配合饲料和冰鲜鱼对大口黑鲈肌肉中氨基酸、脂肪酸的组成和含量以及血清生化指标的影响

Effects of formulated feed and frozen fresh fish on the composition and content of amino acids and fatty acids and serum biochemical indices in the muscle of Micropterus salmoides

为缓解因大量投喂冰鲜鱼造成的大口黑鲈养殖水体污染、病害频发和生产效益降低等问题,加快推进优质配合饲料的开发,开展投喂配合饲料和冰鲜鱼对大口黑鲈营养价值和健康状况影响的研究至关重要。为此,本研究将360尾大口黑鲈分为3个试验组,分别投喂配合饲料、冰鲜鱼和混合饲料(配合饲料和冰鲜鱼的质量各占饲料总质量的50%),在饲喂90 d后对3组大口黑鲈肌肉中矿物元素含量、氨基酸的组成和含量、脂肪酸的组成和含量以及血清生化指标进行分析。结果表明,配合饲料组大口黑鲈肌肉中的Na、Ca、Zn含量显著高于冰鲜鱼组(P<0.05)。与配合饲料组和混合饲料组相比,冰鲜鱼组大口黑鲈肌肉中必需氨基酸总量占氨基酸总量的百分比以及必需氨基酸总量占非必需氨基酸总量的百分比更高。冰鲜鱼组大口黑鲈肌肉中各必需氨基酸的氨基酸评分和化学评分以及必需氨基酸指数均高于配合饲料组。配合饲料组大口黑鲈肌肉中饱和脂肪酸总量显著高于混合饲料组和冰鲜鱼组(P<0.05),但冰鲜鱼组的多不饱和脂肪酸(PUFA)总量、二十碳五烯酸含量和二十二碳六烯酸含量显著高于配合饲料组(P<0.05);与配合饲料组相比,冰鲜鱼组的n-6 PUFA含量更低,n-3 PUFA含量更高(P<0.05),并且脂肪酸品质更优。冰鲜鱼组和混合饲料组血清总蛋白质含量和碱性磷酸酶活性显著高于配合饲料组(P<0.05)。此外,冰鲜鱼组大口黑鲈血清中葡萄糖含量和谷草转氨酶活性最低(P<0.05)。因此,在本研究条件下,配合饲料影响大口黑鲈肌肉的营养价值和肝脏健康,建议参考冰鲜鱼的营养组成,进一步优化配合饲料配方。

Extensively feeding with the frozen fresh fish can contaminate the aquaculture water with nutrients and pathogens and induce disease outbreaks,ultimately reducing production efficiency of Micropterus salmoides.In order to mitigate the problems caused by extensively feeding with frozen fresh fish and boost the development of high-quality formulated feed,it is vital to evaluate the nutritional value and health status of Micropterus salmoides fed with formulated feed and frozen fresh fish.Therefore,in this study,360 healthy Micropterus salmoides were divided into three experimental groups and fed with formulated feed,frozen fresh fish and mixed feed(the weight of formulated feed and frozen fresh fish accounted for 50%of the total weight of feed,respectively).The mineral element content,the composition and content of amino acids,the composition and content of fatty acids and serum biochemical indices of Micropterus salmoides in the three groups were evaluated after feeding for 90 days.The results showed that the contents of sodium(Na),calcium(Ca)and zinc(Zn)in the muscle of Micropterus salmoides fed with formulated feed were significantly higher than those in the frozen fresh fish group(P<0.05).Compared with formulated feed and mixed feed groups,the percentage of essential amino acids to total amino acids,and percentage of essential amino acid to non-essential amino acid in the muscle of Micropterus salmoides in the frozen fresh fish group were higher.Meanwhile,the amino acid score and chemical score of each essential amino acid,and essential amino acid index in the frozen fresh fish group were higher than those in formulated feed group.The total content of saturated fatty acids in the muscle of largemouth bass in the formulated feed group was significantly higher than that in the mixed feed group and the frozen fresh fish group(P<0.05),but the total content of polyunsaturated fatty acids(PUFA),the contents of eicosapentaenoic acid and docosahexaenoic acid in the frozen fresh fish group were significantly higher than those in the formulated feed group(P<0.05).Compared with the formulated feed group,the n-6 PUFA content of the frozen fresh fish group was lower,the n-3 PUFA content was higher(P<0.05),and the fatty acid quality was better.The serum total protein content and alkaline phosphatase activity in the frozen fresh fish and mixed feed groups were significantly higher than those in the formulated feed group(P<0.05).The lowest glucose content and aspartate aminotransferase activity were observed in the frozen fresh fish group(P<0.05).Therefore,under the conditions of this study,formulated feed affected the nutritional value of muscle and liver health of Micropterus salmoides,it was recommended to refer to the nutritional composition of fresh-frozen fish and further optimize the formulated feed.