Efeito da Aplicação de Flunixin Meglumine Sobre a Taxa de Gestação de Ovelhas Inseminadas via Transcervical

Abstract

Background : : : : In livestock animals, which artificial insemination (AI) is widely spread, a healthy uterine environment is an important factor that should be taken into account for an adequate fertilization and establishment and development of pregnancy. The main limitation to spread the frozen semen insemination in sheep is the high costs of the laparoscopy AI and the difficulty of traversing the cervix. To overcome problems associated with transcervical artificial insemination, new techniques and instruments have been proposed. The manipulation of cervix during transcervical artificial insemination in sheep can lead to a local inflammatory reaction that releases inflammatory mediators, such as prostaglandins and cytokines, that either can negatively affect the uterine environment and consequently, the conception. In this regard, the injection of a non-steroidal anti-inflammatory (NSAI) at the moment of AI could reduce the secretion of inflammatory mediators, promoting a healthier uterine environment favorable to conception. The flunixin meglumine is a NSAI which reduces the synthesis of PGF 2 a by the inibition of the cyclooxigenase. The objective of this study was to evaluate the effect of flunixin meglumine (non-steroid antiinflammatory) injection on pregnancy rate of ewes inseminated by the transcervical technique. Materials, Methods & Results : In this experiment 69 pluriparous ewes were used, 29 in control group (CG) and 40 in flunixin meglumine group (FMG). The estrus detection was performed twice daily for 5 days. The ewes detected with paint in the low back were considered in estrus. The AI procedure was performed 8 hours after the estrus detection. At the AI time, the ewes were separated according to body condition score in two experimental groups. The ewes of the FM Group were injected with 1.1 mg/Kg of flunixin meglumine, im, 1 hour before the AI procedure. In order to locate the ostium, a vaginal speculum and a source of external light were used; whereas the fixation and traction of the ostium were performed with an Allis clamp, allowing the penetration of the semen applicator throw the vagina and cervix. The insemination procedure was performed 8 hours after estrous detection. There was no difference (P > 0.05) on the pregnancy rate between groups, whereas the Control group had 68.9% and the FM group had 60.0% of pregnancy. Discussion : The result demonstrates that the local inflammatory reaction caused by the traction of cervix was not detrimental to uterine environment and fertilization, since a high pregnancy rate was detected in both groups. Although the hypothesis of this study was not supported by the results, the high pregnancy rate detected in this experiment was higher than the results normally detected. Several studies have shown low pregnancy rates when transcervical artificial insemination with frozen semen is used associated to protocols of estrous synchronization. The flunixin meglumine did not improve the pregnancy rate, probably due to the insemination procedure adopted, since the traction of the cervix were performed gently, and consequently minimized the tissue damage. Thus, the inflammatory reaction may not have been sufficiently extensive as to lead to alteration of the uterine environment. These results suggested that flunixin meglumine injection did not influence the conception when was used prior to the transcervical insemination.