大豆分离蛋白替代鱼粉对虹鳟生长性能及氮磷排泄的影响(英文)

以体重为(4.86±0.02)g的虹鳟稚鱼为实验对象,在室内循环水养殖系统中进行为期90d的生长实验。用1000 U/kg植酸酶预处理大豆分离蛋白,然后以预处理的大豆分离蛋白(Soy protein isolate,SPI)分别替代0、20%、40%、60%、80%和100%的鱼粉蛋白,配制成6种等氮(粗蛋白为44.97%)、等能(粗脂肪为13.42%)的饲料,以评估饲料中鱼粉替代量对虹鳟生长、体组成、消化率及氮磷排泄的影响。90d的养殖实验结果表明,大豆分离蛋白替代鱼粉对虹鳟生长性能和饲料利用率产生显著的影响(P<0.05)。当大豆蛋白替代水平由0增加到40%时,虹鳟的特定生长率(SGR)显著提高,随着饲料中SPI替代水平由40%增加到100%时,虹鳟的SGR显著降低(P<0.05),在S0、S20和S60试验组之间差异不显著(P>0.05)。增重率(WGR)和蛋白质效率(PER)分别在处理组之间的差异关系与特定生长率(SGR)在各组之间的变化趋势相类似;当大豆蛋白分别替代40%时,其饲料系数(FCR)显著低于其他替代组(P<0.05),当替代量超过40%后,随着替代水平的增加,FCR显著增加(P<0.05)。随着替代水平由0升高到100%,磷排泄显著降低,与之相反的是,磷沉积率显著升高。随着替代水平由0升高至40%,氮排泄逐渐降低,当替代水平由40%升高至100%,氮排泄逐渐升高,随着替代水平升高至40%,氮沉积率升高。试验证明,大豆分离蛋白替代量达到40%时,虹鳟的生长及饲料转化率达到最佳,而高比例的SPI对虹鳟的生长性能和饲料效率产生负面影响。

Abstract： A 90-day feeding trial was conducted in indoor culture system to evaluate the effects of replacing fish meal with phytase- pretreated soybean protein isolate （PP-SPI） in feeds for juvenile Rainbow trout （Oncorhynchus rnykiss）. The fish [initial body weight （4.86±0.02） g] were fed six isonitrogenous and isocaloric feeds （crude protein, 44.97%; crude lipid, 13.42%）. The diets were formulated to produce diets in which 0, 200, 400, 600, 800 and 1000 g/kg of protein from fish meal were replaced with that from PP-SPI. SPI was pretreated by phytase at the level of 1000 U/kg. The results showed that the specific growth rate （SGR） increased significantly when the PP-SPI replacement level from 0 to 40%, and there was a significant decrease for PP-SPI replacement level from 40% to 100%. Weight gain and protein efficiency ratio （PER） showed the same trend as in the SGR. The minimum value （1.10） of FCR was at 40% replacement （S40） of fish meal with PP-SPI （P〈0.05）, and there was a significant increase for PP-SPI replacement level from 40% to 100%. P excretion significantly decreased as the proportion of PP-SPI replacement in the diet increased. However, efficiency of P retention significantly increased with increasing PP-SPI level （P〈0.05）. The N excretion de- creased with increase of PP-SPI replacement level from 0% to 40%, then increased with the increase of PP-SPI replace- ment level from 40% to 100%. The N retention increased with increasing levels of PP-SPI replacement to 40%, while decreased with increasing levels of PP-SPI replacement from 40% to 100%. The results of the present study showed that 40% of fish meal could be replaced by PP-SPI in diets of juvenile rainbow trout with maximum weight gain or feed efficiency.