Abstract:
Inappropriate substitution of dietary fishmeal (FM) can adversely affect the growth, health, and metabolism of carnivorous fish species. To effectively reduce the amount of dietary FM in carnivorous largemouth bass (Micropterus salmoides), a terrestrial compound protein (Cpro) with chicken meal, bone meal, and black soldier fly protein was used to formulate four isoproteic (52%) and isolipidic (12%) diets, namely T1 (36% FM), T2 (30% FM), T3 (24% FM), and T4 (18% FM), for feeding juveniles (initial weight: ~12 g) for 81 days. Results indicated that the growth performance, feed efficiency, and morphological indicators, as well as muscle texture and edible quality of fish, did not differ significantly among the four groups. However, the muscle protein contents and ATP/AMP ratio of fish in the T4 group were significantly increased in comparison with those of fish in the T1 group, while the opposite was true for muscle glycogen. Compared with the T1 group, high serum total amino acid and MDA contents, as well as low AST activities, were observed in the T3 and T4 groups, and relatively high intestinal trypsin and lipase activities were found in the T2-T4 groups. The transcripts of intestinal proinflammatory cytokines (il-1β, il-6, and tnf-α) were downregulated in the T2-T4 groups compared with T1 group, while the expression of anti-inflammatory cytokines (il-10) and tight junction (zo-1 and occludin) showed the reverse trend. The mRNA expression of positive regulators related to protein synthesis (sirt1, pgc1-α, pi3k, and akt) were significantly upregulated in the muscle of fish fed diets T3 and T4, while their negative regulators (4e-bp1) mRNA levels were downregulated. The results indicate that the dietary FM of largemouth bass could be effectively reduced to at least 18% by the Cpro, which is beneficial to health, digestion, and protein synthesis for maintaining accelerated growth.
摘要:
饮食鱼粉(FM)的不适当替代会对生长产生不利影响,健康,和食肉鱼类的新陈代谢。为了有效减少食肉大嘴鲈鱼(Micropterussalmoides)的饮食FM量,含鸡肉的陆生复合蛋白(Cpro),骨餐,黑兵蝇蛋白被用来配制四种异变蛋白(52%)和异变蛋白(12%)的饮食,即T1(36%FM),T2(30%FM),T3(24%FM),和T4(18%FM),用于喂养幼鱼(初始体重:〜12g)81天。结果表明,生长性能,饲料效率,和形态学指标,以及鱼的肌肉质地和食用品质,四组之间没有显着差异。然而,与T1组相比,T4组鱼的肌肉蛋白含量和ATP/AMP比值显着增加,而肌糖原则相反。与T1组相比,血清总氨基酸和MDA含量高,以及低AST活动,在T3和T4组中观察到,在T2-T4组中发现相对较高的肠胰蛋白酶和脂肪酶活性。肠道促炎细胞因子的转录本(il-1β,与T1组相比,T2-T4组的IL-6和tnf-α)下调,而抗炎细胞因子(il-10)和紧密连接(zo-1和occludin)的表达呈相反趋势。与蛋白质合成相关的正调节因子的mRNA表达(sirt1,pgc1-α,pi3k,和akt)在饲喂饮食T3和T4的鱼的肌肉中显着上调,而其负调节因子(4e-bp1)mRNA水平下调。结果表明,Cpro可以有效地将大口鲈鱼的饮食FM降低到至少18%,这对健康有益,消化,和蛋白质合成以保持加速生长。