Standardized ileal digestibility of amino acids in alfalfa meal, sugar beet pulp, and wheat bran compared to wheat and protein ingredients for growing pigs

A total of 11 (8 + 3 for replacement) barrows with an initial BW of 23 kg and fitted with a simple T-cannula at the distal ileum were used in 2 consecutive experiments (Exp. 1 and Exp. 2) to determine the standardized ileal digestibility (SID) ofAA in 7 assay feed ingredients according to 2 consecutive duplicated 4 x 4 Latin square designs. In Exp. 1, 3 corn starch-based assay diets were formulated to contain 170 g CP/kg (as-fed basis) from either soybean meal (SBM), canola meal (CM), or meat-and-bone meal (MBM) and 1 assay diet that contained 136 g CP/kg (as-fed basis) from wheat as commonly used feed ingredients for pigs. In Exp. 2, the pigs were fed 4 assay diets formulated to contain 170 g CP/kg (as-fed basis) from either the same SBM as in Exp. 1 or a combination of this SBM and alfalfa meal (AM), sugar beet pulp (SB), or wheat bran (WB) to compare the SID of AA in these feed ingredients with those used in Exp. 1. The SID of AA in CM was lower compared to SBM (P < 0.05) with intermediate values for MBM and wheat. Among fiber rich feed ingredients, SID values were lower in SB compared to WB (P < 0.05) with intermediate values for AM. In AM, SID values ranged between 29 and 45% for Lys, Cys, Thr, and Phe and between 51 and 71% for Arg, His, Ile, Leu, Met, and Val. In SB, SID values ranged between -21 and 46% for Cys, Thr, Phe, and Val and between 51 and 61% for Arg, His, Ile, Leu, Lys, and Met. In WB, SID values were between 55 and 64% for Lys, Cys, Phe, Thr, and Val and between 68 and 80% for Arg, His, Ile, Leu, and Met. The SID values in WB, SB, and AM provided in the present study may improve diet formulation when these feed ingredients are used in diet formulation for pigs.