Gross responses and apparent ileal digestibility of amino acids and minerals in broiler chicken fed vegetable-based starter diets supplemented with microbial enzymes

Abstract

This study was conducted to investigate the effects of diet and exogenous enzymes on growth responses and micronutrient digestibility of broilers. Day-old broilers (n = 256) were distributed into a 2 × 2 factorial design and were fed on two basal diets: soybean (T1) or canola (T2) meals as such, or supplemented with enzymes up to 21 days. Feed intake (FI) and live weight (LW) to 21 days on the T2 diet was higher (P < 0.001) than that on T1. Feed conversion ratio (FCR) was better (P < 0.01) on T1 than on T2 at 21 days. Enzymes generally improved (P < 0.001) FI, FCR, and LW. The digestibility of histidine was higher (P < 0.05) on T2, but lysine digestibility was higher (P < 0.01) on T1 at 21 days. Histidine, threonine, lysine, valine, isoleucine, and phenylalanine digestibility was improved (P < 0.05) in the supplemented diets. Mineral digestibility was unaffected (P > 0.05) by diet, but enzymes increased (P < 0.05) digestibility of P, K, Mn, and Cu at 21 days. The digestibility of Cu, Zn, and Mg was higher (P < 0.05) on T2, whereas Ca digestibility was greater (P < 0.05) on the T1 diet. Broilers' growth responded positively to enzyme diets, probably due to improvement in nutrient digestibility.