Live performance, digestive tract features, and ileal nutrient digestibility in broilers fed diets containing soy hulls

Abstract

This study aimed at determining the impact of dietary soy hulls (SH) addition on growth performance, digestive tract attributes, and apparent ileal digestibility of dry matter (DM), nitrogen, and phosphorus (P) in broiler chickens. Male broilers (Ross 308, n = 224) were assigned to one of four diets, including 0, 20, 40, or 60 g/kg SH, with eight replications per treatment from 0 to 21 d of age in a completely randomised design. Dietary chromic oxide was the indigestible marker for determining the apparent ileal digestibility. Data were subjected to orthogonal polynomial contrasts using the Proc GLM of SAS. Growth performance and small intestine weight and length, and gizzard content pH were not influenced (p > .05) by increasing levels of dietary SH. Increasing the dietary SH level resulted in a linear increase (p < .01) in absolute empty gizzard weight. Relative gizzard weight was greater (p < .05) in birds fed on 60 g/kg SH diet compared to birds fed on 40 g/kg SH diet. Apparent ileal digestibility of nitrogen was not affected (p > .05) by dietary SH inclusion. However, apparent ileal digestibility of DM and P increased linearly (p < .01) with increasing dietary SH levels. In conclusion, the addition of SH up to 60 g/kg improved the ileal digestibility of DM and P and increased gizzard weight without affecting the proportionate small intestine morphology and live performance of broiler chickens at 21 d of age. HIGHLIGHTS Soy hulls did not have any effect on growth Soy hulls increased the digestibility of P Soy hulls increased gizzard weight