Table 2.

Classification and characterization of bovine follicles [2, 27].

Follicle	No. of GC layers	No. of GC	Diameter of follicle (μm)	Diameter of oocyte (μm)	ZP	Inner theca
Primordial (type 1)	1	<10 flat	<40	30	No	No
Primary (type 2)	1–1.5	10–40 cuboidal	40–80	31	No	No
Small preantral (type 3)	2-3	41–100	81–130	49	No	No
Large preantral (type 4)	4–6	101–250	131–250	69	+	+
Small antral (type 5)	>6	>250	250–500	93	++	++