effect of fish oil feeding on reproductive performance in zandi ram

previous studies have indicated that fish oil intake wi1l improve semen quality in some mammals and birds. the aim of this study was to investigate the effect of dietary fish oil on reproductive performance in ram. eight zandi rams were divided into two groups and fed either a control diet or a supplemented diet with fish oil. both of the diets were isocaloric and isonitrogenous and formulated according to afrc (1995). semen samples were weekly collected from september to december of 2007 by artificial vagina. semen characteristics were evaluated. reaction times,frequency of tail rasing and mounting, and testi cular circumference were recorded every two weeks. live weight was recorded every thee weeks. at the end of trial, blood samples were obtained and plasma concentrations of testostrone and cholesterol were determined. fish oil supplementation improved progressive motility of sperm, percentage of motile sperm, sperm concentrations, total sperm number and mounting frequency. there were no significant differences between two groups in testi cular circumference, body weight and blood parameters (p>0.005). semen volume,frequency of tail raising and reaction times were not affected by dietary treatment. the results suggested that feeding of fish oil could attenuate the decreased reproductive performance which induced by non breeding season during late autumn in zandi rams