摘要
Background： This study was carried out to investigate effects of threonine levels on growth, digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp （ Ctenopharyngodonidella）. Results： Weight gain, specific growth rate, feed intake and feed efficiency were significantly improved by dietary threonine （P 〈 0.05）. Intestinal activities of trypsin, chymotrypsin, alpha-amylase, lipase, alkaline phosphatase, y-glutamyl transpeptidase and creatine kinase took the similar trends. Contents of malondialdehyde and protein carbonyl in intestine and hepatopancreas were significantly decreased by dietary optimal threonine supplementation （P 〈 0.05）. Anti-superoxide anion capacity, anti-hydroxyl radical capacity, glutathione content and activities of superoxide dismutase, catalase and glutathione-S-transferase in intestine and hepatopancreas were enhanced by dietary threonine （P 〈 0.05）. Conclusions： Dietary threonine could improve growth, enhance digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp. The dietary threonine requirement of sub-adult grass carp （441.9-1,013.4 g） based on weight gain was 11.6 g/kg diet or 41.5 g/kg of dietary protein by quadratic regression analysis.
Background： This study was carried out to investigate effects of threonine levels on growth, digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp （ Ctenopharyngodonidella）. Results： Weight gain, specific growth rate, feed intake and feed efficiency were significantly improved by dietary threonine （P 〈 0.05）. Intestinal activities of trypsin, chymotrypsin, alpha-amylase, lipase, alkaline phosphatase, y-glutamyl transpeptidase and creatine kinase took the similar trends. Contents of malondialdehyde and protein carbonyl in intestine and hepatopancreas were significantly decreased by dietary optimal threonine supplementation （P 〈 0.05）. Anti-superoxide anion capacity, anti-hydroxyl radical capacity, glutathione content and activities of superoxide dismutase, catalase and glutathione-S-transferase in intestine and hepatopancreas were enhanced by dietary threonine （P 〈 0.05）. Conclusions： Dietary threonine could improve growth, enhance digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp. The dietary threonine requirement of sub-adult grass carp （441.9-1,013.4 g） based on weight gain was 11.6 g/kg diet or 41.5 g/kg of dietary protein by quadratic regression analysis.
基金
National 973 Project of China(2014CB138600)
National Department Public Benefit Research Foundation(Agriculture) of China (201003020)
Science and Technology Support Programme of Sichuan Province of China(2014NZ0003)
Major Scientific and Technological Achievement Transformation Project of Sichuan Province of China(2012NC0007 and 2013NC0045) for their financial support
