Growth of Graafian Follicles in Cows Following Luteolysis Induced by the Prostaglandin F2a Analogue, Cloprostenol

Abstract
The ovaries of six multiparous cows 6--8 years old were collected 49-71 h after injection of a synthetic prostaglandin F analogue (c1oprostenol) and serially sectioned. All follicles >0·4 mm in diameter were counted and measured. The number of normal follicles ranged from 46 to 360 per cow. Atresia was not seen in follicles of < 1 ·7 mm diameter. The number of. early atretic follicles ranged from 4 to 20 per cow.