고온 환경에서 사료내 트립토판과 나이아신의 단독 혹은 혼합 첨가가 산란계의 생산성, 난품질, 지방간 지표 및 혈액성상에 미치는 영향

초록

This experiment investigated the interactive effect of dietary tryptophan (Trp) and niacin supplementation on productive performance,egg quality, fatty liver incidence, and serum measurements of laying hens raised under heat-stress conditions. 384 25-week-old LohmannBrown-Lite laying hens were randomly allotted to 1 of 4 dietary treatments with 8 replicates. Each replicate had 12 birds. The basaldiet with no supplementation of Trp and niacin was formulated to meet or exceed the nutrient and energy requirement. Dietary treatments included 2 levels of supplemental Trp (0 and 0.16%) and 2 levels of supplemental niacin (0 and 0.03%) in a 2 × 2 factorial arrangement. All hens were raised under a cyclic heat stress condition at 31.4 ± 1.17℃, 86.0 ± 4.28% for 8 h/d and 26.7 ± 1.10℃, 61.7 ± 6.34%for the remaining time. The experiment lasted for 10 wk. Results indicated no main effects and interactions of dietary Trp and niacinwere observed for productive performance. Likewise, no interactions were found for eggshell strength, eggshell thickness, eggshell color,egg yolk color, and haugh unit. As the main effects, dietary supplementation of 0.03% niacin decreased (P < 0.05) egg yolk colorbut increased (P < 0.05) haugh unit. However, dietary supplementation of 0.16% Trp did not affect egg quality. No main effects andinteractions of dietary Trp and niacin were observed for fatty liver incidence and serum measurements. In conclusion, dietarysupplementation of Trp and niacin at the current level may exert no positive effects on productive performance, egg quality, fatty liverincidence, and serum measurements of laying hens raised under heat-stress conditions.

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