The relationship between dietary methionine and growth, digestion, absorption, and antioxidant status in intestinal and hepatopancreatic tissues of sub-adult grass carp (Ctenopharyngodon idella)

Table 8 Estimated dietary methionine requirements for sub-adult grass carp

Fish weight, g	Response variables	Model	Estimated Met requirements (0.95 confidence limits)
Sub-adult grass carp 450-1, 170	Feed intake	Quadratic regression	7.04 g/kg diet, 25.09 g/kg protein
	Muscle GPT activity	Quadratic regression	5.79 g/kg diet, 20.63 g/kg protein
	AKP activity in PI	Quadratic regression	5.59 g/kg diet, 19.92 g/kg protein
	AKP activity in MI	Linear regression	7.11 g/kg diet, 25.35 g/kg protein
	γ-GT activity in DI	Linear regression	5.73 g/kg diet, 20.43 g/kg protein
	CK activity in PI	Quadratic regression	5.47 g/kg diet, 19.49 g/kg protein
	Hepatopancreatic GST activity	Quadratic regression	6.39 g/kg diet, 22.77 g/kg protein
	Intestinal PC content	Quadratic regression	4.51 g/kg diet, 16.07 g/kg protein
	Intestinal AHR activity	Quadratic regression	4.83 g/kg diet, 17.21 g/kg protein

GPT glutamate-pyruvate transaminase, AKP alkaline phosphatase, γ-GT γ-glutamyl transpeptidase, CK creatine kinase, PC protein carbonyl, AHR anti-hydroxy radical, GST glutathione-S-transferase, PI proximal intestine, MI mid intestine, DI distal intestine

ISSN: 2049-1891