| The trial was conducted to study the the effects of glutamine on growth performance and intestinal development and function of juvenile Jian carp(cyprinus carpio Var.Jian).ln trial, 960 juvenile Jian carps with initial weight 7.78±0.02g were averagely allocated to 6 treatments with 3 replications , feeding diets with added glutamine 0, 0.4, 0.8, 1.2, 1.6, and 2.0% respectively for 80 days.The results showed as follows: weight gain, feed intake, feed conversion efficiency, hepatopancreas weight, intestine weight, intestine length, height of proximal and distal intestinal folds, protease,lipase,alkaline phosphatase,Na~+,K~+-ATPase, γ -glutamyl transpeptidase,phago-rate of leukocyte, glutathione levels of serum,intestine and hepatopancreas, survival rate and serum antibody level at 17d after vaccination against Aeromonas hydrophilaand were significantly affected by the dietary Gln level. There was a significant correlation between feed intake and feed intake / weight gain with Gln levels (r1 =+0.948, P < 0.01; r2=-0.9530, < 0.01). The significant correlation also existed between weight gain and retention ration of protein and fat, intestine weight, intestine length,activity of protease, lipase, alkaline phosphatase,Na~+,K~+-ATPase, γ -glutamyl transpeptidase(r1=+ 0.9950, P < 0.01; r2=+0.9930, P < 0.01; r3=+0.9920, P < 0.01; r4=+0.9960, P<0.01; r5=+0.9900, P<0.01; r6=+0.9900, P<0.01; r7=+0.9910, P<0.01; r8=+0.9080, P<0.05; r9=+0.9900, P < 0.01) .The significant correlation existed between feed conversion efficiency and intestine weight, intestine length,activity of protease, lipase,alkaline phosphatase,Na~+,K~+-ATPase, γ -glutamyl transpeptidase(r1=+0.9940, P < 0.01; r2=+0.9970, P < 0.01; r3=+0.9980, P < 0.01; r4=+0.9970, P < 0.01; r5=+0.9970, P < 0.01; r6=+0.9960, P < 0.01; r7=+0.9490, P < 0.01). There were significant correlation between blood hematocyte counts, phago-rate of leukocyte, survival rate, serum lysozyme activity and serum antibody level at 17dafter vaccination against Aeromonas hydrophila and glutamine level (r 1 =+0.9920, P < 0.01; r2=+0.9870, P<0.01; r3=+0.9770, P<0.01; r4=+0.9890, P<0.01; r5=+0.9710, P<0.01; r6=+0.9880, P<0.01) .The results of correlation analysis indicated that there were significant correlation between survival rate after vaccination against Aeromonas hydrophila and phago-rate of leukocyte, serum lysozyme activity and serum antibody level (rl =+0.9860, P<0.01; r2=+0.9720, P <0.01; r3=+0.9430, P<0.01; r4=+0.9800, P<0.01) .The path-analysis results indicated that there were significant direct effect of feed intake , feed efficiency, glutamine level on weight gain (path coefficient 0.3200 ^ 0.2608> 0.4161,decision coefficient do.i=O. 1024; do.2=O.O68O; do.3=O. 1731) ,which means the supplement of glutamine have crucial role on weight gain .Glutamine level ,activity of protease lipase, alkaline phosphatase,Na+,K+-ATPase and y -glutamyl transpeptidase have significant direct effect on retention ration of proteinCpath coefficient 0.0345>0.5676> 0.4649 ^ +0.0710) and significant direct effect of phago-rate of leukocyte and serum antibody level on survival rate (path coefficient 0.1058^ 0.690K 0.2386).In summary, added glutamine resulted in growth improvement of juvenile Jian carps through increasing feed intake and utilization. The increasing of digestible ability was due to intestinal growth, enhancement of enzyme activity accompanied by increasing dietary glutamine. Meanwhile supplementation of dietary glutamine caused resisting diseases ability of juvenile Jian carps increased by promoting head kidney and spleen growth, increasing serum, intestine, hepatopancreas glutathione content, and increasing non-specific and specific immune ability. 8-40g juvenile Jian carps appeared best growth performance, non-specific or specific immune ability as feeding the diets containing glutamine 1.2% and 1.6% respectively.
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