| The experiment was conducted to study the effects of calcium (Ca),vitamin D (VD) and their interaction on immune and antioxidant functions in broilers.Using 2×2 completely randomized experimental design, Ca had two levels, which were suitable Ca (0.90%) and high Ca (1.15%).And vitamin D also had two levels, which were suitable vitamin D (750 IU / kg) and high vitamin D (5 000 IU / kg).One hundred and forty-four 4-weeks-old Arbor Acres (AA) broilers with the close body weight were divided into 4 treatments with 6 replicates in each treatment and 8 broilers in each replicate.Suitable Ca suitable VD treatment was groupâ… , suitable Ca high VD treatment was groupâ…¡; high Ca suitable VD treatment was groupâ…¢and high Ca high VD treatment was groupâ…£.The results: High level VD increased immune organ index , and the effect on the thymus and spleen index were significant(P<0.05).High level Ca significantly reduced bursa index(P<0.05). The interaction of VD and Ca significantly influenced on spleen index(P<0.05).5000 IU / kg VD increased IgA, IgM, IgG, ALB content and lowered A / G ratio(P>0.05), and significantly increased GLO content(P<0.05). High level Ca decreased immune globulin, ALB, GLO, and A/G , and the effect on the IgG was significant(P<0.05).The interaction of VD and Ca had significant effect on GLO(P<0.01).High level VD decreased IL-2(P>0.05).High level Ca significantly increased IL-2(P<0.05). The interaction of VD and Ca had significant effect on IL-2(P<0.01).When adding high level VD, GH, T4 and T3 were increased(P>0.05), and Cort was decreased(P>0.05). Effect of Ca on serum hormones were not significant(P>0.05), but increasing Ca level had opposite effect with increasing VD. The interaction of VD and Ca had significant effect on GH,T4å'ŒT3(P<0.01).When adding high level VD, the activities of CAT, T-SOD, GSH-PX and T-AOC were increased and MDA content was decreased, and the effect on serum GSH-PX was significant(P<0.05).High level Ca could reduce the activities of T-SOD, GSH-PX andT-AOC, and had significant effect on the liver(P<0.05),but had no significant effect on MDA and CAT(P>0.05). The interaction of Ca and VD had significant effect on T-SOD, GSH-PX and MDA(P<0.05).When adding high level VD, serum Ca content was significantly increased(P<0.05), but VD had no significant effect on AKP(P>0.05).Ca content and AKP activity in serum were increased when adding high level Ca (P>0.05).The interaction of Ca and VD had significant effect on Ca content(P<0.05).VD had no significant effect on blood TP and BUN(P>0.05). When adding high level VD, TP was increased, while BUN tended to be decreased somewhat.Ca had no significant effect on blood TP and BUN(P>0.05), and increasing Ca level had opposite effect with increasing VD.The interaction of VD and Ca significantly effected on blood TP(P<0.05).High level VD decreased CHO, TG, and Glu(P>0.05).CHO and TG were decreased with adding high level Ca (P>0.05), while Glu was increased(P>0.05).The interaction of VD and Ca had no significant effect on Glu(P>0.05), but had significant effect on CHO and TG(P<0.05).All the above indicators showed that vitamin D could promote calcium absorption.When adding appropriate dosage of calcium, immune function of broilers could be improved to some extent; antioxidant function was significantly increased and blood glucose and blood lipid were reduced by adding high level vitamin D.Therefore, in practice, adding the basal level calcium and more vitamin D than the basal need at the same time had important effects on improving healthy aquaculture of broilers... |
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