Nutrient composition and ileal amino acid (AA) digestibility of soybean hulls (SH) collected from four solvent extraction plants (SH1, SH2, SH3 and SH4) in Pakistan, were compared using laboratory analyses and animal studies. For animal studies, 200, day-old birds were randomly divided among five feeding groups, each comprising of four replicates of ten birds in a completely randomized design (CRD) using general linear model (GLM) procedure of the statistical analysis system. There was significant (P > 0.05) effect of SH source on percent crude protein (CP), fat, ash, fiber, and non-starch polysaccharide (NSP) of SH originated from different resources. The mean CP percentage of the four SH sources was determined to be 11.6% in SH3 to 13.52% in SH1 (P < 0.05) on as-fed basis. The ileal amino acid digestibility (IAA) of SH obtained from different commercial plants were significantly different. In general, SH1 and SH4 fed birds had significantly higher ileal amino acid digestibility as compared to those fed SH2 and SH3 on all recorded stages of the experiment. Substantial differences (P < 0.05 to P < 0.01) were observed for the digestibility of lysine, methionine + cystine, glycine + serine, leucine and phenylalanine of SH procured from different resources. It is concluded that nutritive values and digestibility vary among SH originated from different sources and contribute differently to performance of the birds. Overall, nutritive value of SH1 was superior in contrast to that of SH2, SH3 and SH4 and contents of IAA digestibility.

Key words: Amino acid digestibility, ileal, amino acid digestibility, broiler, soybean hulls