Evaluation of Mixed Feeding Schedules with Varying Dietary ProteinContent on the Growth Performance and Reduction of Cost of Productionfor Sutchi Catfish, Pangasius hypophthalmus, Sauvage, with SilverCarp, Hypophthalmichthys molitrix, Valenciennes

摘要

An on-station pond trial was conducted for 6 months to investigate the suitability of mixed feeding schedules with varying protein levels on the growth of sutchi catfish, Pangasius hypophthalmus with silver carp, Hypophthalmicthys molitrix with a view to minimizing the cost of production. Five different feeding regimes employed were: high protein diet (30% protein, H), low protein (15% protein, L), one day low protein diet followed by one day high protein diet (1L/1H), 7 day low protein diet followed by 7 day high protein diet (7L/7H), and 14 day low protein diet followed by 14 day high protein diet (14L/14H). Ten experimental ponds each of 0.008 ha size were divided into 5 treatment groups each with two replicates. Fishes were stocked at the ratio of 80:20 (sutchi catfish:silver carp) at the total rate of 25,000/ha. Feeding rate was calculated only on the basis of sutchi catfish weight only and fish were fed at the rate of 15, 10, 8, and 5% of their body weight for 1st, 2nd, 3rd months, and rest of the experimental period respectively. The ranges of water quality parameters during the study period were: temperature 22 degree C to 32.8 degree C, dissolved oxygen 4.30 to 7.44 mg/L, pH 6.85 to 7.50, and transparency 21.9 to 32.2 cm. The result of the study showed that significantly (P < 0.05) higher fish weight gain was achieved in feeding schedules of H and 1L/1H and lowest with 14L/14H. The FCR values ranged between 2.06 and 2.51 with H and 1L/1H showing significantly the best FCR. The FCR values were very low when weight of silver carp was considered which ranged between 1.58 and 1.68. The survivals (%) of sutchi catfish were lower (78.1 to 82.5%) compared to that of silver carp (90-95%). The total production of sutchi catfish ranged between 3594 and 7095 kg/ha and silver carp ranged between 1777 and 2220 kg/ha. A simple economic analysis showed that fish in 1L/1H fed alternately with low and high protein diets resulted in the highest net profit. The result of the study suggest that for profitable sutchi catfish farming in Bangladesh farmers can adopt a mixed feeding schedule of alternated low and high protein diet instead of continuously feeding a high protein diet.