Dietary leucine requirement for juvenile large yel

Authors: Yan Li Qinghui Ai Kangsen Mai Wei Xu Zhenyan Cheng Zhigang He

Publish Date: 2010/10/30

Volume: 9, Issue: 4, Pages: 371-375

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Abstract

Dietary leucine requirement for juvenile large yellow croaker Pseudosciaena crocea Richardson 1846 initial body weight 60 g ± 01 g was determined using doseresponse method Six isonitogenous crude protein 43 and isoenergetic 19 kJ g−1 practical diets containing six levels of leucine Diets 1–6 ranging from 123 to 480 dry matter were made at about 07 increment of leucine Equal amino acid nitrogen was maintained by replacing leucine with glutamic acid Triplicate groups of 60 individuals were fed to apparent satiation by hand twice daily 0500 and 1730 The water temperature was 26–32°C salinity 26–30 and dissolved oxygen approximately 7 mg L−1 during the experimental period Final weight FW of large yellow croaker initially increased with increasing level of dietary leucine but then decreased at further higher level of leucine The highest FW was obtained in fish fed diet with 330 Leucine Diet 4 FW of fish fed the diet with 480 Leucine Diet 6 was significantly lower than those fed Diet 4 However no significant differences were observed between the other dietary treatments Feed efficiency FE and whole body composition were independent of dietary leucine contents P 005 The results indicated that leucine was essential for growth of juvenile large yellow croaker On the basis of FW the optimum dietary leucine requirement for juvenile large yellow croaker was estimated to be 292 of dry matter 679 of dietary protein

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