Study On Appropriate Level Of Arginine In A Diet Of Caged Jinding Laying Ducks Aged From5～10Weeks

The experiment was conducted to study the effects of different arginine levels on growth performance, immune function and biochemical indexes of caged Jinding laying ducks aged from5～10weeks. And aimed to discuss the most appropriate dietary arginine level by quadratic regression analysis of related sensitive indexes.A total of180healthy Jinding Ducks of5-weeks-old with an average weight (594.47±2.61)g, respecticely and analysised by variance, no obvious difference(P>0.05), who were randomly divided into5treatments with6replicates, and each replicate comprised6ducks. Ducks in control group (group Ⅰ) were fed with corn-soybean basal diet which included0.93%arginine, and others experimental groups (groups Ⅱ～Ⅴ) were fed the basal diet contend1.05%,1.17%,1.29%and1.41%, respectively, which add in the feed in the form of L-arginine hydrochloride. Experimental period was5weeks. In the experiment, ducks were weighted at the beginning, then their weight and surplus feed were weighted every two weeks to calculate daily gain, daily intake feed and feed gain ratio. At the end of the feeding trial,6ducks with weight close were randomly selected in each treatment to taken blood from wing vein, and randomly killed to take out the liver, spleen, bursa and fabricius for mensuration.The results of growth performance showed that diet with different arginine levels could increase the average daily gain and feed intake (P<0.05). The result of ratio of feed to gain showed different level of arginine had a significantly decreased compared with control group (P<0.05). And the optimal arginine suitable level estimated by the correlation of average daily gain, daily feed intake and arginine was1.20%and1.19%.The results of immune function showed there were no significant difference among spleen index (P>0.05), thymus index was raised diversely with1.05%～1.17%arginine level, and1.05%arginine level could increase bursa of fabricius index significantly well (P<0.05). The result of serum immunoglobulin showed there were no significant influence on the serum IgG and IgA (P>0.05),1.17%～1.29%level of arginine had significant effect on serum IgM compared with control group (P<0.05). Serum TP and ALB level showed a significant differences with contend of arginine in diet (P<0.05), serum IL-2was not influenced by different levels of arginine (P>0.05). The optimal arginine suitable level estimated by the correlation of serum IgM and arginine was1.21%.It had significant influence on the serum GLU, BUN, TG and CHOL (P<0.05). The optimal arginine suitable level estimated by the correlation of serum GLU and arginine was1.22%.The results of antioxidant index in liver and serum showed that, it had significant effect on the activities of T-AOC, T-SOD and GSH-Px in serum and liver total antioxidant capacity (P<0.05), but there was no significant difference in activities of GSH-Px in liver (P>0.05). Compared with the control group, it is decreased in the antioxidant index of MDA (P<0.05), and optimal arginine suitable level estimated by the correlation of T-AOC, MDA in liver and T-SOD in serum and liver with arginine was1.19%,1.20%,1.17%and1.18%.The results of serum GH and Ins index showed there were on significant influence on the GH and Ins (P>0.05).According to all the indexes, diet with a suitable supplemental level of arginine could enhance the growth performance, immune function and antioxidant function of caged growing laying ducks, and the optimal arginine suitable level estimated by quadratic regression model analysis was1.17%～1.22%.