脂肪酶与乳化剂联合应用对吉富罗非鱼饲料中脂肪的节约效应

The Lipid-sparing Effect of Combined Application of Lipase and Emulsifier in Diet of GIFT Strain of Nile tilapia(Oreochromis niloticus)

试验旨在研究脂肪酶与乳化剂联合应用对吉富罗非鱼饲料中脂肪的节约效应。选取体重为(40.55±0.14)g的试验鱼360尾,随机分成4组,每组3个重复。分别投喂高脂饲料(HL组,脂肪水平为8.0%)、低脂饲料(LL组,脂肪水平为7.5%)、高脂+脂肪酶+乳化剂饲料(HLEE)、低脂+脂肪酶+乳化剂饲料(LLEE),养殖时间为56 d。结果发现:①HLEE组和LLEE组罗非鱼的增重率分别HL组和LL组提高6.77%、9.51%,特定生长率分别较其对照组提高3.75%、5.18%(P<0.05)。②HLEE组和LLEE组罗非鱼胃、肝、肠中蛋白酶的活性较HL组和LL组显著提高,而HLEE组和LLEE组的饲料系数显著低于HL组和LL组(P<0.05)。③HLEE组罗非鱼血清中ALT活性较HL组显著降低,LLEE组罗非鱼血清中TP浓度和肝脏中MDA的含量较LL组显著降低(P<0.05)。④组织切片结果表明,脂肪酶和乳化剂的添加减少了肝细胞的空泡化,缓解了肝脏的病变程度。由此可以得出,在饲料中添加脂肪酶和乳化剂可以在一定程度上节约罗非鱼饲料中的脂肪,改善肝脏的健康状况。

The present study was conducted for 56 days to investigate the fat-sparing effect by lipase and emulsifier combination in the feed of tilapia.The total of 360 fishes[(40.55±0.14)g]were randomly divided into four groups in triplicated.They were fed by high-lipid diet(HL,lipid was 8.0%),low-lipid diet(LL,lipid was 7.5%),high-lipid diet with lipase and emulsifier(HLEE)and low-lipid diet with lipase and emulsifier(LLEE),respectively.The results showed:①the growth of tilapia was significantly improved by the combination of lipase and emulsifier,reflecting by 6.77% and 9.51%,respectively increasement of body weight gain and 3.57% and 5.18%,respectively increasement of SGR in HLEE and LLEE groups than those of HL and LL groups;②protease activity in the stomach,liver and intestine were higher in lipase and emulsifier groups(HLEE and LLEE)than that in lipase and emulsifier-free groups(HL and LL),while FE was lower in fish fed HLEE and LLEE than the fish fed HL and LL;③plasma ALT of tilapia was decreased by lipase and emulsifier in high lipid group,and plasma TP and hepatic MDA were decreased significantly by lipase and emulsifier in low lipid group;④Histologically lipase and emulsifier supplement also improved morphology of liver,which significantly decreased vacuolation of liver cells and alleviated the damage on liver cells caused by disease.In conclusion,combined application of lipase and emulsifier could reduce dietary lipid to a certain extent without negative effects on growth,and even benefit for improving liver health for tilapia.