title: Tryptophan requirement of pigs in the weight category 10 to 20 kilograms.
abstract: Experiments were conducted to determine the tryptophan (Trp) requirement of 10- to 20-kg pigs. A Trp-deficient experimental diet (.11% total Trp, 18% CP, 3,320 kcal of ME/kg) was composed of corn, feather meal, corn gluten meal, soybean meal, and dried whey. True digestibility of Trp in the experimental diet was 70% (.077% digestible Trp) as established in a digestibility assay that involved cecectomized, adult cockerels (Exp. 1). An initial pig study (Exp. 2) verified that the experimental basal diet, when fortified with sufficient L-Trp, was capable of producing growth rate and feed efficiency similar to that of pigs fed a conventional corn-soybean meal-dried whey diet (18% CP, 3,320 kcal of ME/kg). In Exp. 3, crossbred pigs with an average BW of 10.9 kg were fed the Trp-deficient basal diet supplemented with 0, .015, .030, .045, .060, and .075% L-Trp. In Exp. 4, crossbred pigs that averaged 9.5 kg were fed the basal diet fortified with .030, .045, .060, and .075% L-Trp. By examining the data from Exp. 3 and 4 together, the digestible Trp requirement for maximum daily weight gain was estimated to be .14% of the diet. Assuming an 88% true digestibility of Trp in commercial diets based on corn and soybean meal (calculated from published data), the total Trp required in practice would be .16% (.89% of the dietary protein).
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801.
authors.forename: Y
authors.initials: Y
authors.lastname: Han
authors.forename: T K
authors.initials: TK
authors.lastname: Chung
authors.forename: D H
authors.initials: DH
authors.lastname: Baker
mesh_terms: D000821:Animal Feed / Q000592:standards*; D000818:Animals; D001682:Biological Availability; D002645:Chickens / Q000502:physiology; D004063:Digestion; D008297:Male; D011897:Random Allocation; D012044:Regression Analysis; D013552:Swine / Q000254:growth & development* / Q000502:physiology; D014364:Tryptophan / Q000008:administration & dosage* / Q000378:metabolism / Q000493:pharmacokinetics; D015430:Weight Gain
chemical_list: D014364:Tryptophan