Serum Mineral Profile of Laying Hens During Peak Production Phase in Poultry Farms in Ogun State

Mineral homeostasis plays a critical role in supporting egg production, shell quality, and metabolic functions in laying hens during the peak production phase. Deficiencies or imbalances in calcium, phosphorus, magnesium, sodium, potassium, and trace elements can result in reduced laying performance, poor shell integrity, and increased susceptibility to metabolic disorders. This study assessed the serum mineral profile of laying hens at peak production in commercial farms in Ogun State, South West Nigeria. Blood samples were collected from 120 hens aged 24 to 36 weeks across three farms using different commercial layer diets. Serum was analysed for calcium, phosphorus, magnesium, sodium, potassium, copper, zinc, and selenium using atomic absorption spectrophotometry and colorimetric kits. Results showed that 22.5 percent of hens had serum calcium below the expected peak production range of 13 to 20 mg/dL, while phosphorus was within acceptable limits in all samples. Serum zinc was deficient in 18.3 percent of hens, and selenium was below optimal levels in 30 percent. Farm diet formulation had significant effects on mineral status across all measured analytes. Hens with suboptimal calcium and zinc showed significantly higher rates of thin-shelled and broken eggs. These findings suggest that serum mineral monitoring should be incorporated into flock health management programmes in commercial layer farms in Ogun State and across the South West region. Keywords: serum minerals, laying hens, calcium, peak production, Ogun State.