A simplified diet for assaying methionine activity.
Several experiments were undertaken to evaluate diets that could be used to bioassay methionine activity in various compounds. The following semipurified diets were tested: a corn-soy-gelatin basal (CSG) diet supplemented with essential amino acids (EAA) at 23% crude protein (CP); a soybean meal diet at 23% CP; and a soybean meal diet at 15% CP with all the protein coming from dehulled soybean meal and starch, glucose, and fat used as sources of energy. The CSG and 15% CP soybean meal diets proved to be sensitive in their response to methionine supplementation. Birds fed the CSG diet supplemented with methionine and tryptophan were smaller (P less than .01) than birds fed the 23% CP soybean meal diet, thus suggesting that something other than EAA was limiting the performance of birds fed this diet. Based on sensitivity to methionine supplementation, simplicity and cost of diet, the low protein soybean meal diet seems most appropriate for methionine bioassays.
Summers
J D
JD
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
Blackman
S
S
Leeson
S
S
D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001681:Biological Assay; D001835:Body Weight; D002645:Chickens / Q000254:growth & development*; D008297:Male; D008715:Methionine / Q000378:metabolism*
D008715:Methionine