M. Seidgar - National Artemia Research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Urmia, Iran
M. Hafezieh - Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Tehran, Iran
A. Nekoueifard - National Artemia Research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Urmia, Iran
K. Ghara - Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Tehran, Iran
Z. Alizadeh Osalou - National Artemia Research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Urmia, Iran
F. Mohebbi - National Artemia Research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Urmia, Iran
M.M. Rezaei - Management of Fisheries and Aquatics Organization of Jihad – Agriculture of Markazi Province, Iran

This research was aimed to investigate the effect of mechanization on the growth and nutritional indices of dual-purpose rainbow trout farms in the Markazi province (Iran). ۵ cities with high production capacity and pools numbers were selected in cooperation and according to the provincial fisheries. The experts were sent to the farms to prepare necessary documents, complete the questionnaire regarding the existing and active mechanization equipment and the technologies used, the production in the farm, the type of food consumed, the factory producing the feed, type of feeding (automatic, manual), use of feed dispensers, the same size of fish to avoid competition and the dominance of larger fish during feeding, the condition and method of food storage. Growth and nutrition indicators of farms were determined. some mechanization equipments of farms included as aeration tower (۹۰%), drum filter (۲۳.۳۳%), Feed storage equipped with a fan (۳۰%), pallet in the feed store (۶۶.۶۷%), sediment pool (۵۳.۳۳%) and grading (۷۶.۶۷%), respectively.  Mechanization and the type of food had effect on the growth process of fish, and the improvement of nutritional management, the use of resources more efficiently with the optimization and correct selection of the type, amount, method of feeding increases the economic productivity of dual-purpose rainbow trout culture ponds in the Markazi province. This study showed that various variables such as the amount of production, quantity and quality of food, health management, density, fish weight, implementing fishing patterns, construction of a sediment collection pool, fish grading, proper storage in optimal and hygienic conditions on pallets, installation of aerators and installation mesh in the windows in the feed store, periodic testing of the physico-chemical and microbial parameters of the water, can be effective in the farm's performance.

Mechanization, Agricultural dual-purpose fields, Feeding, Markazi Province