The Effect of Supplementing Tea Polyphenols on Yolk Cholesterol and Production Performance of Laying Hens During the Egg-laying Period

ABSTRACT This study aimed to investigate the effect of supplementing 300 mg/kg tea polyphenols (TP) on yolk cholesterol content and production performance of laying hens during the egg-laying period. A total of 600 Roman laying hens aged 24 weeks were randomly divided into two dietary treatment groups. The feeding experiment lasted for 48 weeks. Layers fed basal diet supplemented with 0 (control group) and 300mg/kg TP (TP group) diet, respectively. The yolk cholesterol content, laying performance, and egg quality were determined at 28, 38, 48, 58, and 68 weeks of age. The yolk cholesterol content in the TP group was significantly decreased at 28-68 weeks of age (p<0.01), compared to the control group. There was a significant increase in laying rate in the TP group at 38 weeks of age (p<0.05), compared to the control group, while no significant differences during the other laying periods were obtained (p>0.05). The FCR significantly decreased in the TP group at 38 weeks of age whereas AEW significantly increased in the TP group at 58 weeks of age (p<0.05). Similarly, the eggshell thickness and eggshell strength in the TP group significantly increased (p<0.05), compared with the control group at 38 weeks of age. The albumen height and Haugh unit significantly increased at 28 weeks of age (p<0.05). In conclusion, the results showed that the diet supplemented with 300 mg/kg TP had positive effects on production performance of layers during the egg-laying period, and could lessen yolk cholesterol content significantly at 28-68 weeks of age.

摘要 本研究旨在探究日粮中添加300 mg/kg茶多酚（tea polyphenols, TP）对产蛋期罗曼蛋鸡蛋黄胆固醇含量与生产性能的影响。选取600只24周龄的罗曼蛋鸡，随机分为2个日粮处理组。本饲喂试验周期为48周，两组蛋鸡分别饲喂添加0（对照组）与300 mg/kg TP的基础日粮（TP组）。分别于28、38、48、58及68周龄，测定蛋黄胆固醇含量、产蛋性能与蛋品质。相较于对照组，TP组蛋鸡在28~68周龄时蛋黄胆固醇含量极显著降低（p<0.01）。TP组在38周龄时产蛋率较对照组显著升高（p<0.05），其余产蛋阶段无显著差异（p>0.05）。TP组在38周龄时料蛋比（FCR）显著降低，而在58周龄时平均蛋重（AEW）显著升高（p<0.05）。同样，相较于对照组，TP组在38周龄时蛋壳厚度与蛋壳强度均显著提升（p<0.05）；28周龄时蛋清高度与哈氏单位（Haugh unit）显著升高（p<0.05）。综上，本研究结果表明，日粮中添加300 mg/kg TP可对产蛋期蛋鸡的生产性能产生积极影响，并可在28~68周龄时极显著降低蛋黄胆固醇含量。