Changes In Ovarian Structures During The Estrous Cycle In Beef Females
An understanding of changing hormonal patterns and the normal growth and regression of ovarian structures is necessary to understand how to control onset of estrus. Estrus behavior in cows is stimulated by the production of estrogen in a large follicle. Follicles are the fluid-filled, balloon-like structures on the ovaries that contain the oocyte (egg). The large amount of estrogen produced by the follicle also stimulates a massive release of luteinizing hormone (LH). This LH surge generally occurs at the same time as the onset of standing estrus and stimulates the rupture of the large follicle (a process called ovulation) and release of the egg.