title: Isoleucine requirement of broiler chicks as affected by the concentrations of leucine and valine in practical diets.
abstract: 1. Chicks were fed on an isoleucine-deficient diet, with 6 added concentrations of isoleucine to determine their isoleucine requirement and an additional 6 treatments were devised to determine their isoleucine requirement when dietary leucine and valine contents were increased. 2. The diet deficient in isoleucine contained 5.6 g/kg isoleucine with leucine and valine contents of 20.1 and 10.3 g/kg, respectively. Supplementation with leucine and valine increased these to 24.7 and 12.6 g/kg, respectively. 3. The isoleucine requirement was not affected by dietary leucine and valine contents in a diet with 13.4 MJ of ME per kg. Analysis of variance and Least Significant Difference of means indicated an isoleucine requirement of 7.2 g/kg. Non-linear regression of the same data indicated an isoleucine requirement of 8.44 g/kg, based on weight gain, or 8.19 g/kg based on food efficiency. 4. Reasons for the failure to find an imbalancing effect of branched chain amino acids in practical diets are discussed.
authors.affiliation: Department of Poultry Science, Ohio State University, Columbus 43210.
authors.forename: G
authors.initials: G
authors.lastname: Barbour
authors.forename: J D
authors.initials: JD
authors.lastname: Latshaw
mesh_terms: D000704:Analysis of Variance; D000821:Animal Feed / Q000592:standards*; D000818:Animals; D002645:Chickens / Q000254:growth & development*; D004435:Eating; D007532:Isoleucine / Q000008:administration & dosage*; D007930:Leucine / Q000008:administration & dosage*; D011897:Random Allocation; D012044:Regression Analysis; D014633:Valine / Q000008:administration & dosage*; D015430:Weight Gain
chemical_list: D007532:Isoleucine; D007930:Leucine; D014633:Valine