Dilatadores hormonais cervicais utilizados na inseminação artificial transcervical em substituição a inseminação artificial laparóscopica na espécie ovina

Abstract

The aim of this study was to evaluate alternatives to perform transcervical artificial insemination (AI) in ovine. A total of 114 ewes were divided in five groups (G) as follows: G1- transcervical AI without cervical dilator (n=23); G2- transcervical with application of 500UI of oxytocin intramuscular (IM) (n=23); G3- transcervical AI with application of 1 mg of estrogen IM (n=22); G4- transcervical AI with application of 0.0375mg of prostaglandin F2α (PGF2α) MI (n=23) and G5- AI by laparoscopy (n=23). Estrus was synchronized using intravaginal sponges with medroxiprogesteron acetate for six days and insemination was performed 50 h after sponge withdrawal with fresh diluted semen. AI (P<0.05) was performed in less time in Group 5 using laparoscopy ( average of 4`13``) compared to Groups 1, 2, 3 and 4 ( duration of 5`54``; 5`37``; 5`37`` and 5`27``, respectively). Pregnancy rate for Group 5 was 68.18%, which was higher (P<0.05) than the results observed for groups 1, 2, 3, and 4 (30.4%, 8.6%, 0.0% and 13.0%, respectively). There was no difference in cortisol plasma concentration among the groups after insemination, with an average of 29.95 ng/Ml. Insemination by laparoscopy was the most efficient method for presenting higher pregnancy rate, faster and without variation of stress than transcervical inseminations.