Determination Growth Parameters in Different Popullation of Specific Pathogen Free (SPF)Rainbow TroutBrood Stocksnc(orhynchus mykiss)

This study aimed to compare growth indices and production of rainbow trout breeders (Oncorhynchus mykiss) without any specific pathogens in various populations at the Fishery Research Center of Coldwater-Tonekabon. The project's implementation included collecting Pre-breeders were done in selected rainbow trout breeding centers (based on the approval of the Iranian Fisheries Organization and the Iranian Veterinary Organization) at the provinces of West Azerbaijan, Mazandaran, Kohgiluyeh and Barahi. In total, the rainbow trout (in the form of seven treatments and three replicates) were collected from seven farms in the above-mentioned provinces and cultured with a density of 10 kg / m2 in concrete ponds in accordance with the principles of biosecurity. Pre-breeders have been marked for growth traits in order to trace the economic traits of the growth. Biometry was done in different growth stages in order to measure biological parameters such as obesity coefficient (CF), specific growth rate (SGR), and calculate the relationship between length and weight. The feeding rate for three-year-old breeders was 2-3% of fish weight and three times a day. During the breeding period, all physical and chemical parameters of the water were monitored and evaluated in order to control the optimum growth conditions. Water change was also done 4-6 times a day to maintain the physical and chemical quality of water. The mean of the obesity index of rainbow trout among the seven farms at the end of the growth period indicated that the highest of the obesity coefficient in pre-breeders from the Genetic Research Center of Shahid Motahari Yasouj which was 1.67. The growth equations showed the highest coefficient b (3.15) in males fish from the field of Mr. Maroufi, which indicates that the growth is isometric. Since pre-breeders were in the same environmental conditions, the environmental variability resulting from changes in environmental conditions as well as the variance of interaction between genetics and the environment declined to zero. Obviously, in this case, the functional differences of growth indices among different populations are due to genetic function and genetic variance.