title: Effect of dietary lysine on growth, intestinal enzymes activities and antioxidant status of sub-adult grass carp (Ctenopharyngodon idella).
abstract: The dietary lysine requirement of sub-adult grass carp (460 ± 1.5 g) was assessed by feeding diets supplemented with grade levels of lysine (6.6, 8.5, 10.8, 12.9, 15.0 and 16.7 g kg(-1) diet) for 56 days. The test diets (28% CP) contained fish meal, casein and gelatin as sources of intact protein, supplemented with crystalline amino acids. Weight gain (WG), feed intake and feed efficiency were significantly improved with increasing levels of lysine up to 12.9 g kg(-1) diet and thereafter declined (P < 0.05). Quadratic regression analysis of WG at 95% maximum response indicated lysine requirement was 10.9 g kg(-1) diet. Activities of trypsin, chymotrypsin, lipase, Na(+), K(+)-ATPase and alkaline phosphatase in intestine, creatine kinase activity in proximal and mid-intestine responded similar to WG (P < 0.05). In addition, lipid and protein oxidation decreased with increasing levels of lysine up to certain values and increased thereafter (P < 0.05); the anti-hydroxyl radical capacity, dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase (GST) activities and glutathione content were increased with increasing dietary lysine levels up to certain values in the detected tissues, except for hepatopancreatic GST. Requirement estimated on the basis of malondialdehyde content in intestine and hepatopancreas was 10.6 and 9.53 g lysine kg(-1) diet, respectively.
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Ya'an, 625014, Sichuan, China.
authors.forename: Xue-Yin
authors.initials: XY
authors.lastname: Li
authors.forename: Ling
authors.initials: L
authors.lastname: Tang
authors.forename: Kai
authors.initials: K
authors.lastname: Hu
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Wei-Dan
authors.initials: WD
authors.lastname: Jiang
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.forename: Pei
authors.initials: P
authors.lastname: Wu
authors.forename: Gang-Fu
authors.initials: GF
authors.lastname: Chen
authors.forename: Shu-Hong
authors.initials: SH
authors.lastname: Li
authors.forename: Sheng-Yao
authors.initials: SY
authors.lastname: Kuang
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
authors.forename: Xiao-Qiu
authors.initials: XQ
authors.lastname: Zhou
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D017756:Aquaculture; D002347:Carps / Q000254:growth & development / Q000378:metabolism*; D004032:Diet; D029941:Fish Proteins / Q000378:metabolism*; D007422:Intestines / Q000201:enzymology* / Q000254:growth & development; D008239:Lysine / Q000008:administration & dosage*; D008871:Microvilli / Q000201:enzymology; D009132:Muscles / Q000201:enzymology; D017855:Transferases (Other Substituted Phosphate Groups) / Q000378:metabolism
chemical_list: D000975:Antioxidants; D029941:Fish Proteins; D019883:Alkyl and Aryl Transferases; C112459:geranylpyrophosphate olivetolate geranyltransferase; D017855:Transferases (Other Substituted Phosphate Groups); C106504:UDP-GlcNAc-undecaprenyl phosphate N-acetylglucosaminyl 1-phosphate transferase; D008239:Lysine