The Effects Of Allicin On Immune Function And Growth Performance Of Laying Hens

To investigate the effects of allicin on immune function and growth performance of laying hens, 200 healthy one-day-old female Hy-Line White layer hens were divided randomly into control group(CG, basal diets without allicin, low-dose groups(LG, basal diets with allicin 50mg/kg), medium-dose groups(MG, basal diets with allicin 100mg/kg) and high-dose group(HG,basal diets with allicin 150mg/kg) from 8 days to 42 days of age, respectively. At the end of experiment, the immune organ index and daily body weight gains and feed/weight ratio of of 20 layer hens in each group were evaluated. The activity of superoxide dismutase(SOD), glutathion peroxidase(GSH-Px), and contents of malondialdehyde(MDA) in serum and immune organ; the levels of immunoglobulin G(Ig G), Ig M, Ig A, complement factor 3(C3), C4,interleukin-2(IL-2), factor-α(TNF-α) and the HI antibody titer against Newcastle disease virus(NDV) in serum; the number of white blood cell(WBC), total lymphocyte count, the T lymplocytes ANAE+ in peripheral blood cells; the total of the erythrocyte C3 b RR and ICR ratio were detected. The remaining 160 layer hens were stopped to feed allicin and raised to 200 days. The rate of producing eggs, feed/egg ratio, abnormal eggs rate were calculated. The results indicated that:(1) With the increasing dose of allicin, the activity of SOD and GSH-Px in allicin-treated groups were significantly increased than those in CG(P<0.05; P<0.01), while the contents of MDA in all allicin-treated groups was significantly decreased than those in CG(P<0.05; P<0.01) in serum and immune organ of layer hens. It indicated that allicin could improve the ability of antioxidant.(2) With the increasing dose of allicin, the organ index of spleen, thymus and bursa of Fabricius in allicin-treated groups were significantly increased than those in CG(P<0.05; P<0.01). It indicated that allicin could promote the growth and development of immune system in layer hens.(3) With the increasing dose of allicin, the levels of Ig G, Ig M and Ig A and the HI antibody titer to newcastle disease in allicin-treated groups were significantly increased than those in CG(P<0.05; P<0.01) in serum. The results indicated that allicin could improve the humour immune function of layer hens.(4) With the increasing dose of allicin, the number of WBC, total lymphocyte count, the activity of T lymplocytes ANAE+ in allicin-treated groups were significantly higher than those in CG(P<0.05; P<0.01). The results indicated that allicin could improve the cellular immune function of layer hens.(5) With the increasing dose of allicin, the levels of C3 and C4 in allicin-treated groups were significantly higher than those in CG(P<0.05; P<0.01) in serum. The results indicated that allicin could improve the nonspecific immunity function of layer hens.(6) With the increasing dose of allicin, the levels of IL-2 in allicin-treated groups was significantly higher than those in CG(P<0.05; P<0.01), while the levels of TNF-α in allicin-treated groups was lower than those in CG(P<0.05; P<0.01). The results indicated that allicin could regulate the cytokine secretion and improve the immunity function of layer hens.(7) With the increasing dose of allicin, the erythrocyte C3 b RR ratio in allicin-treated groups was significantly higher than those in CG(P<0.05; P<0.01), while the erythrocyte ICR ratio in allicin-treated groups was significantly lower than that those in CG(P<0.05; P<0.01).The results indicated that allicin could improve the immune function of erythrocyte in layer hens.(8) With the increasing dose of allicin, the average daily body weight gain in allicin-treated groups was significantly higher than those in CG(P<0.05; P<0.01), while the feed/gain ratio in allicin-treated groups was significantly lower than those in CG(P<0.05; P<0.01). It indicated that allicin could promote the growth and development of layer hens.(9) Layer hens were stopped feeding allicin and normal raised to 200 days. With the increasing dose of allicin, the rate of producing eggs in allicin-treated groups was significantly increased than those in CG(P<0.05; P<0.01), while the feed/egg ratio and abnormal egg rate in allicin-treated groups were significantly decreased in allicin-treated groups than those in CG(P<0.05; P<0.01). It indicated that allicin could improve the growth performance of layer hens.