Response to the ration levels on growth, body composition, energy, and protein maintenance requirement of the Indian catfish (Heteropneustes fossilis-Bloch 1974)

An 8-week growth study was conducted to determine the effect of ration level, energy, and protein maintenance requirement of catfish, Heteropneustes fossil's Bloch, fingerling (7 90 +/- 0 55 cm, 3 10 +/- 0 28 g) by feeding casein gelatin-based purified diet (40% CP, 3 61 kcal g-1 GE) at six ration levels 1-6% of BW/day, at 0800 and 1700 h, in triplicate, with 20 fish per trough fitted with water flow-through system of volume 55 L Maximum live weight gain, best feed conversion ratio (FCR), best specific growth rate (SGR), and highest protein efficiency ratio (PER) were evident for ration levels of 4-5% body weight However, second-degree polynomial regression analysis for weight gain, FCR, PER, protein, and energy retention data indicated that the break-points occurred at 5 08, 4 18, 405, 4 16, and 4 17% BW/day, respectively Significantly (P <0 05) higher body protein content was recorded at 4 and 5% rations While a linear increase in body fat content with inverse relationship in moisture content was evident with increasing rations Ash content remained insignificantly (P > 0 05) low at higher rations Protein and energy retention values also produced significant (P <0 05) differences Based on the results obtained, it is recommended that feeding in the range of 4 to 4 5% BW/day, corresponding to 1 60-1 80 g protein and 14 46-16 27 kcal energy g100 g(-1) of the diet/day is optimum for the growth and efficient feed utilization of H fossil's, while 2-3% ration levels (0 80-1 20 g protein and 7 23-10 84 kcal energy) suggest that these amounts approximate to the maintenance requirement of this fish