Abstract
The objective was to determine the influence of amino acid (AA) supplementation during the adaptation period on the ileal digestibility of crude protein and AA in corn and soybean meal (SBM). Six barrows with an initial body weight of 30.9 ± 2.6 kg fitted with a T-cannula in the distal ileum were assigned to a 6 × 6 Latin square design with 6 dietary treatments and 6 periods. Two experimental diets contained corn or SBM as the sole source of AA and an N-free diet was additionally prepared. For AA supplementation groups, an AA mixture consisted of Gly, Lys, Met, Thr, Trp, Ile, Val, His, and Phe was added to the corn diet and the N-free diet at the expense of cornstarch, and an AA mixture of Lys, Met, and Thr was added to the SBM diet. All diets contained 0.5% of chromic oxide. The 6 experimental diets were fed to the pigs for 4 and half days, and the 3 diets containing AA mixture were switched to the respective diets without AA mixture during the following 2 and half days. Ileal digesta were collected during the last 2 days. The addition of AA mixture during the adaptation period caused increased apparent ileal digestibility of Arg and Trp in corn (P < 0.05), but did not affect that in SBM. The addition of AA mixture during the adaptation period caused increased apparent ileal digestibility of Pro and Gly regardless of feed ingredient (P < 0.05), but did not affect that of other AA. All AA except Pro in corn and SBM were unaffected by the addition of AA mixture during the adaptation period. In conclusion, the addition of amino acid during the adaptation period does not affect the standardized ileal digestibility of indispensable amino acids in feed ingredients.
Microbial phytase improves amino acid utilization in young chicks fed diets based on soybean meal but not diets based on peanut meal
