昆明裂腹鱼幼鱼烟酸需求量研究

摘要

为探究昆明裂腹鱼幼鱼对烟酸的需求量，选用平均体质量为（25．97±9．29） g的昆明裂腹鱼幼鱼，随机分为6组，每组10尾，其饲料中烟酸含量分别为15．5、28．671、38．516、68．685、81．608、99．568 mg/kg ，饲养时间为10周，日投喂量为体质量的2％～5％。试验结果表明，随饲料中烟酸含量的增加，特异生长率和质量增加率先升后降，烟酸水平为38．516 mg/kg时，试验鱼的质量增加率和特异生长率均达最大，为144．788％、1．24336％/d。28．617 mg/kg组和38．516 mg/kg组试验鱼肥满度最大，显著高于对照组（P＜0．05），其他组与对照组差异不显著（P＞0．05）。肝胰脏指数和肠道指数在28．617 mg/kg组和38．516 mg/kg组最大，显著高于对照组（P＜0．05）；其他组中肝胰脏指数显著小于对照组（ P＞0．05）。各组间的存活率均为100％，而添加烟酸的饲料对试验鱼血红蛋白含量无明显影响，与对照组差异不显著（P＞0．05），对照组的烟酸水平已满足试验鱼维持正常的血红蛋白含量。以特异生长率为评估指标，应用折线法得出昆明裂腹鱼幼鱼获得最大生长时烟酸需求量为36．83 mg/kg。%Juvenile Kunming schizothoracin Schizothorax graham with initial body weight of (25 .97 ± 9 .29) g were randomly divided into 6 groups at a rate of 10 fish per group and fed diets containing niacin of 15 .5(control group) ,28 .671 ,38 .516 ,68 .685 ,81 .608 ,and 99 .568 mg/kg at a feeding rate of 2% -5%for 10 weeks .Condition factor ,weight gain rate ,specific growth rate ,and hepatopancreas index ,and intestinal index were measured to evaluate the optimal dietary requirement of niacin .The results showed that the specific growth rate and the weight gain rate were found to be first increased and then decreased with the increase in dietary nicotinic acid content , the maximum (144 .788% in weight gain , and 1 .24336% /d in specific growth rate ) in 38 .516 mg/kg group . The maximal condition factors and hepatopancreas indexes were observed in the 28 .617 and 38 .516 mg/kg groups ,significantly higher than those in the control group (P<0 .05) .In other groups ,however ,the hepatopancreas indexes were found significantly lower than that in the control group (P<0 .05) .There was survival rate of 100% in each group ,and the hemoglobin in each groups were no significant difference (P>0 .05) ,which is attributed to the fact that the nicotinic acid content in the control diet meets the normal demand .In this experiment ,the optimal dietary nicotinic acid level of juvenile Kunming schizothoracin is of 36 .83 mg/kg based on the specific grow th rate .