Effects Of Dietary Herba Houttuyniae On Performance, Nutrient Metabolism And Immunity In Broilers

Herba Houttuyniae is a kind of Chinese herbal medicine with multiple functions such as anti-bacterial, anti-inflammatory, anti-virus and enhancing immunity and it has been widely used in animal disease control. For investigating effects of dietary Herba Houttuyniae on growth, nutrition metabolism, physiological and biochemical index and immune status in broiler, three experiments designed as 1×4 factorial were conducted with the healthy 7-28d-old Hubbard broiler chickens with similar weight in this thesis. Each experiment included the control group (no Herba Houttuyniae), the treatment groupⅠ,ⅡandⅢ(adding 0.3%, 0.4% and 0.5% Herba Houttuyniae in feed respectively).In experiment 1, 144 7-d-old birds uniformly allotted to 4 groups with 12 replicates each group, were conducted a three-week feeding trial and one-week metabolism test. The results showed that daily weight gain and daily feed intake of the three treatment groups slightly increased from 1.19% to 6.44%, 0.44% to 4.92 % (P>0.05), feed conversion ratio lower from 1.64% to 8.16% respectively (P>0.05), compared with the control group; crude fiber apparent metabolic rate of the treatment groupⅡis significantly higher than those of the control group and the treatment groupⅠ(P<0.01) or the treatment groupⅢ(P<0.05), and there was no significant changes between the treatment groupⅠ,Ⅲand the control group (P>0.05). Significant difference of apparent metabolic rate of other nutrients, spleen index and bursa of Fabricius index was not observed among the groups (P>0.05). The results suggested that the influences of Herba Houttuyniae on broiler's growth, nutrition metabolism and immune organs are not significant.In experiment 2, 32 7-d-old chickens equally separated into 4 groups and 2 replicates each group, were fed for three weeks then to test the blood glucose levels and the TP, ALB, GLO, TC, TG, T3, T4, BUN contents and GOT , GPT activity in serum after the birds were empty stomach for 12 hours. The results showed that serum TG levels of the treatment groupⅠ,ⅡandⅢwere significantly lower than that of the control group (P<0.05); the serum GLO concentration of the treatment groupⅡis significantly higher than these of the control group and the treatment groupⅠ,Ⅲ(P<0.05); The remaining indexes are not significant different between groups (P>0.05). The results implied that dietary Herba Houttuyniae can significantly reduce broiler serum triglyceride levels, and raise broiler lipid decomposition metabolism. In experiment 3, total 16 broilers divided into 4 groups, were fed for three weeks then to analysis the gene transcription changes of INF-γin spleen and the MIP-1βin mucous membrane of small intestine by real-time quantitative PCR, according theβ-Actin. The results showed gene transcription levels of INF-γin spleen and MIP-1βin mucous membrane of small intestine of three treatment groups are significantly higher than those of the control group (P<0.01). The results indicated that Herba Houttuyniae can significantly improve the broiler's immunity.This study suggested that dietary Herba Houttuyniae has no obvious negative effects on the broiler growth and metabolism, and improve their lipid metabolism as well as enhance their immune response capacity. The thesis is a valuable exploration on Herba Houttuyniae application in broiler rearing.