The effect of ovarian follicular size and estrous cycle on IGF-1, insulin and glucose levels of follicular fluid and blood serum in Khuzestan hybrid cattle

Folliculogenesis is the important process in the female reproduction. During the follicular development، follicular fluid with growth factor، hormones and various nutrients، provides the conditions for growth and maturation of oocyte. The present study was performed to evaluation the IGF-1، insulin and glucose concentrations in ovarian follicular fluid of different sized follicles and blood serum during follicular and luteal phases of estrous cycle in hybrid cattle. The blood samples and ovaries of 20 slaughtered cattle (10 animals in follicular and others in luteal phases of estrous cycle) were studied. In laboratory، the follicular fluid was aspirated from small (6-9 mm) and large (≥10 mm) follicles. The concentrations of IGF-1، insulin and glucose in follicular fluids and blood serum were determined. The follicular fluid and serum levels of IGF-1 in follicular fluid was significantly (p0. 05). But، the serum level of insulin in follicular phase was significantly higher than that in luteal phase (P0. 05). However، in follicular phase، the concentration of blood serum insulin was significantly (p0. 05). In general، the results showed that IGF-1، insulin and glucose in follicular fluid and blood serum of cattle depending on the stage of the sexual cycle and follicular development is changing.