Holstein bull calves weaned at 6 weeks of age were used in four experiments to identify the limiting amino acids in a corn and soybean meal diet. The results indicated that methionine was the first-limiting amino acid for a corn and soybean meal diet. Lysine is the second limiting and tryptophan may be either co-limiting, or third limiting for the young calf. The recommended level of supplemental DL-methionine per day was between 0.022-0.111 g/kg of body weight. The upper level of this range was in excess of the methionine requirement, but it did not seem to be harmful at this stage of calf growth.

Abe, M., and co-workers. 1998. Limiting amino acids for a corn and soybean meal diet in weaned calves less than three months of age. J. Anim. Sci. 76:628-636.