss.) ruminlly protected coline. In Tril 1, steers received diets tt comined levels o 0% or Introduction 5% dded t (coice wite rese), 10.8% or 1.5% crude protein, nd 0 or 5 rms per Protein requirements o rumen microored dily o ruminlly protected coline. nisms re inluenced y te mount o Steers were ed in pens o ive ed ec or 89 ville enery; s ville croydrte dys. Addin t decresed intke (P<.01), increses, more ruminlly derded protein vere dily in (P<.1), nd crcss weit is needed to stisy requirements o te (P<.07) nd incresed crcss yield rde ruminl microlor. Strc is extensively (P<.06) ut did not lter eed eiciency (P>.9). derded to voltile tty cids y rumen Incresin te protein level rom 10.8 to 1.5% microlor. Conversely, miniml lipid did no siniicnt eects on live niml peror- estion tkes plce in te rumen. Teremnce, ut te i protein level resulted in ore, te potentil exists or n interction reter (P<.05) percente o crcsses rdin etween source o enery (i.e., lipid vs USDA Coice. Coline supplementtion strc) nd ruminl protein requirements. tended to increse vere dily in (P=.13) s Prtil replcement o eed rins wit well s te percente o crcsses rdin niml ts my mke it esile to reduce USDA Coice (P=.3). Coline lso incresed te mount o protein tt must e suppledressin percente (P<.07); tis eect ws mented to eedlot cttle nd tus, reduce most pronounced wen t ws not included in supplementtion costs. te diet, indictin n interction etween t nd coline (P<.1). In Tril, steers were ed Coline normlly is provided in de common inisin diet, wic ws top- qute quntities s result o syntesis y dressed wit ruminlly protected coline t to ruminl protozo. Tereore diets tt 9 rms per ed dily or no dded coline. crete ruminl conditions tt compromise Coline supplementtion yielded liner im- protozol rowt my reduce coline supprovements in rte o in (P<.01), dry mtter ply postruminlly. Hi-concentrte diets intke (P<.05), nd crcss weit (P<.01). All requently produce ruminl ph to te rne mesures o crcss tness incresed s te o 5.5 to 5.8, wic is less tn optiml or mount o coline incresed. Addin ruminlly proliertion o protozo. Includin t in protected coline to diets o inisin steers te diet my urter reduce protozol popu- ltions. Consequently, diets tt induce 71

2 low protozol popultions my eneit rom ciency were determined y clcultin inl coline supplementtion. In ddition, previous live weit s ot crcss weit divided y reserc s suested tt coline cloride is common dressin percente. derded extensively in te rumen. Supplementin coline s ruminlly protected orm Tril. A dose-titrtion experiment my provide te coline needed to stisy ws conducted to determine te optimum requirements or optiml rowt rte in inis- inclusion level or ruminlly protected in cttle. coline. Cttle were dpted to i rin diets, processed, nd llocted to tretws Te ojectives o tese studies were to ments in mnner identicl to tt used or evlute eects o vrious levels o dded t, Tril 1. Tretments were composed o derdle intke protein, nd ruminlly pro- incresin levels o ruminlly-protected tected coline nd to determine ow tese coline. Te i-t, i protein diet ctors interct wit respect to teir inluence rom Tril 1 ws top-dressed wit, 3, 4, on perormnce nd crcss trits o inisin 6, 7, 8, or 9 rms per ed dily o coline ee steers. A secondry ojective ws to s t-encpsulted product. Cttle in determine te optimum level o ruminlly our pens were ed te control diet (no protected coline or inisin ee steers. dded coline), nd sinle pen o cttle llotted to ec level o dded coline. Experimentl Procedures Tril 1. A tril ws conducted usin 159 Results nd Discussion crossred ee steers to evlute inisin perormnce o cttle ed diets cominin Tle summrizes te eects o vrious levels o protein (10.8 or 1.5%), coice wite rese nd dietry protein on coice wite rese (0 or 5%), or ruminlly perormnce nd crcss crcteristics o protected coline (0 or 5 /ed dily; Bl- steers (Tril 1). No siniicnt interctions cem Corportion). Cttle were ed common occurred etween dietry protein nd t. diet or severl weeks to minimize vrition in Incresin dietry protein did not inluence ut ill. Followin te trnsition period, cttle in or eed eiciency, ut te percente were treted or internl nd externl prsites o crcsses rdin USDA Coice ws nd implnted wit Synovex Plus. Steers drmticlly improved (P<.05) or cttle ed were strtiied y weit nd ssined rn- te ier protein level. Addin coice domly, witin strt, to ec o te eit tret- wite rese to te diet depressed eed ment roups. Tretments were rrned s intke (P<.01) nd vere dily in 3 ctoril, in our replictes. Cttle were (P<.1), ut eiciency ws not ltered. oused in prtilly covered, 14 x 8 pens wit concrete surces nd ed once per dy. Te Interctions etween coline nd t re concentrte in te diets ws incresed sown in Tle 3. Dietry levels o t or incrementlly rom 40 to 9% y eedin ec coline did not inluence inl live weit o ive step-up diets or period o to 6 dys. ut did ect dressin percente. Addin Experimentl diets were ed or 89 dys. 5 /dy o coline siniicntly incresed dressin percente (60.1 vs 60.9%). Te Steers were slutered wen tey eect o coline on dressin percente cieved n estimted outside t tickness ws more pronounced wen t ws not (1t ri) o 0.4 inces. Dily in nd ei- included in te diet (P<.1). Feedin coice 7

