月饱食度对草鱼幼鱼生长性能、体组成、免疫能力及水质的影响

Effects of monthly satiation degree on growth performance,body composition,immunity and water quality of juveniles grass carp

为探讨月饱食度对草鱼(Ctenopharyngodon idellus)幼鱼的摄食、生长、免疫能力和养殖水体水质的影响,选取初始体重(18.10±0.09)g的草鱼幼鱼为试验对象,试验期为60 d。设计4个月饱食度,分别为月饱食量的70%、80%、90%和100%。结果表明,①试验鱼的增重率和特定生长率与月饱食度呈显著性正相关,月饱食度为100%的处理组表现出最佳的特定生长率(2.02%/d),但与月饱食度90%的处理组之间无显著差异(P>0.05);试验鱼的饲料系数与月饱食度呈显著性负相关,月饱食度为90%的处理组饲料系数最低(1.16±0.04),而月饱食度为70%的处理组饲料系数最高(1.43±0.07)。②不同月饱食度对试验鱼的存活率和形态学指标有一定的影响,其中月饱食度为100%的处理组存活率最低,但其肝体比和肥满度最高。③不同月饱食度对试验鱼肌肉营养组成成分无显著影响(P>0.05),而随着月饱食度的增加,全鱼粗脂肪含量越高(P<0.05)。④养殖水体氨氮、硝态氮和磷酸盐含量与试验鱼的月饱食呈显著性正相关(P<0.05),但养殖水体的亚硝态氮和试验鱼的血清抗氧化指标不受月饱食度变化的影响而显著性变化(P>0.05)。

In order to explore the effects of monthly satiation degree on the feeding,growth,immunity of juvenile grass carp(Cteno⁃pharyngodon idellus)and the water quality index of farmed aquatic fish ponds,juvenile grass carp with body weight of(18.10±0.09)g was selected as the test subjects for a period of 60 days.The juveniles were fed at four levels of 70%,80%,90%and 100%of month⁃ly satiation degree.The results showed that:①The weight gain rate and specific growth rate of the test fish were significantly positive⁃ly correlated with the monthly satiety,and the treatment group with monthly satiation degree of 100%showed the best specific growth rate(2.02%/d),but had no obvious difference compared with the treatment group with monthly satiation degree of 90%(P>0.05);the feed coefficient of the test fish was significantly negatively correlated with the monthly satiety,the test fish with monthly satiation de⁃gree of 90%had the lowest feed coefficient(1.16±0.04),while the test fish with monthly satiation degree of 70%had the highest feed coefficient(1.43±0.07).②Different monthly satiation degrees had a certain impact on the survival rate and morphological indicators of the test fish,among which the test fish with monthly satiation degree of 100%had the lowest survival rate,but their hepotasomatic index and condition factor were the highest.③The difference in the muscle nutrient composition of the test fish under different month⁃ly satiety levels was not significant(P>0.05),while the crude fat content in the whole fish nutrient content was significantly positively correlated with the monthly satiation degree(P<0.05).④During the test period,the contents of ammonia nitrogen,nitrate nitrogen and phosphate in the cultured water bodies increased significantly with the increase of monthly satiety(P<0.05),but the monthly sati⁃ety had no significant effect on the nitrogen nitrite nitrogen in the cultured waters and the serum antioxidant index of the test fish(P>0.05).