| The summer and autumn tea resources in China are abundant,and the utilization of summer and autumn tea is relatively rare.With the development of the prohibition of antibiotics in animal feed and the green and healthy production of livestock and poultry,it is important to explore the usage of summer and autumn tea in animals feed.In the thesis,the effects of green tea powder from summer and autumn tea on the production performance,egg quality,blood biochemical indexes and intestinal health of Wannan yellow chicken during late laying period were studied.A total of 108 62-week-old Wannan yellow chickens were randomly allocated into control group(GTP0),GTP0.5 group,GTP1.0 group and GTP1.5 group,with 3 replicates in each group,and 5 hens per replicate.The control group was fed a basic diet of corn-soybean meal,and the GTP0.5 group,GTP1.0 group and GTP1.5 group were fed diets containing 0.5%,1.0% and 1.5% green tea powder,respectively.The trial lasted 8 weeks.The results of the study were as follows:1.Laying performance: Dietary green tea powder supplementation significantly decreased the egg production rate in the experimental group compared to the control group(P<0.05).There was no significant difference on average daily feed intake and feed conversion rate between GTP1.0 group and control group(P>0.05),however,the average egg weight in the GTP1.0 group was higher than that of control group(P<0.05).The average egg weight and average daily feed intake in the GTP0.5 and GTP 1.0 group was lower than that of control group(P<0.05),however,the feed conversion rate in the GTP0.5 and GTP1.0 group was higher than that in control group(P<0.05).2.Egg quality: There was a downwards trend on the eggshell strength and eggshell thickness with increasing dietary green tea powder supplementation.However,there were no significant differences on the egg quality parameters such as eggshell shape,yolk color,albumen height and Haugh unit among these groups.3.Immune level and biochemical index: Dietary green tea powder supplementation had no significant effects on the serum antibody titers of H5N1,H7N9,H9N2 and ND,and there was a downwards trend on the serum antibody titers of ND and H5N1 with increasing dietary green tea powder supplementation.The antibody titers of H7N9 and H9N2 in the GTP0.5 group were higher than those in the control group(P>0.05).Dietary green tea powder supplementation decreased the total cholesterol and triglycerides contents and increased the high density lipoprotein content in Wannan yellow chicken during late laying period(P>0.05).The concentration of glutathione peroxidase was increased by dietary green tea powder supplementation(P<0.05).4.Slaughtering performance: There was a downwards trend on the percentage of abdominal fat in the experimental group compared to the control group.The percentage of abdominal fat in the GTP1.5 group was lower than that of control group(P<0.05).However,no significant difference was found on dressed percentage and percentage of half-eviscerated yield of Wannan yellow chicken during late laying period.5.Intestinal morphology and flora structure: There were no significant differences on the villi height,crypt depth and villi height/crypt depth in the part of duodenum and jejunum in the experimental group compared to the control group(P>0.05).The cecal microbial diversity was reduced by dietary green tea powder supplementation in the experimental group compared to the control group(P>0.05).6.Hatching performance: There were no significant differences on fertility and hatchability of the fertile eggs among these groups(P>0.05).However,the uniformity of chickens from fertile eggs is better than that of the control group.In summary,Dietary green tea powder supplementation could reduce the egg production rate,feed utilization rate,eggshell strength and eggshell thickness,however,and help to reduce blood total cholesterol and triglyceride contents,and increase high-density lipoprotein concentration,and reduce percentage of abdominal fat.Supplementation with1.5% green tea powder in diet could help to improve the uniformity of chickens from fertile eggs. |
PDF Full Text Request