Kim Jong Hyuk, Lee Han Kyu, Yang Tae Sung, Kang Hwan Ku, Kil Dong Yong
Department of Animal Science and Technology, Chung-Ang University, Anseong 17546, Korea.
Poultry Research Institute, National Institute of Animal Science, Rural Development Administration, Pyeongchang 25342, Korea.
Asian-Australas J Anim Sci. 2019 Apr 15;32(9):1407-1413. doi: 10.5713/ajas.19.0063. Print 2019 Sep.
This experiment aimed to investigate the effect of different sources and inclusion levels of dietary fat on productive performance and egg quality in laying hens raised under hot environmental conditions.
A total of 480 Hy-Line Brown laying hens at 31 wk of age were randomly allotted to 1 of 5 experimental diets. The control diet contained 2,800 kcal/kg AMEn with no fat addition. Four additional diets were prepared by adding 2.0 or 4.0% of animal fat (AF) or soybean oil (SO). Energy and nutrient concentrations were consistent among all diets. Diets were fed to hens for 4 weeks. Average daily room temperature and humidity were 26.7 ± 1.52°C and 77.4 ± 4.50%. The heat stress index was approximately 76, indicating that hens were raised under heat stress conditions.
Final BW was greater (p<0.05) for hens fed diets containing 2.0 or 4.0% AF than for those fed the control diet or diets containing 2.0 or 4.0% SO. The BW gain and feed intake were greater (p<0.05) for hens fed diets containing additional AF or SO than those fed the control diet. Eggshell thickness were the greatest (p<0.05) for hens fed the control diet, but the least (p<0.05) for hens fed diets containing 4.0% SO. Egg yolk color was the greatest (p<0.05) for hens fed to the control diet, but the least (p<0.05) for hens fed diets containing 4.0% SO.
Inclusion of supplemental fat (AF and SO) in diets exhibits preventative effects on BW loss for hens raised under hot environmental conditions when energy and nutrient concentrations in diets were maintained. The effects were greater for AF than for SO. However, inclusion of supplemental fat in diets decreases eggshell thickness and egg yolk yellowness, possibly due to a reduction in Ca absorption and intake of egg yolk colorants.
本试验旨在研究热环境条件下饲养的蛋鸡日粮中不同来源和添加水平的脂肪对生产性能和蛋品质的影响。
将480只31周龄的海兰褐蛋鸡随机分配到5种试验日粮中的1种。对照日粮含2800千卡/千克表观代谢能，不添加脂肪。通过添加2.0%或4.0%的动物脂肪（AF）或大豆油（SO）配制另外4种日粮。所有日粮的能量和营养浓度一致。日粮饲喂母鸡4周。平均每日室温及湿度分别为26.7±1.52℃和77.4±4.50%。热应激指数约为76，表明母鸡处于热应激条件下饲养。
饲喂含2.0%或4.0%AF日粮的母鸡末体重高于（p<0.05）饲喂对照日粮或含2.0%或4.0%SO日粮的母鸡。饲喂添加AF或SO日粮的母鸡体重增加和采食量高于（p<0.05）饲喂对照日粮的母鸡。饲喂对照日粮的母鸡蛋壳厚度最大（p<0.05），但饲喂含4.0%SO日粮的母鸡蛋壳厚度最小（p<0.05）。饲喂对照日粮的母鸡蛋黄颜色最深（p<0.05），但饲喂含4.0%SO日粮的母鸡蛋黄颜色最浅（p<0.05）。
当日粮能量和营养浓度保持不变时，日粮中添加脂肪（AF和SO）对热环境条件下饲养的母鸡体重损失有预防作用。AF的效果大于SO。然而，日粮中添加脂肪会降低蛋壳厚度和蛋黄颜色，可能是由于钙吸收减少和蛋黄色素摄入量减少所致。
