文献类型：期刊文献

英文题名：Dietary lysine requirement of juvenile cobia (Rachycentron canadum)

作者：Zhou, Qi-Cun[1];Wu, Zao-He[1];Chi, Shu-Yan[1];Yang, Qi-Hui[1]

机构：[1]Guangdong Ocean Univ, Lab Aquat Econ Anim Nutr & Feed, Coll Fisheries, Zhanjiang 524025, Peoples R China

年份：2007

卷号：273

期号：4

起止页码：634

外文期刊名：AQUACULTURE

收录：SCI-EXPANDED(收录号：WOS:000252299300028)、、Scopus(收录号：2-s2.0-36649035075)、WOS

基金：The authors are grateful for financial support by Grant No. 2002AA603012 from The National High Technology Research and Development Program (863 Program). This manuscript was greatly improved thanks to Dr. Z. Luo. We would also like to thank C. C. Li and J. B. Zhou for their assistance with sampling.

语种：英文

外文关键词：juvenile cobia (Rachycentron canadum); lysine; growth performance; feed utilization

外文摘要：An 8-week feeding trial was conducted to quantify the dietary lysine requirement of juvenile cobia with an initial average weight of 1.25 g reared in indoor flow-through and aerated aquaria. Six isonitrogenous and isoenergetic practical diets (44% CP and 16% lipid) containing six levels of dietary lysine ranging from 1.15 to 3.25% (dry weight) at about 0.4% increments, using fish meal and wheat gluten as sources of intact protein, supplemented with crystalline amino acids. Equal amino acid nitrogen was maintained by replacing lysine with nonessential amino acid mixture. Each diet was randomly assigned to three aquaria and was fed to apparent satiation by hand four times daily. The results indicated that there were significantly differences in growth performance and feed utilization among the treatments. Maximum weight gain, special growth rate and protein efficiency ratio occurred at 2.38% dietary lysine; but with the increase of dietary lysine from 2.38 to 3.25%, weight gain, special growth rate and protein efficiency ratio did not significantly increase. The hepatosomatic index, viscerosomatic index, condition factor, crude protein content in whole body and main composition in muscle were significantly affected by dietary lysine levels; however moisture, lipid and ash content in whole body were not significantly affected by the dietary lysine. There were significant differences in total serum protein, glucose and triacyglycerol concentrations in fish fed diets with different dietary lysine levels. Haematocrit and leukocyte count were significantly affected by dietary lysine level, but hemoglobin and red blood cell count were not significantly affected. Lysine concentration in serum was significantly increased with the increase of dietary lysine level from 1.15 to 2.38%. Broken-line analysis on the basis of special growth rate showed that the dietary lysine requirement of juvenile cobia was 2.33% of dry diet (5.30% dietary protein). (c) 2007 Published by Elsevier B.V.