不同饲料对星康吉鳗幼鱼生长、体成分和消化酶活性的影响

Influence of various diets on growth,body composition and digestive enzyme activities of juvenile white-spotted conger(Conger myriaster)

为了研制星康吉鳗(Conger myriaster)配合饲料,进行了不同饲料对星康吉鳗(体质量为53.98 g±1.23 g)生长性能、体成分和消化酶活性的影响试验,设置日本鳗鲡(Anguilla japonica)配合饲料处理组(饲料1,添加了3%虾糠和14%鱼粉)、日本鳗鲡配合饲料(饲料2)、玉筋鱼(Ammodytes personatus)(饲料3)、方氏云鳚(Enedras fangi)(饲料4)、玉筋鱼+方氏云鳚混合料(饲料5)5种试验饲料组,每种饲料组设置3个平行,每个平行放置26尾鱼,养殖试验共进行40 d。结果表明:饲料1、2组星康吉鳗的特定生长率与增重率显著低于饲料3、5组(P<0.05),饲料系数显著高于饲料3、4、5组(P<0.05),干物质及粗蛋白质、粗脂肪表观消化率也显著低于饲料3、4、5组(P<0.05);随着饲料中粗脂肪、总糖水平的升高,鱼体的粗脂肪、总糖含量呈上升趋势,其中,饲料1、2组的鱼体粗脂肪含量显著低于饲料3、5组(P<0.05),总糖含量显著高于饲料4、5组(P<0.05);饲料1、2组星康吉鳗胃、前肠、中肠和后肠的胰蛋白酶活性显著低于饲料4组(P<0.05),前肠和中肠的脂肪酶活性显著低于饲料3、5组(P<0.05),胃、前肠、中肠和后肠的淀粉酶活性显著高于饲料3、4、5组(P<0.05)。研究表明,饲喂玉筋鱼、方氏云鳚、玉筋鱼+方氏云鳚混合料组的星康吉鳗,其生长性能、饲料系数、饲料表观消化率(干物质、粗蛋白质、粗脂肪),以及胰蛋白酶和脂肪酶活性均优于饲喂日本鳗鲡配合饲料处理组和日本鳗鲡配合饲料组,其中饲喂玉筋鱼组的投喂效果最佳,建议参考玉筋鱼的营养成分组成,开发星康吉鳗的商品饲料配方。

In order to develop commercial feed for white-spotted conger(Conger myriaster),the white-spotted conger with body weight of(53.98 g±1.23 g)were reared in 600 L buckets in indoor breeding workshop at stocking density of 15 fish and fed commercial feed for Japanese eel(Anguilla japonica)supplemented with 3%of shrimp bran+14%of fishmeal(diet 1),A.japonica commercial feed(diet 2),trash fish Ammodytes personatus(diet 3),Enedras fangi(diet 4),and mixture of A.personatus+E.fangi(diet 5)at water temperature of 25.6-27.4℃for 40 days to investigate effects of different diets on the growth performance,feed utilization,body composition and digestive enzyme activities.The results showed that the fish fed diet 1 and diet 2 had significantly low specific growth rate and weight gain rate compared to the fish fed diet 3 and diet 5(P<0.05).There was significantly higher feed conversion ratio in diet 1 and diet 2 groups than that in diet 3,diet 4,and diet 5 groups(P<0.05),with significantly low apparent digestibility and absorption rate of dry matter,crude protein and crude fat in fish fed diet 1,and diet 2 compared to fish fed diet 3,diet 4 and diet 5(P<0.05).With the increase in dietary crude fat and total sugar levels,the crude fat and total sugar contents in the fish showed an upward trend,with significantly low crude fat levels in the fish fed diet 1 and diet 2 compared to those in diet 3 and diet 5 groups(P<0.05).The fish total sugar content was shown to be significantly higher in diet 1 and diet 2 groups than in diet 4 and diet 5 groups(P<0.05).There was significantly lower trypsin activity in the stomach,foregut,midgut and hindgut in diet 1 and diet 2 groups than those in diet 4 group(P<0.05),with significantly lower lipase activity in foregut and midgut in the fish fed diet 1 and diet 2 than that in diet 3 and diet 5 groups(P<0.05).The significantly higher amylase activity in stomach,foregut,midgut and hindgut was observed in diet 1 and diet 2 groups than that in diet 3,diet 4 and diet 5 groups(P<0.05).In conclusion,the significantly better growth performance,feed coefficient,feed apparent dry matter,rude protein,and crude lipid digestibility,trypsin activity and lipase activity were observed in the fish fed A.personatus,E.fangi and A.personatus+E.fangi mixed than the fish fed A.japonica commercial feed treatment group and A.japonica commercial feed,with the best feeding effect in A.personatus group.It is recommended to develop an ideal practical feed formulation for C.myriaster based on the nutrient characteristics of A.personatus.