不同加工工艺的饲料对大菱鲆幼鱼生长及养殖水环境的影响

比较了两种加工工艺对饲料(D1、D2)颗粒物理性状的影响,并用其投喂初始体重为16 g的大菱鲆幼鱼64 d,比较其对大菱鲆幼鱼生长、饲料利用和养殖水环境的影响。结果显示,D2组饲料平均颗粒直径、平均百粒重和水中稳定性显著高于D1组(P0.05),但其吸水性、堆积密度和沉降速度显著低于D1组(P0.05)。D2组大菱鲆幼鱼的增重率、特异生长率、摄食率及蛋白质效率显著高于D1组(P0.05)。大菱鲆对D2组饲料中干物质和粗蛋白的表观消化率显著高于D1组(P0.05),但对粗脂肪和总磷的表观消化率无显著影响(P0.05)。投喂18 h后,养殖水体中N、P含量均有了显著升高,D2组每升水中每千克鱼产生的亚硝酸氮含量显著高于D1组(P0.05),但硝酸氮和总氮增加量显著低于D1组(P0.05);D2组活性磷酸盐及总磷酸盐增加量显著低于D1组(P0.05)。研究结果表明,不同的加工工艺显著影响了颗粒饲料的物理性状和饲料利用,并对养殖水环境造成了影响。

Effects of different feed processing on the growth and the aquaculture environment of turbot juvenile Scophthalmus maximus

Feed processing technology was a main factor which affects the quality of feed particle and its utilization by cultured animals. In this study, we compared two feed produced with different processing technologies in terms of their physical properties, their effects on the growth of turbot juvenile, and their effects on feed utilization and the aquaculture environment. Two kinds of diets （ D1 and D2 ） were fed to turbot juvenile Scophthalmus maximus with initial weight of 16 g for 64 d. D2 showed significantly higher values than D1 （P 〈 0. 05 ） in the average diameter of feed pellets, the average weight of 100 feed pellets, and the water stability, but also showed significantly lower values regarding the water absorption, the bulk density, and the settling velocity （ P 〈 0. 05 ）. The weight gain rate, specific growth rate, feed intake rate, and protein efficient rate of turbot juvenile fed with D2 were all significantly higher than the D1 group （ P 〈 0. 05 ）. The apparent digestibility coefficient （ADC） of dry matter and crude protein of D2 group was also significantly higher than D1 group （ P 〈 0.05 ）. However there were no differences in ADCs of crude lipid and total phosphorus between the two groups （P 〉0. 05 ）. The nitrogen and phosphorus levels in the aquarium increased significantly after 18 h feeding. The nitrite nitrogen per liter water produced by one kilogram of D2 fish was significantly high- er than that produced by D1 fish （ P 〈 0. 05 ） ; whereas the nitrate nitrogen and the total nitrogen produced by D2 were significantly lower （P 〈 0. 05 ）. The labile phosphate and total phosphate produced by D2 group were also significantly lower than those of D1 group （ P 〈 0. 05 ）. The results suggested that the physical properties of feed pellets, the feed utilization, and the aquaculture environment could be all affected by different processing techniques.