• KSBB Journal
• /
• v.30 no.2
• /
• pp.58-62
• /
• 2015

A 3-weeks feeding trial with 288 laying hens were conducted to determine the efficacy of lecithin-free egg yolk at different levels of dietary Ca on performance and Ca absorption. Laying hens were divided into 6 groups according to calcium level and testing agent; 0% calcium feed (A), 0.2% calcium feed (B), 0.4% calcium feed (C, normal feed), 0.6% calcium feed (D), 0.4% calcium feed + 0.2% egg byproduct (C+0.2), 0.4% calcium feed + 0.4% egg byproduct (C+0.4). The final body weight gain of C+0.2 and C+0.4 groups were higher by 1.5% and 7.4% respectively than group C. Tibia ash contents did not show significantly difference, but calcium contents increase (p<0.05) in C+0.2 and C+0.4 groups. Parallel undecalcified tibia joint sections were stained for calcium absorption by the von Kossa's stain. This result show that lecithin free egg byproduct supplementation to normal calcium feed improved growth performance and calcium utilization in laying hens.