The research, developed in a swine production system, examined the effectivity of luteinizing hormone (LH) in ovulation induction. Twenty four sows compose the control group and tirthy two sows received intramuscular aplication of 600 IU of eCG (Novormon 5000®), 24 h after weaning and 5 mg of LH (Lutropin - V ®), 56 h after eCG injection (treated group). Oestrus were observed twice a day, the ovulation detected by transcutaneous ultrasonography and ovulation rate (OR) determined by corpora lutea counting. The weaning-to-estrus interval (WEI) were reduced (P=0,01) by treatment (87,4 vs 98,5 h). The ovulations occured among 32 and 48 h (37,25 ± 3,65) after LH and were diferent (P < 0,0001) of control (63,67 ± 20,22, range: 32 - 104 h). The OR of treatment was similar (P = 0,2) on the control (23,16 ± 12,19 vs 20,08 ± 5,19, respectively).
LH; Synchronization; Ovulation; Gonadotrophins; Sows
