A dose-response study to evaluate the effects of pH-stable -mannanase derived from Trichoderma citrinoviride on growth performance, nutrient retention, and intestine morphology in broiler chickens

The objective of this trial was to determine the optimal supplementation level of -mannanase preparation enzyme from Trichoderma citrinoviride on growth performance, apparent total tract retention of nutrients and gut health of broiler chickens. A total of 600 broiler chickens (Ross 308) were randomly allotted to four treatments on the basis of similar body weight. The dietary treatments included a corn soybean-based diet supplemented with 0 (control), 1200, 2400, or 4800 MNU/kg -mannanase preparation. The experimental diets were fed in crumbles in phase 1 (1 to 14 days) and pellets in phase 2 (15 to 35 days). The linear and quadratic contrasts were used to compare effects of increasing dietary -mannanase preparation levels. The overall result indicated a linear increase (p<.01) in overall body weight gain and feed conversion ratio. The retention of N, GE, soluble none starch polysaccharide, and insoluble none starch polysaccharide linearly improved in the phase 1 and phase 2 (p<.05). A linear response to increasing dietary -mannanase was demonstrated for the digesta viscosity (p<.01). Increasing -mannanase level in the diets increased the concentration of mannose, galactose, and glucose in ileum and caecum. An increase in villus height of the jejunum with increasing dietary levels of -mannanase was observed (linear, p<.05). In addition, villus height of the duodenum and the ileum tended to increase (linear; p=.06) and with increase in dietary -mannanase. In conclusion, this -mannanase has potential to improve the growth performance, apparent total tract retention of nutrients and gut health of broiler chickens fed a corn SBM-based diet.HighlightsDietary -mannanase improved the growth performance of broiler chicks by increasing the retention of gross energy, soluble NSP and insoluble NSP.The viscosity of digesta in ileum was linearly increased as dietary-mannanaselevel increased.An increase in villus height of the jejunum was observed with increasing dietary levels of-mannanase.