Effects of Dietary Tea Polyphenols on Epigallocatechin Gallate, Catechin, Egg Quality and Production of Gallus domestiaus

Abstract

Effect of dietary tea polyphenol (TP) on the content of epigallocatechin gallate (EGCG), catechin (C) in egg yolk, and impact on egg quality and production was investigated. For this purpose, 315 healthy Gallus domestiaus aged 42 weeks were selected and randomly divided into 7 groups. The experimental group added 0.02, 0.05, 0.09, 0.14, 0.19 and 0.24% TP to the basic diet. The control group (CK) was fed basal diet. After 10, 20 and 30 days, 15 eggs were randomly selected from each group for egg quality testing, and 20 eggs were selected for EGCG and C content test in the yolk. The results showed that in the 0.24% TP group, the content of EGCG in egg yolk was significantly higher than that of CK group and the 0.02, 0.05, 0.09 and 0.14% TP groups (P < 0.05), and reached the highest on the 30th day (19.171μg/g). The content of C in egg yolk was significantly higher than that in CK group and the 0.02, 0.05, 0.09 and 0.14% TP groups (P < 0.05); and reached the highest on 30th day (7.071 μg/g). The egg weight of the 0.14% TP group on the 10th day and of the 0.19% TP group on the 20th day were significantly lower than that of the CK group (P < 0.05); the egg yolk weight of 0.14% TP on the 10th and 20th days were significantly lower than that of the CK group (P < 0.05). On the 30th day, compared with the control group, the egg weight of the 0.14% TP group was significantly reduced (P < 0.05), the egg yolk color of 0.05 and 0.14% TP groups was significantly increased (P < 0.05). During the whole experiment, the egg production of 0.24% TP group was significantly higher than that of control group (P < 0.05). In conclusion, adding high concentrations of TP can increase the content of EGCG and C in the yolk; however, it has a certain impact on egg weight, yolk color and eggshell thickness. Adding high concentrations of TP may increase egg production. © 2021 Friends Science Publishers