The effects of supplementing diets with Atractylodes macrocephala Koidz rhizomes on growth performance and immune function in piglets

The rhizome of Atractylodes macrocephala Koidz (baizhu in Chinese, AMK) is a well-known traditional Chinese medicine that has long been used as a digestive and tonic. The experiment was conducted to investigate the effect of baizhu powder on the growth performance and immune function of piglets. Duroc x LandracexYorkshire piglets (n=72, half males and half females, 42 days of age, liveweight 14.82 +/- 0.17 kg) were randomly allocated to three treatments: control, control+AMK either ground (GMD=180 mu m), or micronized (GMD=5.59 mu m), for 30 days. The results showed that supplementation with micronized baizhu significantly increased average daily gain (ADG) (P<0.05) and decreased (P<0.05) the feed/gain and diarrhoea ratios compared with the control group. Pigs given 80 mesh baizhu had a lower (P<0.05) diarrhoea ratio than those fed the control diet. Supplementation with 80 mesh baizhu and micronized baizhu significantly increased (P<0.05) both concanavalin- (ConA) and lipopolysaccharide (LPS)-induced splenocyte and peripheral lymphocyte proliferation, serum IgG, IL-1, and IL-2 concentrations (P<0.05) compared with the control group. In addition, supplementation with micronized baizhu significantly enhanced (P<0.05) PR-39 mRNA expression compared with the control group. The results indicate that baizhu could ameliorate metabolic status and regulate immune function to improve the growth performance of piglets, and that super-fine comminution may improve its medicinal efficiency.