Induced ovulation of the first postpartum dominant follicle in beef suckler cows using a GnRH analogue

摘要: There is a low incidence of ovulation the first dominant follicle that develops in early postpartum period beef suckler cows, which prolongs interval from calving to ovulation. The objective this study was determine whether single injection GnRH analogue would ovulate follicle. Limousin x Friesian cows were assigned at parturition, over two years (16 year 1; 19 2), one three treatments: (1) untreated (control; n = 12), (2) (20 micrograms buserelin i.m.) administered growing-plateau phase (GnRH-G; 12) and (3) declining (GnRH-D; 11). From day 8 or 9 post partum, ovaries each cow examined daily by ultrasound time Blood samples collected for progesterone measurement confirm 2 duration oestrous cycle. mean (+/- SEM) number days parturition development 11.0 +/- 0.3, 10.3 0.5 10.1 0.7 treatments 1-3, respectively (P > 0.05). proportion ovulating higher < 0.05) following treatment (12 12 7 10; GnRH-G GnRH-D, respectively) than with controls (2 12).(ABSTRACT TRUNCATED AT 250 WORDS)