Fisheries and Aquaculture Program, Department of Zoology, Quaid-I-Azam University, Islamabad, 45320, Pakistan.
Department of Biology, East Carolina University, Greenville, NC, 27858-4353, USA.
Fish Physiol Biochem. 2024 Aug;50(4):1375-1389. doi: 10.1007/s10695-024-01344-3. Epub 2024 Apr 18.
Formulation and preparation of larval feed according to the requirement of Indian major carp is a prerequisite for improving the survival (%) and growth during early developmental stages. A feeding trial of 50 days in a replicate of five was conducted to determine the optimal inclusion levels of fish oil (lipid) in the larval diet of Labeo rohita. Four isonitrogenous (50% CP) nanoparticulate diets with four lipid inclusion levels, L5 (5%), L7 (7%), L9 (9%), and L11 (11%) were prepared and fed to four groups of rohu (Labeo rohita) larvae. At the end of feeding trial, survival (%), growth performance, digestive enzyme activity, gut morphology, and expression of growth and feed intake genes were evaluated. All pairwise comparisons among groups indicated higher growth performance (weight gain, specific growth rate, and daily weight gain), survival (%), and IGF-1 gene expression of the L9 group followed by the L7 while the L11 showed poor performance even less than L5. All studied intestinal enzymes except amylase showed a similar trend. Amylase showed comparable results among L7, L9, and L5, while L11 showed the lowest value. The intestinal villi length also showed higher values in L9 followed by L7, and lowest in the L11 group. Feed intake regulating genes, leptin showed lipid inclusion level upregulation, while ghrelin showed the highest expression in the L9 group. Based on growth performance, gut morphology, intestinal enzyme activity, and gene expression analysis, 9% dietary lipid could be recommended to ensure the optimum growth and survival of L. rohita larvae.
根据印度主要鲤鱼的要求制定和制备幼虫饲料是提高早期发育阶段存活率（%）和生长的前提。进行了为期 50 天的重复喂养试验，以确定饲料中鱼油（脂质）在罗非鱼幼虫饮食中的最佳含量。制备了四种等氮（50%CP）纳米颗粒饲料，包含四种脂质含量水平，L5（5%）、L7（7%）、L9（9%）和 L11（11%），并分别喂养到四组罗非鱼（Labeo rohita）幼虫。在喂养试验结束时，评估了存活率（%）、生长性能、消化酶活性、肠道形态和生长和饲料摄入基因的表达。所有组间的两两比较表明，L9 组的生长性能（体重增加、特定生长率和日增重）、存活率（%）和 IGF-1 基因表达更高，其次是 L7 组，而 L11 组表现不佳，甚至低于 L5 组。除了淀粉酶外，所有研究的肠道酶都表现出类似的趋势。淀粉酶在 L7、L9 和 L5 之间表现出相似的结果，而 L11 表现出最低的值。肠道绒毛长度在 L9 组中也表现出较高的值，其次是 L7 组，而在 L11 组中则最低。摄食调节基因，瘦素表现出脂质含量的上调，而 ghrelin 在 L9 组中的表达最高。基于生长性能、肠道形态、肠道酶活性和基因表达分析，建议将 9%的膳食脂质添加到饲料中，以确保罗非鱼幼虫的最佳生长和存活率。
