Long term effects of boron on layer bone strength and production parameters.

1. The effects of dietary boron (0, 50, 100, 200, and 400 mg/kg) on bone strength characteristics and egg production of white leghorn layers were investigated. 2. The shear fracture energy increased in the tibia and radius at 72 weeks for birds started on the 200 mg/kg supplement at 32 weeks of age. 3. The shear force, stress, and fracture energy of the tibia and radius increased for the non-egg producing birds at 72 weeks. 4. Bird body weight, food consumption, egg weight, and egg production all decreased at 400 mg/kg boron. 5. Boron concentrations in the breast, liver, thigh and bone tissue increased with increasing concentrations of supplemental boron.