Effects of dietary supplementation of β-mannanase on performance and egg quality in laying hens
The objective of the experiment was to evaluate effects of dietary supplementation of β-mannanase (Hemicell®) on productive performance, egg quality, and fecal moisture content in laying hens from 20 to 35 weeks of age. A total of 375 Isa Brown’s hens (1615.6 ± 76.4 g/bird) were randomly assigned to 5 treatments in a completely randomized design. The 5 dietary treatments included (1) basal diet with a level of 2800 kcal ME and no β-mannanase supplementation (HE, Control), (2) HE + 32 units of β-mannanase/g of feed, (3) HE + 64 units of β-mannanase/g of feed, (4) basal diet with a level of 2700 kcal ME (LE) + 32 units of β-mannanase/g of feed, and (5) LE + 64 units of β-mannanase/g of feed. Each treatment was replicated with 25 cages of 3 hens each. All diets were in meal form and contained no antibiotics. The addition of β-mannanase to HE diets did not affect the egg production of birds as compared with the control (P > 0.05). The birds fed LE diets with β-mannanase had the same egg production as those fed the control and β-mannanase-supplemented HE diets (P > 0.05). Differences in egg weight, egg quality, survival rate, and fecal moisture content were not significant among the treatments (P > 0.05). Briefly, addition of β-mannanase (32 units/g of feed) to LE diets would be beneficial for layers during the early laying period as it resulted in the same performance and egg quality as the HE diets without β-mannanase supplementation.