Influence of dietary boric acid and ascorbic acid on performance, egg traits, cholesterol and bone parameters of laying hens

This study was conduct to investigate the impact of dietary boric acid (BA), includes 17.5 % boron, ascorbic acid (AA) and combined of boric acid and ascorbic acid (AABA) on performance, egg traits, blood serum and egg yolk cholesterol concentrations and some bone parameters of laying hens. In total, 160 Hyline-White 98 layers aged 59 weeks were allocated four treatments with ten replicates. Dietary treatments included the basal diets as control, AA-supplemented diets with an inclusion level of 200 mg/kg AA, and BA-supplemented diets with an inclusion level of 120 mg/kg BA and AABA-supplemented diets with an inclusion level of 200 mg/kg AA + 120 mg/kg BA. The experimental period lasted 16 weeks. Feeding ascorbic acid and boric acid diet did not significantly affect body weight, feed efficiency, egg weight, egg shell index, egg breaking strength, egg shell thickness, egg albumen index, egg yolk index, egg Haugh unit, egg yolk weight, tibia crude ash and phosphorus. Egg production increased (P<0.05) with ascorbic acid supplementation at only 11-12th weeks. There was a significant (P<0.05) increasing in feed consumption at first two weeks period. Hen serum cholesterol (P=0.001) concentrations decreased with ascorbic acid and boric acid supplementation single or together, while egg yolk cholesterol did not affect. Ascorbic acid and boric acid also significantly increased tibia calcium levels (P<0.05). Higher liver (P<0.001) and egg yolk (P<0.001) boron concentrations were detected in hens receiving BA and AABA diets. This study demonstrated that ascorbic acid and/or boric acid may have beneficial effects on Ca mobilization from the bone.