Effect of different dietary protein level on growth, production and survivability of threatened Mystus cavasius (Hamilton-Buchanan 1822) in pond habitat

Abstract

A study was undertaken to determine the effect of different dietary protein levels on growth, survival and production of Mystus cavasius (Hamilton-Buchanan 1822) with three experimental diets containing 29%, 32% and 35% protein level applied simultaneously to three treatments T₁, T₂ and T₃ respectively each with three replications. The stocking density (1, 11, 150/ha), initial weight (3.00±00 g) and length (2.00±0.00 cm) of fish were same for all the treatments. No significant (P>0.05) difference was found for the mean values of water quality parameters. A suitable range of water quality parameters were recorded with the environment of experimental ponds. In terms of growth, production and survival, relatively highest performance was found in the treatment T₃. After 180 days of rearing, average weight gain was 29.16±0.43 g, 31.17±0.30 g and 37.44±0.32 g with the above three different feeds, respectively. The average daily gain (ADG) and specific growth rate (SGR) of all treatments showed significant difference (P<0.05) and the highest value (0.21±0.04 and 1.43±0.01%) was found with the 35% dietary protein level containing diet. Feed conversion ratio (FCR) improved with increase of dietary protein. The findings of FCR were 2.97±0.02 at 29% protein level (T₁), 2.64±0.02 at 32% protein level (T₂) and 2.20±0.01 at 35% protein level (T₃). The results of protein efficiency ratio (PER) values were fairly similar of 1.17±0.02 and 1.18±0.01 for 29% and 32% protein level containing diets respectively indicating low efficiency and the highest efficiency (1.30±0.01) was found with 35% protein level. The findings of condition factor in different treatments for Mystus cavasius were not significantly (P>0.05) varied with the treatments. Calculated values of condition factor were 1.04±0.00, 1.03±0.03 and 1.09±0.05 in treatment T₁, T₂ and treatment T₃, respectively. In pond culture, the performance of treatment T₃ was found to be better than the treatment T₁ and T₂. The production was of 3616±16.74 kg/ha in T₃ during the culture period of six months. The best cost benefit ratio (CBR) value (1.98±0.02) was also found with treatment T₃. The 35% dietary protein level with treatment T₃ resulted in best growth performance and was probably adequate to meet the dietary protein needs of Mystus cavasius (Hamilton-Buchanan, 1822).

Asian J. Med. Biol. Res. December 2020, 6(4): 659-673