An investigation on the sperm quality of rainbow trout (Oncorhynchus mykiss) fed with diets suplemented N-3 series fatty acids

In this study, the effect of dietary supplementation with n-3 series essential fatty acids on sperm quality (volume, density, motility rate, motility time and pH of sperm, and total sperm number) in rainbow trout (Oncorhynchus mykiss) were investigated. In addition, the condition factor, gonadosomatic index and hepatosomatic index of rainbow trout and chemical quality (fatty acids and cholestrol contents) of sperm were investigated too.For this purpose, experimental diets control, 1, 2 and 3 were prepared at the n-3 series essential fatty acids rates 1.18%, 0.20%, 2.20% and 3.19%, respectively. Crude protein (45%) and total energy (4619 kcal/kg) levels of experimental diets were equalized. The fish were hand fed to satiation three times in a day at 9±1 oC water temperature for 45 days.At the end of this study, the best results for the sperm quality parameters (volume, density, motility rate, motility time and total sperm number) were obtained from Trial 2 diet group that was followed by Trial 3 and control groups, respectively. Lowest results were obtained from Trial 1 diet group. It was determined not significant (P>0.05) differences between the gonadosomatic index values of fish in Control, D2 and D3 groups. Gonadosomatic index value for the Trial 1 group fish was significantly (P<0.05) lower than those obtained from control, Trial 2 and Trial 3 group fish. It was determined significant (P<0.05) differences between the all experimental groups for fatty acids and cholestrol contents of fish sperm. On the other hand, it was found not significant (P>0.05) differences between the experimental groups for pH values of fish spermUnder the light of this study, it is concluded that the diet of adult rainbow trout has to constitute 2.20% of n-3 series essential fatty acids for generating high number and quality of sperm.