The eco-nutrition requirements for dietary protein and its rhomb characteristics in juvenile turbot (Scophthalmus maximus L.)  

作　　者：李勇 蒋克勇 孙国祥 高婷婷 周邦维 

机构地区：[1]Institute of Oceanology, Chinese Academy of Sciences

出　　处：《Chinese Journal of Oceanology and Limnology》2011年第5期1002-1008,共7页中国海洋湖沼学报（英文版）

基　　金：Supported by the National High Technology Research and Development Program of China (863 Program) (No. 2006AA100305);National Agricultural Science and Technology Achievements Commercialization Program (No. 2008GB2C100109);the Knowledge Innovation Program of Institute of Oceanology, Chinese Academy of Sciences (No. L49032503)

摘　　要：We evaluated the dietary protein requirements of juvenile turbot (Scophthalmus maximus L.) and their effects on aquatic quality. Five experimental diets were formulated containing 450, 480, 500, 520, and 540 g/kg. Each diet was randomly assigned to triplicate groups of juvenile turbot (mean initial body weight 34.5 ± 5.5 g) for 88 d. Both the weight gain ratio and feed efficiency increased with increasing dietary protein up to 500 g/kg, but no further improvement was detected when dietary protein levels were >500 g/kg. Protein intake and digestion increased with protein levels, while fecal nitrogen and nitrogen content in seawater increased only when dietary protein exceeded 500 g/kg. Protein digestibility was highest at intermediate dietary protein levels. Chemical oxygen demand, nitrite-nitrogen (NO2--N) and phosphatic-phosphor (PO43--P) levels increased in the rearing water as dietary protein levels increased. The optimum eco-nutrition level of dietary protein for juvenile turbot was 500 g/kg under the current experimental conditions. The diets containing 540 and 500 g/kg protein had similar growth rates and feed conversion ratios, but levels of ammonia (NH4+) and nitrogen were considerably higher in the water and feces, respectively, at the higher level of dietary protein. The difference in the pattern of change between body weight gain and ammonia concentration in water with increasing dietary protein is described by rhomb characteristics.We evaluated the dietary protein requirements of juvenile turbot （Scophthalmus maximus L.） and their effects on aquatic quality. Five experimental diets were formulated containing 450, 480, 500, 520, and 540 g/kg. Each diet was randomly assigned to triplicate groups of juvenile turbot （mean initial body weight 34.5±5.5 g） for 88 d. Both the weight gain ratio and feed efficiency increased with increasing dietary protein up to 500 g/kg, but no further improvement was detected when dietary protein levels were 〉500 g/kg. Protein intake and digestion increased with protein levels, while fecal nitrogen and nitrogen content in seawater increased only when dietary protein exceeded 500 g/kg. Protein digestibility was highest at intermediate dietary protein levels. Chemical oxygen demand, nitrite-nitrogen （NO2-N） and phosphatic-phosphor （PO43--P） levels increased in the rearing water as dietary protein levels increased. The optimum eco-nutrition level of dietary protein for juvenile turbot was 500 g/kg under the current experimental conditions. The diets containing 540 and 500 g/kg protein had similar growth rates and feed conversion ratios, but levels of ammonia （NH4） and nitrogen were considerably higher in the water and feces, respectively, at the higher level of dietary protein. The difference in the pattern of change between body weight gain and ammonia concentration in water with increasing dietary protein is described by rhomb characteristics.

关 键 词：eco-nutrition requirement rhomb characteristics protein aquatic quality DIGESTION TURBOT 

分 类 号：S963[农业科学—水产养殖]