Table 1. Number of follicles and recovered oocytes in non-stimulated (control) and superstimulated Japanese Black cows.

		Non-stimulated	Superstimulated
No. of OPU sessions		7	6
No. of follicles at OPU
	Large follicles (> 8 mm)	1.1 ± 0.3 **	40.2 ± 4.2 **
	Medium follicles (≥ 5 to ≤ 8 mm)	3.3 ± 0.7 *	15.5 ± 6.4 *
	Small follicles (< 5 mm)	47.9 ± 8.9 **	7.5 ± 2.8 **
	Total follicles	52.3 ± 8.9	63.2 ± 12.5
No. of oocytes
	Normal oocytes (grade 1 to 3)	29.0 ± 4.1
	Abnormal oocytes (grade 4 and 5)	5.4 ± 1.4
	Oocytes with expanded cumulus cells		36.0 ± 7.0
	Oocytes with non-expanded cumulus cells		8.3 ± 1.7
	Degenerated oocytes		2.0 ± 1.4
	Total oocytes recovered	34.4 ± 3.7	46.3 ± 9.2
	Recovery rate of oocytes (%) a	69.8 ± 5.6	73.8 ± 2.9

Oocytes were collected from non-stimulated and superstimulated cows prior to ovum pick-up (OPU). Data are expressed as means ± SEM per head per OPU session. ^a The percentages of total number of oocytes recovered to total number of follicles was denoted. Asterisks indicate that values within the same row are significantly different (*, P < 0.05; **, P < 0.01).