Limiting amino acids for a corn and soybean meal diet in weaned calves less than three months of age.
Holstein bull calves (n = 51) weaned at 6 wk of age were used in four N balance trials for 4 wk (Trials 1 to 3) or for 2 wk (Trial 4) from 8 wk of age to identify limiting amino acids for a corn and soybean meal diet. The calves were trained to maintain reflex closure of the reticular groove throughout the trials. In Trial 1, administration of .111 g of DL-methionine plus .333 g of L-lysine monohydrochloride/kg BW through the reticular groove increased N retention compared with the control that received isonitrogenous L-glutamine, but administration of .333 g L-lysine monohydrochloride/kg BW alone did not increase N retention in Trial 2. In Trial 3, administration of .111 g of DL-methionine/kg BW improved N balance compared with the control, although the improvement was not detected when DL-methionine was restricted to .022 g/kg BW. In Trial 4, administration of the mixture of .111 g of DL-methionine, .333 g of L-lysine monohydrochloride, and .055 g of L-tryptophan/kg BW increased N retention in calves compared with calves that received an isonitrogenous mixture of .111 g of DL-methionine and .274 g of L-glutamine/kg BW, or .111 g of DL-methionine, .055 g of L-tryptophan, and .234 g of L-glutamine/kg BW. The present results suggest that methionine was the first-limiting and that lysine was probably the second-limiting amino acid for the corn and soybean meal diet in weaned calves less than 11 wk of age, although tryptophan may be either co-limiting with lysine or third-limiting.
Abe
M
M
School of Veterinary Medicine, Azabu University, Sagamihara, Japan.
Iriki
T
T
Funaba
M
M
Onda
S
S
D000596:Amino Acids / Q000008:administration & dosage / Q000378:metabolism*; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight; D002417:Cattle; D004063:Digestion / Q000502:physiology*; D005243:Feces; D005527:Food, Fortified; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza; D013025:Glycine max; D013997:Time Factors; D014886:Weaning; D003313:Zea mays
D000596:Amino Acids; D009584:Nitrogen