Effect Of Oil Origanum On Performance And Immunity Of Laying Hens

This study was designed to investigate the effects on performance and immunity of differentlevels of origanum oil added in laying hens.300Hy-Line layers with the age of30weeks were selected and randomly divided into5groups (6replicates per treatment,10hens pre replicate) in the study. The control group was fedon basal diets. A, B and C group was respectively fed on diets with50,100and150mg/kg oiloriganum. Antibiotics group was fed on diets with100mg/kg of10%colistin sulfate. Thepreliminary trial period was7days, and the experimental period lasted for60days.The results were showed as follows:1) There was no significant difference among everygroup in average daily feed intake (P>0.05). The laying rate of group A and B were significantlyincreased (P<0.05) and the feed to egg ratio were significantly decreased (P<0.05) comparedwith control. The average egg weight of group A and B were significantly increased comparedwith antibiotics group (P<0.05).2) The population of WBC and LYM in blood of group A hadthe tendency of increase (P>0.05). The levels of serum IgG in A, B and C group weresignificantly higher than control (P<0.05) and new castle antibody titer of A group wassignificantly increased (P<0.05) compared with control at the30th day and the60th day in theexperiment. The levels of serum IgM, IgA, complement C3and C4in A group showed increasingtrend (P>0.05).3) There was no significant difference on spleen index and CD4+%among everygroup (P>0.05). However, compared with control group, the levels of CD8+%in group A wassignificantly decreased (P<0.05) and the levels of CD4+/CD8+was significantly increased(P<0.05). Moreover, the levels of mRNA of IL-2in spleen of group A were significantlyincreased than control and antibiotics groups (P<0.05), and IL-4in spleen of group A weresignificantly increased than antibiotics group (P<0.05). The expression of IFN-γ and IL-10mRNA in spleen of group A were significant decrease than control, but higher than B, C andantibiotics group.It is concluded that oil origanum can improve the performance and immune function oflaying hens, and the suitable supplemental dosage of oil origanum is50mg/kg.