PSVI-12 Evaluation of amino acid digestibility in several feed ingredients fed to growing pigs

Abstract

This experiment aimed to determine the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA in common feed ingredients fed to pigs: two sources of soybean meal, two sources of high-fat rice bran, one wheat middlings and one wheat. Six diets were formulated containing one of the above ingredients as the only source of protein and AA. An N-free diet was formulated to assess basal endogenous losses of CP and AA. Titanium dioxide (0.4%) was used in diets as an indigestible marker. Eight barrows (BW: 35.2 ± 1.9 kg) fitted with T-cannulas at the distal ileum were randomly allotted to an 8 x 8 Latin square design with 8 diets and 8 periods. A standard grower diet was used as the eighth diet. Pigs were fed for eight 7-d periods and ileal digesta was collected on d 6 and 7 of each period. Results showed that SID of CP between the two soybean meals (87.2 ± 8.1% vs 88.4 ± 5.7%) and two high-fat rice brans (77.1 ± 4.9% vs 75.8 ± 7.6%) were not different. Averages of SID for CP in wheat middlings and wheat were 63.1 ± 8.3% and 91.2 ± 3.3%, respectively. Differences were detected (P < 0.01) for AID and SID of indispensable AA between the two high-fat rice brans, but not the two soybean meals. The AID and SID of dispensable AA except Glu and Pro were different (P < 0.05) between the two high-fat rice brans. The SID of indispensable AA ranged from 50.1% for Lys to 72.8 % for Met in wheat middlings, and from 81.0% for Lys to 89.4% for Met in wheat. In conclusion, the AID and SID of CP and AA in soybean meals were similar, but differed between the two high-fat rice brans.