Effect of Chinese herbal compound additive on growth performance, serum biochemical indexes and IL-2 mRNA expression in spleen of egg chicks.

The aim of the experiment was to investigate the effect of Chinese herbal compound additive on growth performance, serum biochemical indices and spleen IL-2 mRNA expression of Hy-line Brown egg chicks. A total of 960 one-day-old healthy Hy-line Brown egg chicks were randomly divided into two groups with five replicates per group and 96 chickens per replicate. Egg chicks in control group were fed with basal diet, and those in experimental group were fed with basal diet supplemented with 0.2% Chinese herbal compound additive. The experiment lasted for 42 d. The results showed that compared with control group, the final weight and average daily gain of egg chicks in experimental group were extremely increased (P<0.01), and the feed to gain ratio and mortality rate were extremely decreased (P<0.01). Compared with control group, keel length and tibia length of egg chicks in experimental group were extremely increased (P<0.01), and chest width and hip width were significantly increased (P<0.05). Compared with control group, the content of BUN and TC in serum of egg chicks in experimental group were extremely decreased (P<0.01), the activity of AST was significantly decreased (P<0.05), and the content of IFN-γ and IL-2 were extremely increased (P<0.01). Compared with control group, thymus index, bursa of Fabricius index and spleen IL-2 mRNA expression of egg chicks in experimental group were extremely increased (P<0.01). The study indicates that 0.2% Chinese herbal compound additive in the diet can improve the growth performance, improve the serum biochemical indexes, and promote the development of immune organs and the expression of IL-2 mRNA in spleen of Hy-line Brown egg chicks. [ABSTRACT FROM AUTHOR]