海洋科学2016，Vol.40Issue(3)：87-94,8.DOI:10.11759/hykx20150602002
饲料蛋白质水平对拟目乌贼生长前期的生长性能、肌肉成分和酶活的影响
Effects of dietary protein level on growth, muscle composition, and enzyme activity of Sepia lycidas during early growth period
摘要
Abstract
In this study, we determined the effects of the dietary protein level on the growth rate, muscle composi-tion, and activities of digestive and liver enzymes of Sepia lycidas during the early growth period of the lifecycle. Six experimental diets were formulated, including fishmeal, soybean mean, and gelatine as protein sources, at various protein levels (31.5%, 35.0%, 38.5%, 42.0%, 45.5%, and 49.0%). Totally 540 Sepia lycidas with an average body weight of 3.99 ± 0.08 g were randomly assigned into these six dietary groups; this produced groups containing thirty fish with three replicates, providing a total of ninety fish per group. It was found that at the 45.91% protein level, Sepia lycidas achieved the optimum growth rate. At this protein level, the weight gain rate, special gain rate, and survival rate showed significant difference from all other protein groups (P<0.05), with the exception of the 49.72% group (P>0.05). Along with the increase of the dietary protein level, the feed conversion ratio initially de-creased and then increased, with the lowest value found at the 45.91% protein level, which is significantly lower than those of the other groups (P<0.05), with the exception of the 49.72% group (P>0.05). The protein efficiency ratio significantly decreased as the dietary protein level increased (P<0.05). The condition factor and hepatosomatic index in muscles were not affected by the dietary protein level (P>0.05). As the protein level was increased up to 45.91%, the activities of protease, trypsin, lipase, and hepatic superoxide dismutase (SOD) increased and were sig-nificantly higher than those of other groups (P<0.05). Lipase and SOD continued to increase and showed the maximum activity at the 49.72% (P>0.05) protein level. Meanwhile, the intestinal amylase activity showed the op-posite trend. Levels of hepatic glutamate pyruvate transaminase and glutamic oxaloacetic transaminase initially increased before reaching a plateau, with the highest values being observed at the 49.72% dietary protein level, which was significantly higher than those of other groups (P<0.05), with the exception of values at the 45.91% die-tary protein level (P>0.05). The alkaline phosphatase activity was not found to be affected by the dietary protein level (P>0.05). Sepia lycidas achieved the highest crude protein content at the 45.91% dietary protein level, which was significantly higher than those at other levels (P<0.05), with the exception of the 45.91% level (P>0.05). Juve-nile Sepia lycidas had the lowest crude lipid content in muscles. The dietary protein levels had no significant effect on the moisture and ash content in muscles (P>0.05). Results indicated that the 45.91% dietary protein level was sufficient to satisfy the growth requirements of Sepia lycidas during the early growth period.关键词
拟目乌贼(Sepia lycidas)/蛋白质水平/生长性能/肌肉成分/酶活Key words
Sepia lycidas/protein level/growth/muscle composition/enzyme activities分类
农业科技引用本文复制引用
汪元,蒋霞敏,乐可鑫,韩庆喜,彭瑞冰,梁晶晶,王鹏帅..饲料蛋白质水平对拟目乌贼生长前期的生长性能、肌肉成分和酶活的影响[J].海洋科学,2016,40(3):87-94,8.基金项目
国家农转化项目(2009GB2C220415) （2009GB2C220415）
浙江省种质种苗项目(浙海渔计2013-82) （浙海渔计2013-82）
宁波市农业重大专项(2014C11001)@@@@Agriculture Science Technology Achievement Transforma-tion Project of China, No.2009GB2C220415 （2014C11001）
Zhejiang Province Germ-plasm and Germchit Project, No.2013-82 （）
Ningbo Agriculture Major Project, No.2014C11001 （）
