Partial replacement of soybean meal with cottonseed meal in diets of broiler chicken sustains performance by upregulating the expression of nutrient transporter genes in small intestine

Abstract

This study investigated the effects of partially replacing soybean meal (SBM) with high-fibre cottonseed meal (HF-CSM) on performance traits and expression of certain nutrient co-transporter genes in the small intestine of male broiler chickens. The HF-CSM had lower CP and AME but higher EE, CF, NDF, and ADF compared to SBM. The free gossypol (FG) concentrations in the HF-CSM-containing diets were well below the limit (100 mg/kg) permitted by the European Union in complete chicken feed. Replacing up to 15 % of SBM in the diets of the experimental chickens with the HF-CSM had an insignificant (P > 0.05) effect on BW, FCR, or European Productivity Index at the time of harvest (42 d), and the 10 % replacement of SBM with HF-CSM (equivalent to 2.5 % inclusion of HF-CSM in the total ration) had effects similar to the all-SBM diet. Viscosity of jejunal digesta increased with the inclusion level of HF-CSM in diet when measured at 24 d (P = 0.048, linear effect) and 48 d (P = 0.001, quadratic effect). Inclusion of the HF-CSM upregulated the expression of nutrient co-transporter genes responsible for absorption of small peptides (PEPT-1), glucose and other hexose sugars (SGLT-1, GLUT-5), and amino acids (EAAT-3) in the small intestine at 24 d (P = 0.001, linear effect) and 42 d (P = 0.001, quadratic effect). Expression of PYY mRNA, associated with satiety regulation, increased with HF-CSM levels in diet at 24 d (P = 0.0001 linear effect) and 42 d (P = 0.001, linear effect), suggesting a potential anorexigenic effect. The study suggests that inclusion of HF-CSM by replacing 10-15 % of SBM on a weight-to-weight basis, which translates into 2.5–3 % inclusion of the former in the whole ration, may sustain the performance of broiler chickens