饲料蛋白水平对台湾泥鳅幼鱼生长、饲料利用率及免疫酶活性的影响

本研究旨在评价饲料蛋白水平对台湾泥鳅(Paramisgumus dabryanus ssp)幼鱼生长性能、饲料利用率及免疫酶活性的影响。选用初始体重为(8.57±0.35)g的台湾泥鳅720尾,随机分成4组,每组设置3个重复,每个重复60尾鱼,分别投喂蛋白水平为25%、30%、35%和40%的实验饲料,养殖时间为60 d。结果显示,随着饲料蛋白水平的升高,台湾泥鳅幼鱼末重(FW)、特定生长率(SGR)和饲料效率(FER)先上升,饲料蛋白水平≥35%后,进入平台期。蛋白质效率(PER)、蛋白质沉积率(PRE)和成活率(SR)均呈先升高后降低的变化趋势。摄食率(FR)则呈逐渐降低的趋势。基于FW、SGR和FER的折线模拟结果表明,台湾泥鳅幼鱼达到最佳生长速度及饲料效率的饲料蛋白水平为34.57%~35.37%。通过二次多项式回归分析可知,台湾泥鳅幼鱼蛋白利用率最高时的饲料蛋白水平为33.61%~34.68%。随着饲料蛋白水平的升高,台湾泥鳅幼鱼超氧化物歧化酶(SOD)活性呈先升高后趋于稳定的变化趋势,过氧化氢酶(CAT)活性呈先升高后降低的变化趋势;谷丙转氨酶(GPT)和谷草转氨酶(GOT)均呈先升高后降低的变化趋势。由此得出,适宜的饲料蛋白水平可促进台湾泥鳅幼鱼的生长,提高饲料效率,增强免疫酶活性。在本实验条件下,综合考虑生长性能、饲料利用率及免疫酶活性,台湾泥鳅幼鱼饲料最适蛋白水平为34.68%~35.37%。

Effects of Dietary Protein Level on Growth Performance, Feed Efficiency, and Immuno-Enzymatic Activity of Paramisgumus dabryanus ssp

The present study aimed to investigate the effects of dietary protein level on the growth performance, feed efficiency, and immuno-enzymatic activity in Paramisgumus dabryanus ssp. Four diets were formulated with 25%, 30%, 35%, and 40% protein, respectively. In total, 720 P. dabryanus ssp with an initial body weight of (8.57±0.35) g were randomly divided into 4 groups with 3 replicates per group and 60 fish per replicate. The cultivation of P. dabryanus ssp lasted for 60 d feeding with the four diets. The results showed that the final weight (FW), specific growth rate (SGR), and feed efficiency rate (FER) of P. dabryanus ssp increased with increase in dietary protein level, and plateaued at the dietary protein level of 35%. Initially, the protein efficiency ratio (PER), protein retention (PRE), and survival rate (SR) increased, and then started to decrease. However, the feeding rate (FR) showed a gradual decrease with increasing dietary protein level. The results of broken line simulation of FW, SGR, and FER showed that the P. dabryanus ssp had the optimal growth and feed efficiency rates at a dietary protein levels between 34.57% and 35.37%. Furthermore, the quadratic polynomial regression analysis revealed that the utilization of protein by the P. dabryanus ssp reached the highest level at the dietary protein levels between 33.61% and 34.68%. The activity of superoxide dismutase (SOD) in P. dabryanus ssp increased at first and then plateaued with increasing dietary protein level. The activity of catalase (CAT) in the P. dabryanus ssp increased at first and then decreased. The activity of glutamic oxaloacetic transaminase (GOT) and glutamate pyruvic transaminase (GPT) in the P. dabryanus ssp increased at first and then decreased with increase in dietary protein levels. These results show that a suitable dietary protein level can improve the growth rate, feed efficiency, and immuno-enzymatic activity of P. dabryanus ssp. Furthermore, a comprehensive analysis of growth performance, feed efficiency, and immunity-related enzyme activity revealed that the optimal dietary lipid level for P. dabryanus ssp is 34.68%~35.37%.