Effect of β-mannanase supplementation in low-energy and low-protein diets on performance, intestinal morphology, and fatty liver incidence in laying hens.

Objective: This study aimed to investigate the effect of dietary β-mannanase supplementation in low-energy and low-protein diets containing palm kernel meal and copra meal on productive performance, egg quality, intestinal morphology, and fatty liver incidence in laying hens.

Methods: A total of four hundred 26-wk-old Hy-Line Brown laying hens were allotted to 1 of 5 dietary treatments with 8 replicates. The positive control (PC) diet was prepared with corn and soybean meal, whereas the negative control (NC) diet was formulated with decreased AMEn by 100 kcal/kg and CP by 0.85% than PC diets. High-mannan NC diet was also prepared by inclusion of 2.5% palm kernel meal and 2.5% copra meal, which was designed to contain energy and nutrient concentrations equal to those in the NC diet. Finally, dietary β-mannanase was supplemented to the high mannan NC diet at the levels of 0.05% and 0.10%.

Results: Most productive performance and egg quality were not affected by dietary treatments. For jejunal morphology, villus height:crypt depth (VH:CD) ratio for hens fed PC diets or NC diets was greater (p<0.05) than those fed high-mannan NC diets, but supplementation of β-mannanase in high-mannan NC diets did not affect VH:CD ratio in hens. Hens fed NC diets had a greater (p<0.05) subjective color score in the liver than those fed PC diets or high-mannan NC diets supplemented with 0.05% and 0.10% β-mannanase.

Conclusions: : Most productive performance and egg quality in laying hens were not affected by reduction in dietary energy and protein levels, inclusion of high-mannan ingredients, and dietary β-mannanase supplementation. No considerable benefits of dietary β-mannanase supplementation in low-energy and low-protein diets containing high-mannan ingredients on productive performance and health were observed in laying hens.