低鱼粉饲料对克氏原螯虾生长性能、肝肠健康及肌肉品质的影响

LOW FISH MEAL DIET ON GROWTH PERFORMANCE, HEPATOPANCREAS-INTESTINAL HEALTH, AND MUSCLE QUALITY OF RED SWAMP CRAYFISH (PROCAMBARUS CLARKII)

  • 摘要: 为探究低鱼粉饲料对克氏原螯虾存活、生长、肌肉品质及健康状况的影响, 设计了鱼粉含量为10%的高鱼粉饲料作为对照组, 鱼粉含量为2%的低鱼粉饲料(豆粕和菜粕1﹕1代替鱼粉)作为试验组, 以初始体重为(3.90±0.01) g的克氏原螯虾幼虾为实验对象, 在室内循环水养殖系统中开展了8周的养殖实验。研究结果表明, 低鱼粉饲料对克氏原螯虾的存活率、生长指标(包括增重率、特定生长率、肠指数、肝胰腺指数、性腺指数、肥满度)、表观消化率、消化酶活性、抗氧化能力、非特异免疫力均没有造成显著的负面影响; 对肌肉的基本营养成分和氨基酸组成也没有显著影响。与高鱼粉饲料相比, 低鱼粉(2%)饲料显著提高了克氏原螯虾的出肉率(P<0.05), 增加了肌肉油酸、亚油酸、α-亚麻酸、二十碳二烯酸、单不饱和脂肪酸和n-6多不饱和脂肪酸含量(P<0.05), 降低了肝胰腺的镉含量(P<0.05), 因而改善了虾的营养品质。此外, 低鱼粉饲料会引起肝胰腺和肠道组织形态发生一定程度的改变, 导致肠道菌群中普通拟杆菌的相对丰度显著降低、铁还原菌的相对丰度显著增加(P<0.05), 表明饲料中鱼粉含量过低可能不利于克氏原螯虾的肝肠健康。

     

    Abstract: In order to reduce feed costs, commercial diets for Procambarus clarkii mostly use high-level plant protein to replace fish meal, resulting in diets containing less than 5% fish meal. This study evaluated the effects of low fish meal diets on the survival, growth, muscle quality, and health of P. clarkii by comparing a control diet with 10% fish meal to an experimental diet with 2% fish meal (replacing fish meal with a 1﹕1 soybean meal–rapeseed meal mixture). P. clarkii with an initial weight of (3.90±0.01) g were used as the experimental subjects, and an 8-week aquaculture experiment was conducted in an indoor circulating water aquaculture system. The results showed that low fish meal diet did not significantly effect the survival rate, growth indicators (including weight gain rate, specific growth rate, intestine-somatic index, hepatopancreatic index, gonadosomatic index, and condition factor), apparent digestibility, digestive enzyme activity, antioxidant capacity, and non-specific immunity of P. clarkii. There is no significant impact on the basic nutritional components or amino acid composition of muscles. Compared with high fish meal feed, low fish meal (2%) diet significantly increased meat yield (P<0.05), increased the muscle content of oleic acid, linoleic acid, alpha linolenic acid, eicosaenoic acid, monounsaturated fatty acids, and n-6 polyunsaturated fatty acids (P<0.05), and reduced cadmium content in the hepatopancreas (P<0.05), thus improving the nutritional quality of crayfish. In addition, low fish meal diet induced morphological changes in hepatopancreas and intestinal tissues, significantly decreasing the relative abundance of Bacteroides vulgatus and increasing iron-reducing bacteria in the intestinal microbiota (P<0.05). Although these changes did not have a negative impact on the survival, growth, digestion, antioxidant levels, or non-specific immunity, they also indicate that low fish meal content in feed may be detrimental to the hepatopancreas and intestinal health of P. clarkii.

     

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