Effects Of Inulin On Growth Performance, Immune Organs Indices And Antioxidantion Of Broilers

The objective of this study was to assess the effects of inulin on growth performance, immune function and antioxidant function of broilers, which applied theoretical basis for the application of inulin in animal feed. Two hundred and eighty day-old Cobb500male broilers were randomly divided into four groups with seven replicates per group and10birds each replicate. Group Ⅰ was fed corn-soybeans basal diet as control. Group Ⅱ, Ⅲ, Ⅳ were fed0.5%,1.0%,1.5%inulin respectively. Feed residuals and birds were weighed weekly to determine the feed intake, growth rate and feed conversion ratio (FCR). On d21and d42, two birds from each replicate were randomly picked out and killed, samples were collected for further assess. Immune organ index, immunoglobulin, cytokine and antioxidant indexes were determined. The results showed that:1. Compared with the control group, Group Ⅲ, Ⅳ significantly improved livability of broilers aged1to42days(p<0.05). In addition that Ⅲ group had significant effect on feed intake of broilers aged22to42days(p<0.05), there was no significant difference in other groups(p>0.05). But the increasing trend of body weight gain and feed intake as well as the decreasing trend of feed conversion ratio had appeared.2. Compared with the control group, Group Ⅲ, Ⅳ significantly improved spleen, Bursa F of broilers aged21days(p<0.05). On d42, Group Ⅲ, Ⅳ significantly improved the thymus and spleen index (p<0.05). Bursa F index of broilers in inulin supplemented groups were not significantly changed compared with control group(p>0.05), but that in Group Ⅱ, Ⅲ, Ⅳ increased2.29%,5.14%,4.57%respectively than the control group, which indicated that inulin can promote immune organ development.3. On d21, IgG concentration in serum was increased in Group Ⅱ, Ⅲ,Ⅳ(p<0.05), but the concentrations of IgM and IgA were not changed significantly among groups. On d42, the content of IgA, IgM and IgG in serum were increased in Group Ⅲ, Ⅳ compared with the control group (p<0.05).4. On d21, the serum concentrations of IL-2and IL-10in Group Ⅲ, Ⅳ were significantly increased compared with control group(p<0.05). The content of IL-6in serum was also increased in Group Ⅱ. On d42, Group Ⅲ, Ⅳ significantly improved IL-2, IL-6, IL-10and IFN-γ of serum compared with control group(p<0.05).5. We tested the level of T-SOD, GSH-Px, MDA in both liver and serum of broilers from d1to d42in this experiment. The results showed that Group Ⅲ,Ⅳ had significant difference on T-SOD, GSH-Px and MDA in liver of broilers from d1to d42. From d1to d42, Group Ⅲ, Ⅳ significantly improved T-SOD, GSH-Px of serum compared with control group (p <0.05). The content of MDA in serum was also significantly decreased in Group Ⅱ on d42. It showed that the right amount of inulin diet can improve the antioxidant function of broilers, and with the extension of breeding period, the results showed better.Overall, the supplementation of inulin in dietary had minor effect on growth performance of broilers, but could significantly enhance livability, the body immunity and antioxidant function of broilers. The effect of later period was obviously better than that of early stage. The antagonism effect caused by excessive intake of inulin was not observed in this experiment and1.0%and1.5%inulin supplementation showed the best effect. But1.0%was appropriate in consideration of feed cost.