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 bo ne strength characteristics and egg production of white leghorn layers were investigated. 2. The shear fracture energy increased in the tibi a 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 o f the tibia and radius increased for the non-egg producing birds at 72 weeks. 4. Bird body weight, food consumption, egg weight, and egg pro duction all decreased at 400 mg/kg boron. 5. Boron concentrations in t he breast, liver, thigh and bone tissue increased with increasing conc entrations of supplemental boron.