Influence of corn conditioning temperature and enzyme supplementation on growth performance, nutrient utilisation and intestine morphology of broilers fed mash corn-soy diets

Abstract

Two trials were conducted to investigate the effects of different corn conditioning temperature and enzyme supplementation on nutrient utilisation, growth performance, and small intestine morphology in broiler chickens. In trial one, nutrient utilisation were determined in basal diets. These diets contained unconditioned or conditioned corn (temperatures 55, 70 and 85 °C) supplemented with enzyme (Rovabio®) at the levels of 0 and 0.5‌ g/kg. Total excreta collection was performed with 144 chicks in 8 treatments with 6 replicates and 3 birds each, during 7–9 d. In trial two, 576 day-old broilers were distributed in 8 treatments, 6 pens and 12 chicks each. Birds were fed with diets containing conditioned corn in aforementioned temperatures and enzyme levels. A completely randomised design with 4 × 2 factorial arrangement was used in both trials. Conditioning of corn and enzyme supplementation had no significant effects on apparent metabolisable energy (AME) of corn and apparent total tract retention (ATTR) of corn nitrogen (N). In second trial, no significant differences were observed in growth performance of broilers during 1–24 d. Feed conversion ratio (FCR) in birds fed diets containing conditioned corn at 85 °C was significantly higher than that of 55 and 70 °C during 1–10 d. Corn conditioning significantly increased villus width (VW) and crypt depth (CD) but decreased VW:CD ratio. Enzyme supplementation increased jejunum villus height (VH), VW and ileal lactobacillus count and decreased pancreas weight at 24 ‌d (p‌ <‌ .05). Generally, corn conditioning and enzyme supplementation did not significantly affect growth performance and carcase traits of broilers during 1–24 d, but improved histology and microbial population of small intestine. HIGHLIGHTS Conditioning of corn used in mash diets of broiler chickens increased the population of bifidobacteria. Enzyme supplementation to the diets of broilers increased the height and width of intestinal villi. Enzyme supplementation to the diets of broilers decreased relative weight of pancreas.