Effect of dietary omega-3 fatty acids on ovarian and insulin dynamic in Holstein dairy cows

The purposes of this study were to evaluate of ovarian and insulin dynamics in dairy cows fed omega-3 fatty acid source. Ten Holstein multiparous cows were selected and after adaptation period given diets containing palm oil (control) and fish oil (treatment) from day -40 to 60 after calving. The study carried to show the effect of omega-3 fatty acids on insulin resistance. Glucose tolerance tests were performed on days 14 and 42 after calving. The cows were synchronized using two injections of prostaglandin on days 20 and 34 after calving and consequently، ovarian dynamics were assessed. Blood samples were obtained on days -35، - 21، 0، 21، 42 and 62 days after calving. Experimental diets have not significant effect on the concentration of cholesterol، triglycerides، HDL cholesterol; however، omega-3 treatment significantly decreased LDL cholesterol levels. The results of the glucose tolerance test showed that omega-3 treatment improved insulin sensitivity. The number of small follicles (less than 6 mm) and medium (between 7 and 9 mm) and large (greater than 10 mm)، there were no significant differences between experimental groups. According to results we suggested that feeding omega-3 could improve insulin resistance in Holstein dairy cows.