The trout is a cold-water fish found and reared in the NWFP and Northern Areas (Gilgit, Skardu and Chitral) of Pakistan, where two species, Brown trout (Salmo trutta) and Rainbow trout (Oncorhynchus mykiss), though exotic in origin, have established themselves in rivers. Brown trout was introduced from Europe for the first time in 1916 at Gilgit while Rainbow trout was introduced in NWFP in 1928. At present there are 32 farms and 10 hatcheries of trout in different districts of NWFP and Northern Areas and their estimated production is 162 tons per year. Among different factors affecting trout culture, nutrition is of prime importance as it contributes about 60-70 % of total cost of production. Earlier efforts to culture trout fish on conventional feed (50% wheat and 50% flour) resulted in poor growth, heavy mortalities and high cost of fish production. To manage trout culture on commercial basis, it was felt necessary to develop a low cost feed, based on locally available feed ingredients for accelerated fish growth, improved feed efficiency and to ensure a regular supply of feed throughout the year.
Based upon various studies, a low cost artificial diet was developed utilizing locally available ingredients. This feed gave better growth rate and had low feed conversion ratio. The feed primarily consisted of fish meal, meat meal, bone meal, dry milk, Vitamin-C and Cod liver oil. The feed provided a base for trout culture on commercial basis in Northern areas of Pakistan. This feed was further improved in 1993, using low cost feed ingredients of plant sources, thus reducing the cost of fish production. The new improved diet contains fish meal, soybean meal, cotton seed meal, sunflower meal and soybean oil.
This diet is currently prepared by the farmers themselves and is used by majority of the fish farmers in these areas.
Lone, K. P., (1982). Trout nutrition and feed formulation: Some basic facts. Progressive Farming, 2: 5-10.
Rab, A., S. A. Naveed and M. Afzal. (1990). Comparative performance of rainbow trout (Salmo gairdneri) fed on different rations. Sarhad J. Agric., 6: 631-635.