3 wite rese depressed rte o in (P<.1), ut te ddition o coline tended to llevite tis eect (P=.15). Dry mtter intke ws reduced wit te ddition o coline wen t ws not included, ut intke ws not impcted retly y coline wen coice wite rese ws dded. Addin coline to te diet tended to improve eed eiciency wen t ws not dded to te diet (P=.13). Yield rde lso ws impcted y te interction etween coline nd t (P<.1). Oter mesures o crcss tness ollowed similr trends ut were not siniicnt. Results o Tril re summrized in Tle 4. Ec rm o dded coline resulted in n increse in eed intke o 0.33 l/ed dily nd concomitnt increse in in o.09l/ed dily. Crcss weits were incresed y nerly 5 l/rm o dded coline. All mesures o ody tness tend to support te suestion tt incresin te level o ruminlly protected coline in te diet my reduce dys required to cieve desired compositionl endpoint. Tle 1. Compositions (Dry Bsis) o Experimentl Diets 10.8% Protein 1.5% Protein Item 0% Ft 5% Ft 0% Ft 5% Ft Rolled corn, % Ground ll y, % Coice wite rese, % Cr-Mil Glo, % Deulled soyen mel, % Corn luten mel, % Ure, % Limestone, % Potssium cloride, % Slt, % Mnesium oxide, % Ammonium sulte, % Vitmin/minerl premixes, % Ruminlly-protected coline, /ed/dy 0 or 5 0 or 5 0 or 5 0 or 5 Crude protein, % NPN, % Crude Ft, % NEm, Mcl/l NE, Mcl/l Clcium, % Posporus, % Potssium, % Mnesium, % Sulur, % Rumensin, /ton Tyln, /ton Diets contined te ollowin concentrtions o dded vitmins nd trce minerls (dry sis): 1,00 IU/l vitmin A; 10 IU/l vitmin E;.05 ppm colt; 10 ppm copper;.6 ppm iodine; 60 ppm mnnese;.5 ppm selenium; 60 ppm zinc. 73

4 Tle. Eects o Added Ft nd Protein Level on Perormnce nd Crcss Trits (Tril 1) 0% Added Ft 5% Added Ft Item 10.8% CP 1.5% CP 10.8% CP 1.5% CP SEM Numer o ed Initil weit, l Finl live weit, l c Gin, l/dy Dry mtter intke, l/dy de. d e Feed:Gin Liver scesses, % Hot Crcss Weit, l Dressin percente Kidney, pelvic nd ert t t ri t tickness, in Rieye re, in USDA Yield Grde USDA Coice, % Eect o dded t (P<.1). Eect o dded t (P<.01). c 0% t reter tn 5% t (P<.1). de Mens in te sme row wit common superscripts re not dierent t P<.1. Eect o protein (P<.05). Tle 3. AEects o Added Ft nd Protected Coline on Perormnce nd Crcss Trits (Tril 1) 0% Added Ft % Added Ft Item Coline> 0 /dy 5 /dy 0 /dy 5 /dy SEM Numer o ed Initil weit, l Finl live weit, l Gin, l/dy de Dry mtter intke, l/dy i 0.6 i Feed:Gin Liver scesses, % Hot crcss weit, l c Dressin percente e 1t ri t tickness, in Kidney, pelvic nd ert t Rieye re, in c USDA Yield Grde USDA Coice, % Eect o dded t (P<.1). Eect o dded coline (P<.1) c Ft y coline interction (P<.1). d Eect o dded t (P<.01). e Ft y coline interction (P<.05). Eect o dded coline (P=.1) i Mens in te sme row wit common superscripts re not dierent t P<.1. 74

5 Tle 4. Eects o Ruminlly Protected Coline on Finisin Perormnce nd Crcss Crcteristics o Steers (Tril ) Item Intercept ± SE Slope ± SE Siniicnce (P) Numer o ed 60 Initil weit, l 88 ± 10.3 ±.1.89 Finl live weit, l 1173 ± ±.6.03 Gin, l/dy 3.30 ± ± Dry Mtter Intke, l/dy 0.0 ± ± Gin:Feed.163 ± ± Liver scesses, %.17 ± ±.70.0 Hot Crcss Weit, l 710. ± ± Dressin percente 60.5 ±.5.07 ±.05. 1t ri t tickness, in.39 ±.03.0 ± Kidney, pelvic nd ert t.1 ± ±.0.0 Rieye re, in 13.5 ± ± USDA Yield Grde 1.76 ± ±.0.0 USDA Coice, % 49.1 ± ± Intercept represents te expected vlue wen steers re ed no supplementl coline. Te slope represents te expected cne or ec 1 increse in te mount o supplementl coline ed. 75