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

Abstract

The objective of this trial was to determine the optimal supplementation level of β-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 β-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 β-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 β-mannanase was demonstrated for the digesta viscosity (p < .01). Increasing β-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 β-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 β-mannanase. In conclusion, this β-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 β-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 dietaryβ-mannanaselevel increased.An increase in villus height of the jejunum was observed with increasing dietary levels ofβ-mannanase.