GROWTH PERFORMANCE AND MEAT QUALITY OF LABEO ROHITA , CATLA CATLA AND CYPRINUS CARPIO UNDER DIFFERENT TREATMENTS

Abstract

A polyculture experiment was carried out to compare the growth performance and meat quality of Labeo rohita, Catla catla and Cyprinus carpio, under the influence of fertilization and supplementary feed in various combinations was conducted in earthen ponds having area of 0.02 ha with two replications for each treatment. After preliminary preparation of ponds, each pond was stocked with Labeo rohita, Catla catla and Cyprinus carpio in the ratio of 20:15:15, respectively. In this experiment, all the ponds received the same quantity of N but the sources were different. The amount of organic manure, fertilizer and supplementary feed was calculated on N-equivalence of 0.2g N/100g body weight of fish weekly for cow manure,nitrophos and daily basis for supplementary feed. In pond 1 100% nitrogen was taken from organic manure (cow manure) and in pond 2, 100% nitrogen was taken from inorganic fertilizers (nitrophos). In pond 3, 50% nitrogen was taken from cow manure and 50% from nitrophos whereas in pond 4, 50% nitrogen was taken from cow manure and 50% from supplementary feed. In case of pond 50, 50% nitrogen was taken from nitrophos and 50% from supplementary feed. Pond 6 received the 25% nitrogen from cow manure, 25% from nitrophos and 50% from supplementary feed under different treatments. The supplementary feed was formulated for treatments T 4 , T 5 and T 6 having 30% crude protein by using fish meal, rice polish, sunflower meal, maize gluten (30% C.P.), canola oil, vitamin and minerals premix. The following parameters viz., total body weight, total length, condition factor, specific growth rate (SGR), length-weight relationship, nitrogen conversion ratio (NCR), nitrogen incorporation efficiency(NIE), gross and net fish production, cost-benefit analysis, of these three fish species were recorded on monthly basis. At the final harvest, the proximate composition of fish meat sample was studied. Labeo rohita, Catla catla and Cyprinus carpio showed the minimum average body weight of 16.3, 16.5, 17.1, 16.5, 16.1 and 16.4g; 18.6, 19.1, 18.7, 18.9, 18.3 and 19.1g and 24.5, 24.9, 24.7, 24.7, 24.3 and 24.3g The maximum average body weight of Labeo rohita, Catla catla and Cyprinus carpio were recorded as 933.7, 923.1, 974.8, 931.9, 1024.6 and 1215.0g; 972.1, 890.6, 1073.0, 1181.0, 1038.7 and 1256.7g and 1013.7, 921.3, 992.6, 1105.8, 992.4 and 1119.0g in Catla catla showed the maximum growth performance (1256.7g) in T 6 receiving cow manure, nitrophos and supplementary feed. Labeo rohita showed the second highest (1215.0g), while in case of Cyprinus carpio, it was comparatively lesser (1119.0g) as compared to other two species. Labeo rohita showed the highest specific growth rate as (1.177%) followed by Catla catla (1.147%) and C. carpio (1.049%) in T 6 receiving cow manure, nitrophos and supplementary feed. Among the different treatments, the highest gross fish production of Labeo rohita, Catla catla and Cyprinus carpio were recorded as 2996.53 kg -1 ha -1 year -1 in T 6 receiving cow manure, nitrophos and supplementary feed amongst the treatments. The physicochemical charactersitics of pond water remained within the favourable limits for fish culture. Among these different treatments, T 6 under the influence of fertilization and supplementary feed is appeared to be optimal and best , as it significantly enhanced the fish growth rate, specific growth rate, fish production and other growth parameters as compared to the other treatments. From the above conclusion, manipulation of Cyprinus carpio along with the major carps and the provision of supplementary feed and fertilization enhanced the growth rate, production, meat quality a in semi intensive culture system. Furthermore it increased the effectiveness of liming application and the availability of nutrients to phytoplankton and zooplankton for the fish species in polyculture system which is helpful in reduction of the input costs.