Assessment of protein quality in heat-treated soybean products using the growth responses of lambs and calves and a nylon bag-rooster assay.
Three studies were conducted to evaluate N and amino acid (AA) availability from processed soybean (SB) products. In Exp. 1 and 2, treatments consisted of corn-cottonseed hull basal diets plus SB products including SB meal (SBM); ground, raw SB (RSB); or extruded SB (ESB). In Exp. 1, 15 Suffolk (28.6 kg) and 15 Louisiana native breed (16.3 kg) ewe lambs were used in a 35-d growth trial. Although breed affected (P < .10) DMI and ADG of lambs, the diets did not (P > .10). In Exp. 2, 12 Suffolk wether lambs (34.0 kg) were used in a 3 x 3 multiple-square Latin square design N metabolism trial. Lambs fed RSB tended (P = .13) to retain more N than those fed ESB, but N retained by lambs fed RSB and ESB was similar (P > .10) to that of lambs fed SBM. In Exp. 3, four crossbred steer calves (240 kg) were used in a 4 x 4 Latin square design N metabolism trial with the above treatments plus heat-damaged SB (HDSB). Calves fed RSB and ESB retained similar (P > .10) amounts of N. Compared with calves fed RSB and ESB, calves fed SBM retained more (P < .10) N. Calves fed HDSB retained less (P < .10) N than those fed other diets. The individual SB products and the total mixed diets used in Exp. 3 were incubated intraruminally in nylon bags and the residual DM recovered and precision-fed to cecectomized roosters to estimate its intestinal AA digestibility. Digestibility of residual AA seemed to be relatively uniform across AA.(ABSTRACT TRUNCATED AT 250 WORDS)
Griffin
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Department of Dairy Science, Louisiana State University Agricultural Center, Baton Rouge 70803.
Bunting
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Sticker
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Vora
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B
D000596:Amino Acids / Q000032:analysis / Q000378:metabolism; D000821:Animal Feed / Q000592:standards*; D000818:Animals; D001806:Blood Urea Nitrogen; D001947:Breeding; D002417:Cattle / Q000254:growth & development* / Q000378:metabolism; D002432:Cecum / Q000601:surgery; D002645:Chickens / Q000378:metabolism / Q000601:surgery; D004044:Dietary Proteins / Q000378:metabolism / Q000592:standards*; D004435:Eating; D005260:Female; D005511:Food Handling; D006358:Hot Temperature; D007422:Intestines / Q000737:chemistry / Q000502:physiology; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D009753:Nutritive Value; D011897:Random Allocation; D012417:Rumen / Q000737:chemistry / Q000502:physiology; D012756:Sheep / Q000254:growth & development* / Q000378:metabolism; D013025:Glycine max; D015430:Weight Gain
D000596:Amino Acids; D004044:Dietary Proteins; D009584:Nitrogen