MORPHOLOGY AND MORPHOMETRY OF OVARIAN FOLLICLES IN THE GOAT

Ovarian follicles in the goat were investigated qualitatively and quan titatively with the light microscope. A pair of ovaries contained an a verage of 35 092 primordial follicles. Antrum formation began when the granulosa was about six cell layers in thickness, and the zona pelluc ida was visible at this stage. The diameter of the oocyte and thicknes s of the zona pellucida increased significantly during follicular deve lopment, reaching an average of 119 mu m and 3.2 mu m, respectively, i n vesicular follicles greater than 2 mm, indicating that oocyte growth continues after antrum formation. The mean number of normal vesicular follicles was 10.67, and about twice that number were atretic. The ty pe of atresia seen was of the obliterative type with primary follicula r wall. degeneration. There were no significant differences in the num ber of vesicular follicles, either normal or atretic, in the various s tages investigated, but significant differences were seen between norm al and atretic follicles in size categories less than 3 mm. An analysi s of the dominant follicle in the various stages suggests the presence of at least two waves of follicular growth. Overall, the results indi cate that follicular morphology and activity are similar in goats and sheep. (C) 1997 Elsevier Science B.V.