优化鱼类性能取决于几个因素,日粮蛋白质水平和饲养温度起着重要作用。在这项研究中,平均体重为20.00±1.26g的尼罗罗非鱼鱼种(Oreochromisniloticus)分为9组(一式三份)。每组经受不同的水温(26°C,28°C,和30°C),并接受三种日粮蛋白质水平之一(20%,25%,和30%)两个月。我们的研究结果表明,较高的温度,特别是在30°C时,增加水的电导率和总溶解盐,在饲喂25%或30%粗蛋白(CP)的鱼中尤其明显。在28°C和25%CP下观察到较低的总氨氮水平,30°C,含30%CP,和26°C与30%CP。在26°C时,鱼的肝脏生长激素受体1和胰岛素样生长因子1表达随着饮食CP百分比的升高而逐渐升高,但在30°C时下降。尽管保持高于28°C组的25%CP。当饲喂20%或25%CP时,28°C的鱼显示出最佳的最终体重和生长性能,这些组之间没有显着差异。各组肝瘦素表达无显著差异,但是,在26°C和30°C下饲喂30%CP的鱼中,肝脏脂肪酸结合蛋白的表达显着增加,而在28°C和25%CP的鱼中。在同一温度组中,饲喂30%CP的鱼表现出更高的球蛋白水平,特别是在28°C或30°C下蓬勃发展。肝粘蛋白样蛋白表达在所有组显著增加,特别是在30°C和30%CP的鱼中,与28°C和25%CP的鱼相比。在30°C和30%CP的鱼中,肝溶菌酶的表达也显着增加。超氧化物歧化酶的显著变化,过氧化氢酶,观察谷胱甘肽过氧化物酶的表达,在30°C和25%CP的鱼类中,血清超氧化物歧化酶和过氧化氢酶活性最高。总的来说,膳食蛋白质水平为25%和30%,结合28°C和30°C的温度,产生了有利的结果,特别有利于28°C和25%的蛋白质。
Optimizing fish performance depends on several factors, with dietary protein levels and rearing temperature playing important roles. In this study, Nile tilapia fingerlings (Oreochromis niloticus) weighing an average of 20.00 ± 1.26 g were divided into nine groups (in three replicates). Each group was subjected to different water temperatures (26 °C, 28 °C, and 30 °C) and received one of three dietary protein levels (20%, 25%, and 30%) for two months. Our findings indicate that higher temperatures, particularly at 30 °C, increased water electrical conductivity and total dissolved salts, especially noticeable in fish fed 25% or 30% crude protein (CP). Lower total ammonia nitrogen levels were observed at 28 °C with 25% CP, 30 °C with 30% CP, and 26 °C with 30% CP. Hepatic growth hormone receptor 1 and insulin-like growth factor 1 expression gradually rose with higher dietary CP percentages in fish at 26 °C but declined in those at 30 °C, albeit remaining higher than in the 28 °C groups with 25% CP. Fish at 28 °C showed the best final body weights and growth performance when fed 20% or 25% CP, with no significant difference between these groups. Hepatic leptin expression did not differ significantly among groups, but hepatic fatty acid binding protein expression notably increased in fish fed 30% CP at both 26 °C and 30 °C compared to those at 28 °C with 25% CP. Within the same temperature group, fish fed 30% CP exhibited higher globulin levels, particularly thriving at 28 °C or 30 °C. Hepatic mucin-like protein expression significantly increased across all groups, especially in fish at 30 °C with 30% CP compared to those at 28 °C with 25% CP. Hepatic lysozyme expression also increased notably in fish at 30 °C with 30% CP. Notable changes in superoxide dismutase, catalase, and glutathione peroxidase expression were observed, with the highest serum superoxide dismutase and catalase activities recorded in fish at 30 °C with 25% CP. Overall, dietary protein levels of 25% and 30%, combined with temperatures of 28 °C and 30 °C, yielded favorable outcomes, particularly favoring 28 °C with 25% protein.