Comparison of some blood serum biochemical compositions and ovarian follicular fluid among different-sized follicles in Arab sheep

Folliculogenesis serves as maturation of the ovarian follicle, a densely packed shell of somatic cells that contains an immature oocyte. During folliculogenesis, follicular fluids containing growth factors, hormones and nutrients pave the way for oocyte growth and development. The present study was aimed to compare glucose, urea, cholesterol and triglyceride levels of follicular fluids in different sized follicles and serum of Arab sheep. The blood and ovaries samples of 30 slaughtered sheep were taken to be studied. Follicular fluid was taken in three set of small (less than 2mm), medium (2 to 4 mm) and large (up to 4mm) sizes. Concentrations of glucose, urea, cholesterol and triglyceride levels of ovary fluids in different sized follicles and serum were measured. Results showed that serum glucose and urea was more than three follicular classes significantly; however, glucose concentration among three classes did not significantly different. As follicle gets larger, urea and triglyceride levels were reduced. Serums cholesterol concentration was significantly more than small and medium sized follicles but there was no significant difference between large follicle and serum among others. Generally, results showed that ovaries follicles size associate with changes in serum glucose and cholesterol concentrations. Identification of essential biochemical substances for follicle growth and development is promising to improve developing oocyte quality and finally reproduction.