Open AccessOptimal dietary carbohydrate‐to‐lipid ratios for silvery‐black porgy ( Sparidentex hasta ) juveniles
Author(s) -
Torfi Mozanzadeh M.,
Yavari V.,
Marammazi J.G.,
Agh N.,
Gisbert E.
Publication year - 2017
Publication title -
aquaculture nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 79
eISSN - 1365-2095
pISSN - 1353-5773
DOI - 10.1111/anu.12415
Subject(s) - biology , carbohydrate , polyunsaturated fatty acid , lipid peroxidation , alkaline phosphatase , medicine , antioxidant , zoology , lysozyme , endocrinology , food science , biochemistry , enzyme , fatty acid
Four isonitrogenous diets containing different carbohydrate:lipid ( CHO :L) ratios (0.3, 0.6, 1.1 and 1.8) were tested in triplicate groups (16 fish per replicate) of silvery‐black porgy juveniles for 8 weeks. Growth performance was not affected by different dietary CHO :L ratios ( P > 0.05); however, the viscerosomatic index, the intraperitoneal fat, whole‐body lipid, energy and n‐3 long chain polyunsaturated fatty acids levels increased with decreasing dietary CHO :L ratios ( P < 0.05). Fish fed with 1.8 CHO :L diet had the lowest apparent digestibility coefficients of protein and lipid, as well as the lowest plasma haemolytic and lysozyme activities ( P < 0.05). Red blood cell counts and plasma glucose levels were higher in fish fed with 1.1 and 1.8 CHO :L ratio diets than in the other groups ( P < 0.05). Plasma alkaline phosphatase and alanine aminotransferase, as well as the level of lipid peroxidation and total antioxidant capacity in the liver and plasma increased as dietary CHO :L ratios decreased ( P < 0.05). The results of the current study indicated that the diets with CHO :L ratios between 0.6 and 1.1 are optimal for silvery‐black porgy, whereas higher ratios may result in hyperglycaemia and immune suppression, and lower CHO :L ratios may lead to oxidative stress and liver dysfunction.