Abstract
The paper aimed to evaluate the effects of dietary inclusion of green tea powder (GTP) on laying performance, egg quality, and blood biochemical parameters of laying hens. A total of 240 Jingfen No. 6 laying hens (age, 24 wk) were randomly allocated into 4 groups: control group (CON, basal diet), GTP0.5, GTP0.75, and GTP1.0 (basal diet included 0.5, 0.75, and 1.0% GTP, respectively). Each group has 5 replicates with 12 birds each. The feeding trial lasted 8 wk. The results showed that the hen-day egg production rate in GTP0.5 and GTP 0.75 group was higher than that of GTP1.0 group (P < 0.05), hen-day egg production rate in the GTP1.0 group was lower compared to the CON group (P > 0.05), the feed conversion ratio (FCR) in the GTP0.75 group was lower than that in CON and GTP 1.0 group (P < 0.05) during the entire experimental period. Albumen height and Haugh unit were higher in the GTP0.75 and GTP1.0 group compared to the CON group at d 56 (P < 0.05). At the end of experiment, plasma TG content in the GTP0.75 and GTP1.0 group was lower than that in the CON group (P < 0.05), the T-CH concentration in the GTP0.5 and GTP0.75 group was lower compared to the CON group (P < 0.05), plasma LDL-C and CORT concentrations were decreased by dietary GTP supplementation (P < 0.05), the HDL-C and BUN concentrations in the GTP0.75 and GTP1.0 group were higher than that in the CON group (P < 0.05). The antibody titers of H5N1 in the GTP0.75 and GTP1.0 group, and H7N9 in the GTP1.0 group were lower than that in the CON group (P < 0.05). In conclusion, dietary GTP inclusion could affect laying performance, regulate lipid metabolism, and have no favorable influence on antibody titers of H5N1 and H7N9, herein, dietary 0.5% GTP inclusion is suggested for Jingfen No. 6 laying hens during the peak laying period.