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EFFECT OF DIETARY OMEGA-3 FATTY ACID DIETS ON GROWTH AND PHYSICO-CHEMICAL PARAMETERS OF CULTURED WATER IN FINGERLINGS OF LABEO ROHITA

Prathibha Bharathi, Chittem and Sumanth Kumar Kunda

Fish is a rich source of polyunsaturated fatty acids (PUFA’s) viz. n-6 and n-3 PUFA’s, which are beneficial to human health. Rohu considered to be the most important of the “Indian Major Carps” and is the world’s 10th highest cultured finfish by production volume. Essential fatty acids such as omega-3 fatty acids (EPA and DHA) play a vital role in fish nutrition. To understand the role of the dietary Omega-3 fatty acids diets in fingerlings of Labeo rohita, a 60 days experiment was carried out. 300±20 fingerlings of rohu were randomly distributed in five treatment groups consisting of three replicates of each. Five isonitrogenous (protein 19.60g) and isocaloric (337 k cal/ 100 g) experimental diets viz. Control (basal diet), T1 (basal + 1% ω-3 fatty acid), T2 (basal + 3% ω-3 fatty acid), T3 (basal + 5% ω-3 fatty acid) and T4 (basal + 7% ω-3 fatty acid) were prepared with graded levels of omega-3 fatty acids. These were fed to rohu fingerlings (average body weight 1.793 ± 0.022g) twice a day. Sampling of water from all the experimental groups were carried out to estimate water quality parameters viz temperature, PH, dissolved oxygen, free carbon dioxide, total hardness, ammonia, nitrite and alkalinity. These were recorded for every 15 days interval. The water in each tank was changed (80%) daily and replenished with fresh water, for each tank. The results indicated that the fishes which received the feed T1 (127.4±0.1) consisting of 1% of ω-3 fatty acid showed significantly increase of average body weight and specific growth rates (SGR) compared to control and other treatments T2 (120.1±0.3), T3 (112.6±0.3) and T4 (109.0±0.3). The experimental conditions, T1 feed (1% omega-3 fatty acid) had showed better growth amongst the treatments and increase of beyond 1% omega-3 fatty acid had showed poor growth due to of nutrients in general, omega-3 fatty acid in particular. Supplementation of omega-3 fatty acid in the aquaculture diets would also helps maintain the optimum range of physico-chemical parameters of the reared water.