Dietary vitamin A requirement of juvenile greasy grouper ( Epinephelus tauvina)

• Published in: Aquaculture 2003-04, Vol.219 (1), p.693-701
• Main Authors: Shaik Mohamed, J, Sivaram, V, Christopher Roy, T.S, Peter Marian, M, Murugadass, S, Raffiq Hussain, M
• Format: Article
• Language: English
• Subjects: Animal aquaculture; Animal productions; Aquaculture; Biological and medical sciences; Diet; Epinephelus tauvina; Fish; Fundamental and applied biological sciences. Psychology; Greasy grouper; Marine; Nutrition; Pisciculture; Retinol; Vertebrate aquaculture; Vitamin A
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/S0044-8486(02)00665-8

A 10-week growth study was conducted to determine the dietary vitamin A requirement of juvenile greasy grouper. Eight semipurified diets containing 210, 476, 914, 1774, 3764, 7063, 14,342 and 29,193 IU vitamin A (as retinyl acetate)/kg diet were fed twice daily to triplicate groups (20 fish/group) of fish (initial weight 5.84±1.5 g/fish). Fish fed the basal diet (210 IU vitamin A/kg diet) developed haemorrhages in the skin overlaying the base of the fins and erosion on the caudal peduncle. None of these deficiency signs were observed in fish fed the vitamin A supplemented diets. Significantly higher weight gain, protein efficiency ratio and survival and lower feed conversion ratio were observed in fish fed the 3764 IU vitamin A/kg diet than fish fed the other diets. Whole body crude fat concentrations significantly decreased in fish fed increasing levels of dietary vitamin A. Addition of vitamin A to the basal diet did not significantly affect whole body protein and ash concentrations of the fish. However, dietary vitamin A supplementation did not significantly affect whole body moisture concentration. Serum vitamin A concentration was affected by dietary vitamin A level. Increasing serum vitamin A concentration was observed as dietary vitamin A level increased from 210 to 3764 IU/kg and tended to plateau in fish fed higher vitamin A levels. Broken-line regression analysis showed that juvenile greasy grouper require a minimum of 3101 IU vitamin A/kg diet for maximal growth. The associated serum vitamin A concentration was 179 μg/ml.