Reproductive Performance of Male Rainbow Trout Oncorhynchus mykiss (Walbaum, 1792) Feeding with Food from Two Different Manufacturers

Abstract

This study was carried out to compare the growth and development of testicles in rainbow trout, Oncorhynchus mykiss (Walbaum, 1792) at the Royal fish and Magazin Maprim fish farms using pellet fish feed of various manufacturers. Two groups with 30 individuals of the same age were examined. The males from the Royal fish farm were fed with Skretting feed while the Magazin Maprim fish farm used Coppens feed. Fish were fed twice a day at 5% body weight basis. Physicochemical parameters of water were within acceptable values for this species. The values of total length and total weight of the males from the Royal fish farm fed with Skretting feed showed a significant statistical difference compared to the males from the Magazin Maprim fish farm fed with Coppens feed. Also, mean weight of the testicles and gonadosomatic index of the males fed with Skretting feed did not show a statistically significant difference compared to the weight of the testicles and gonadosomatic indexof the males fed with Coppens feed. Histological assay of the testicles of rainbow trout subjected to experimental feeds showed a normal cell growth and spermatogenesis in both groups. The results indicate that there are differences in the growth of rainbow trout between the observed groups in favor of Skretting feed manufacturer, which should be taken into account when selecting the feed for a more productive farming.