Open AccessEffects of dietary lipid-to-carbohydrate ratio on growth and carbohydrate metabolism in juvenile cobia (Rachycentron canadum)
Author(s) -
Huanxin Zhao,
Jiankang Cao,
Xiaoying Chen,
Guoxia Wang,
Junru Hu,
Bing Chen
Publication year - 2020
Publication title -
animal nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 28
eISSN - 2405-6545
pISSN - 2405-6383
DOI - 10.1016/j.aninu.2019.11.010
Subject(s) - protein efficiency ratio , carbohydrate , malic enzyme , feed conversion ratio , triglyceride , biology , fructose , juvenile , zoology , medicine , endocrinology , carbohydrate metabolism , biochemistry , enzyme , body weight , cholesterol , ecology , dehydrogenase
This experiment was conducted to investigate the effects of dietary lipid-to-carbohydrate ratio on growth and carbohydrate metabolism in juvenile cobia ( Rachycentron canadum ). Six isonitrogenous diets were prepared to vary in lipid-to-carbohydrate ratio (g/g) as follows: D1, 2.26; D2, 1.31; D3, 0.78; D4, 0.47; D5, 0.34; and D6, 0.23. Cobias were fed to satiety for 8 weeks. The weight gain and protein efficiency ratio in D1 group were significantly lower than those in other groups ( P < 0.05), accompanied by a lower level of feed conversion ratio ( P < 0.05). Protein retention efficiency in D4 and D6 and whole body protein in D4 and D5 were significantly higher than those in D1 group ( P < 0.05). Survival rate in D4 group was the highest among all groups and was significantly higher than that in D1, D2 and D5 ( P < 0.05). In terms of serum triglyceride, D1 and D2 were significantly higher than D6 ( P < 0.05). Hepatosomatic index in D3 and D4 was significantly lower than that in D1 ( P < 0.05). Fructose-1,6-diphosphatase in D4 was significantly higher than that in D1 and D3 ( P < 0.05). Phosphofructokinase in D3 and D4 and malic enzyme in D4 and D5 were significantly higher than those in other groups ( P < 0.05). Results indicate that cobia utilizes carbohydrates as energy source more efficiently than it utilizes lipids. The optimal lipid-to-carbohydrate ratio in juvenile cobia diets is 0.47.