Effect of soy hulls as alternative ingredient on growth performance, carcase quality, nutrients digestibility and intestinal histological features in broilers

The objective of this study is to investigate the effects of increasing levels of soybean hulls in broiler chicken diets on growth performance, carcase composition, organ weights, nutrient digestibility, amino acid digestibility, and intestinal histomorphology to determine the optimal inclusion level for maximising poultry health and performance. A total of 680, 1-day-old male broiler chicks (Hubbard) were randomly assigned to five treatments with eight replicates, each consisting of seventeen birds, and housed in an environmentally controlled room with nipple drinkers and trough feeders. The experimental diets, containing 0%, 2%, 4%, 6%, and 8% dietary soybean hulls (SH), were fed to the broilers for 35 days. During the starter phase, the growth performance of chickens fed 2% SH was not significantly different from the control group, but differences emerged during the later stages. Chickens fed 2% SH showed significantly higher body weight and weight gain compared to higher SH levels. Carcase yield decreased with increasing SH content in the diet, while wing meat yield was highest in birds fed 0% and 2% SH. The relative weights of gizzard, jejunum, and ileum varied significantly among groups. Higher SH levels led to decreased nutrient digestibility but increased excreta nitrogen and ether extract content. Ileal amino acid digestibility varied among SH levels. Intestinal histomorphology revealed significant differences in villi height and crypt depth among groups. Overall, diets with 2% and 4% SH demonstrated superior nutrient utilisation and intestinal health compared to higher SH levels. These findings suggest an optimal inclusion level of SH in broiler diets to optimise performance and intestinal morphology.