Effects of Dietary Gardeniae Fructus on Growth Performance,Plasma Biochemical Indices,Immune Function and Antioxidant Capacity of Yellow-Feathered Broilers
This experiment was conducted to investigate the effects of different dietary levels of gardeniae fruc-tus on growth performance,organ indices,plasma biochemical indices,jejunal mucosal cytokine contents and liver and kidney antioxidant indices of yellow-feathered broilers aged from 1 to 51 days,and to determine the optimal supplemental level of gardeniae fructus in diets for yellow-feathered broilers.A total of 720 one-day-old Mahuang broiler chickens with initial body weight of(38.44±0.06)g and good health were randomly divided into 5 groups according to the principle of body weight uniformity,and fed the basal diets supplemented with 0(control group),0.4%,0.8%,1.2%and 1.6%gardeniae fructus,respectively,with 6 replicates in each group and 24 chickens(half male and half female)in each replicate.The experiment lasted for 51 days.The results showed as follows:1)the average daily feed intake of yellow-feathered broilers had linear and quadratic changes with the increase of dietary gardeniae fructus level(P<0.05).Compared with the control group,the final body weight and average daily gain in 0.4%and 0.8%gardeniae fructus groups were increased(P>0.05),and the ratio of feed to gain in 0.4%,0.8%and 1.6%gardeniae fructus groups was significantly de-creased(P<0.05).2)The lung index of yellow-feathered broilers had a quadratic change with the increase of dietary gardeniae fructus level(P<0.05).Compared with the control group,the lung index in gardeniae fruc-tus groups was significantly increased(P<0.05).3)With the increase of dietary gardeniae fructus level,the plasma total protein content of yellow feather broilers had linear and quadratic changes(P<0.05),the plasma contents of total bilirubin and creatinine were linearly increased(P<0.05),and the plasma creatine kinase ac-tivity had linear and quadratic changes(P<0.05).Compared with the control group,the plasma glutamic oxal-acetic transaminase activity in 0.4%gardeniae fructus group was significantly increased(P<0.05),and the plasma lactate dehydrogenase activity in 0.4%,0.8%and 1.6%gardeniae fructus groups was significantly in-creased(P<0.05).4)Compared with the control group,the secreted immunoglobulin A(sIgA)content in jejunal mucosa of yellow-feathered broilers in 1.6%gardeniae fructus group was significantly increased(P<0.05).5)With the increase of dietary gardeniae fructus level,the total antioxidant capacity in liver and the to-tal superoxide dismutase(T-SOD)activity in kidney of yellow-feathered broilers had linear and quadratic changes(P<0.05),the T-SOD activity in liver had a quadratic change(P<0.05),and the malondialdehyde content and the glutathione peroxidase activity in kidney were increased linearly(P<0.05).In conclusion,di-etary gardeniae fructus can increase the growth performance,sIgA content in jejunal mucosa and antioxidant enzyme activity in liver and kidney of yellow-feathered broilers;based on the growth performance indices as the main evaluation indices,the optimal supplemental level of gardeniae fructus in diets for yellow-feathered broilers is 0.66%to 0.95%according to the quadratic regression model.[Chinese Journal of Animal Nutri-tion,2024,36(11):6977-6988]