Egg production, fertility, and hatchability of breeder hens receiving dietary phytase

An experiment was conducted to determine whether supplemental dietary phytase could support egg production, egg shell quality, fertility, and hatchability in broiler breeder hens on a diet with marginal available phosphorus. During the production period, 27 to 60 wk of age, individually caged broiler breeder hens; were fed four diets with two available phosphorus (AP) concentrations (0.1 and 0.3%) and two phytase levels [0 and 300 phytase units (FTU)/kg]. Phytase increased overall hen-day egg production by 9.8%, as compared with hens consuming a low phosphorus diet without added phytase. Addition of phytase significantly reduced hen mortality regardless of AP levels. Phytase improved bone mineral content and bone density of hens at both AP levels. Supplemental phytase had no significant effect on egg weight or egg specific gravity. The results suggest the possibility of a detrimental interaction of phytase with the 0.1 AP level on hatchability.