Effect of Dietary Gelatinized Starch Level and Rearing Temperature on Fatty Acid Profile and DNA:RNA Ratio of Labeo rohita (Hamilton) Fingerlings

A 60-day feeding trial was conducted to delineate the effect of three dietary levels of gelatinized starch on fatty acid profiles and RNA and DNA contents of fingerlings of the Indian major carp, Labeo rohita, reared at ambient water temperature (26±0.8°C) or 32°C. Two hundred and sixteen fingerlings (6.5±0.3 g) were randomly distributed into six treatments in triplicate. Three semi-purified isonitrogenous diets were prepared with 40%, 50%, or 58% gelatinized starch. Liver and muscle RNA and RNA:DNA ratio were significantly (p<0.05) higher in fish fed the 40% or 50% diet and reared in 32°C. DNA content did not significantly differ between treatments (p>0.05). Total saturated fatty acids (SAFA) in muscle was highest in fish fed the 50% diet; SAFA in fish fed the 58% diet were higher than in those fed the 40% diet but lower than in those fed the 50% diet. Polyunsaturated fatty acids (PUFA) were highest in fish fed the 40% diet. Total n-3 and n-6 fatty acids generally decreased as the level of starch increased; likewise, higher levels of gelatinized starch led to a reduced n-3:n-6 ratio. Rearing temperature had no significant effect on fatty acid composition of the muscle. RNA content and RNA:DNA ratio in the liver and muscle decreased gradually as the starch level increased. The IJA appears exclusively as a peer-reviewed on-line open-access journal at http://www.siamb.org.il. To read papers free of charge, please register online at registration form. Sale of IJA papers is strictly forbidden. Sale of IJA papers is strictly forbidden.