Egg quality and performance responses to dietary calcium and phosphorus concentrations in laying hens of different ages

Context The balance of dietary calcium (Ca) and phosphorus (P) plays a crucial role in laying hen performance and egg quality, yet optimal concentrations for these minerals are not well-defined, particularly across different ages. Aims This study aimed to evaluate the effects of dietary Ca and P concentrations, along with hen age, on egg performance and quality in Lohmann Brown hens. Methods In total, 432 Lohmann Brown hens, aged 30–42 weeks, were distributed in a completely randomized design with a central composite rotatable design (22 + central and axial points), resulting in nine treatments with eight replicates and six birds per experimental unit. The data were analyzed via ANOVA, regression models, and the Tukey–Kramer test (α = 0.05). Key results Increasing dietary Ca concentrations reduced feed intake and improved the feed conversion ratio (FCR), while enhancing eggshell quality. Specific gravity and eggshell weight showed a quadratic response to dietary P, with optimal values of 0.43% and 0.36% respectively. Age negatively affected egg production and egg mass, but increased yolk percentage and eggshell thickness. The optimal yolk percentage was achieved with either low Ca and high P or high Ca and low P, whereas the maximum albumen percentage was reached with 4.1% Ca or 0.34% P. Conclusions This study has highlighted the importance of optimizing dietary Ca and P concentrations according to the hens’ laying phase to enhance both productivity and egg quality. Implications The findings have provided valuable insights for formulating diets that support the health and efficiency of laying hens, leading to improved egg production and quality in commercial poultry systems.