饲料蛋白质水平对马苏大麻哈鱼幼鱼生长指标和饲料系数的影响

Effect of feed protein level on growth and feed conversion ratio of Oncorhynchus masou masou juvenile fish

为了解在水温7.4~11.3℃的流水池养殖条件下马苏大麻哈鱼(Oncorhynchus masou masou)幼鱼饲料中不同蛋白质水平对其生长指标和饲料利用效率的影响,设计了5组蛋白质水平为40.40%、44.84%、50.16%、54.82%和59.03%的养殖试验,养殖期为150d。试验过程中进行了水质化学指标的监测,结果表明随着饲料蛋白质水平增高,总氮、氨氮、亚硝酸盐氮有升高的趋势,40.40%组与44.84%、50.16%、54.82%及59.03%组总氮具统计学意义差异;59.03%组与其余4组氨氮、亚硝酸盐氮具统计学意义差异;40.40%、44.84%、50.16%、54.82%4组间总磷、硫化物和COD无统计学意义差异,59.03%组与上述4组间总磷、硫化物和COD均具统计学意义差异。生长试验结果表明:随蛋白质水平升高,40.40%、44.84%、50.16%组间终末体质量、增重率有显著升高的趋势(P<0.05),54.82%、59.03%组间终末体质量显著降低;50.16%试验组与其余4组特定生长率具统计学意义差异。各试验组随蛋白质水平升高,饲料系数有下降的趋势,40.40%、44.84%组的饲料系数是2.02、1.98,显著高于50.16%、54.82%、59.03%试验组,饲料蛋白质含量从40.40%增加到59.03%,饲料系数有逐渐降低趋势。通过生长指标和折线模型计算马苏大麻哈鱼幼鱼饲料适宜蛋白质含量为50.78%。

To know the influence of different protein levels on the growth and feed utilization efficiency of Oncorhynchus masou masou juvenile fish feed under the condition of water temperature 7.4~11.3℃,5 experiments protein levels of 40.40%,44.84%,50.16%,54.82%and 59.03%were designed.The breeding period was 150 days.During the experiment,the chemical index of water quality was monitored.The results showed that total nitrogen,ammonia nitrogen and nitrite nitrogen had an increasing trend as protein levels in the feed increased.There were significant differences between the 40.40%group and 44.84%,50.16%,54.82%and 59.03%groups in total nitrogen.59.03%was significantly different from the other 4 groups in ammonia nitrogen and nitrite nitrogen.There were no significant differences among 40.40%,44.84%,50.16%and 54.82%in total phosphorus,sulfide and COD.There were significant differences between the 59.03%group and the above 4 groups.The growth experiment results showed that with the increase of protein levels,terminal body weights,weight gain rates of the 40.40%group,44.84%group and 50.16%group showed a significantly increased trend(P<0.05).The terminal body weight of 54.82%and 59.03%were significantly reduced.The specific growth rate of 50.16%was significantly different from those of the other 4 groups.The feed conversion ratio of each experimental group decreased with the increase of protein level,and the feed conversion of 40.40%group and 44.84%group was 2.02 and 1.98,respectively,significantly higher than that one of 50.16%,54.82%,59.03%groups.When the feed protein content increased from 40.40%to 59.03%,the feed conversion ratio gradually decreased.The suitable protein content of juvenile salmon feed was calculated by growth and?line model to be 50.78%.