2023, Vol. 8, Special Issue 1, Part A

Year round study was made by covering six numbers of raceways (European type) at different locations in the farmer’s field with an average altitude of approximately 1640 masl to evaluate the growth performance of rainbow trout (Oncorhynchus mykiss) fed on pelleted feed. All the studied raceways were of almost similar size (Length-70’, Width-12’ and Depth-6’) and stocked with about 2500 nos. (in each raceway) of rainbow trout fingerlings (average weight-10g and average length- 11cm). The fingerlings were fed with pelleted feed (protein content-45% and fat content-8% approximately) initially @ 4-5% of their body weight in three equal installments and readjusted to 2-3% considering the feed utilization by the fishes. Water diverted from the natural streams were used with a flow of 3-4L/second and maintained by the farmers throughout the year. Growth performance of rainbow trout was evaluated in terms of weight gain (WG %), specific growth rate (SGR %), food conversion ratio (FCR) and survival rate. Trout showed an average WG of 2858%, SGR of 0.94% with FCR of 1.5. Highest growth performance was recorded during summer (April-September) with increased water temperature (20 °C on average), while a retarded growth recorded during winters (October-March) due to low water temperature (6 °C). However, on average farmers got 296gm fishes after one year of cultivation. The cost benefit parameter study showed a profit of Rs. 215/kg trout and was recorded with investment of Rs. 185/kg trout production cost (includes seed and feed cost only) which indicates 216% profit over actual expenditure obtained by the trout farmers within this period. The results obtained in present study are encouraging for farmer’s, however more profit may be gained by them with utilizing some other feeds with lower FCR or using some other locally available live/other feed resources.