| Two experiments were conducted to study the effect of methionine on digestion and immune function of juvenile Jian Carp (Cyprinus carpio Var. Jian). In trial, 576 juvenile Jian carps(initial weight 12.34±0.02g) were randomly allocated to 4 groups, feeding control diet or control diet containing uncoated or control diet containing two coated methionine respectively for 65 d. In trial II, 864 juvenile Jian carps(initial weightl2.34± 0.02g) were randomly allocated to 6 groups feeding semi-purified diets containing methionine 0.39, 0.70, 1.00, 1.30, 1.60, 1.90% respectively for 65 d. After 65d, a challengetrial was conducted by injection of Aeromonas Hydrophila (AH) for 17 day.In trial I , weight gain, feed intake, feed conversion efficiency, protein retention ration, lipid retention ratio increased significantly as diet added with coated or uncoated methionine (P<0.05). Weight gain, feed conversion efficiency, protein retention ratio, lipid retention ratio, ash retention ratio increased significantly as diet added with coated methionine 1 and methionine 2 (P<0.05). Plasma albumin content, glutathione reductase, ammonia content, tissue GOT activity, and hepatopancreas weight, intestine weight, intestine length, intestine and hepatopancreas protein lipase activity, trypsin activity and chymotrypsin activity, intestinal folds height, intestinal alkaline phosphatase and Na+,K+-ATPase activity increased significantly as diet added with coated or uncoated methionine (P<0.05). Morever, ammonia content in plasma, intestinal weight, hepatopancrease weight, hepatopancrease protein, hepatopancrease trypsin activity, intestinal alkaline phosphatase activity increased significantly as diet added with coated methioninel (P<0.05). Albumin content in plasma, intestinal weight, intestinal length and protein content, hepatopancrease weight and protein content, hepatopancreas and intestinal lipase activity, trypsin activity and chymotrypsin activity, intestinal alkaline phosphatase and Na+,K+ATPase activity as diet added with coated methionine2 (P<0.05). Kidney weight, spleen weight, erythrocyte and leucocyte count and survival rate, phago-ratio of leucocyte, acid phosphatase activity, lysozyme activity, complement component C3, agglutinin level in plasma and antibody titers after vaccination against Aeromonas hydrophila (AH) increased significantly as diet added with coated or uncoated methionine (P<0.05). Hind kidney weight and spleen weight increased significantly as diet added with coated methioninel (P<0.05). Kidney weight, spleen weight, acid phosphatase activity increased... |
