Follicular Fluid Concentrations of Biochemical Metabolites and Trace Minerals in Relation to Ovarian Follicle Size in Dairy Cows.

In the present study, ovarian follicular fluid concentrations of trace elements and biochemical metabolites in relation to follicular size were investigated in dairy cows. Ovaries were recovered from 40 female adult Holstein Friesian cows 5–7 years of age with clinically normal reproductive tracts after slaughtering. The stage of the cycle in the cows slaughtered was diestrus determined post mortem. Visible follicles on the surface of the ovaries were classified, based on their diameter, into (i) small (3-5 mm), (ii) medium (6-9 mm) and (iii) large (10-20 mm) categories. Follicular fluid samples were analyzed for elements (iron, iodine, copper, manganese, zinc, cobalt, molybdenum and selenium) and biochemical metabolites (glucose, cholesterol, triglyceride, total protein, albumin, globulin, urea and creatinine). Results showed that concentrations of trace elements were different between follicles sized categories. Differences in follicular fluid concentrations of iodine and manganese between follicles sized categories were significant (p ≤ 0.05). In addition, differences in follicular fluid concentration of glucose and cholesterol between follicles sized categories (Small, Medium and large follicles) were significant (p ≤ 0.05). These results of the present study suggest that the levels of trace elements and biochemical metabolites composition in the follicular fluid were related to follicular size in dairy cows.