Tropicultura (Jan 2010)
Efficacité de la synchronisation des chaleurs et insémination artificielle chez le bovin Azawak: intérêt du profil de progestérone
Abstract
Efficiency of Estrous Synchronization and Artificial Insemination in Azawak Cows: Interest of the Progesterone Profile. For a few years, the sperm of selected Azawak bull has been used in artificial insemination (AI) on the local bovine races of Niger, to improve the potential of production. Two methods of estrous and ovulation synchronization are compared: vaginal spirals PRID (Progesterone Vaginal Intra Device) and intra muscular injection of GnRH (Gonadotropin Releasing Hormon). For this purpose, seven and six Azawak Females were successively used by treatment. AI were carried out twice at 56 h and 68 h for the PRID, and 20 h and 44 h for the GnRH, after stop of the treatment. Heats appearance was controlled by direct observation during the 7 days following the end of the treatment. Blood were carried out for ten females (5 of each batch) three times per day from J9 to J16, then once daily until J27, and finally at twice-weekly intervals during the 5 weeks which followed, in order to establish a profile of plasmatic progesterone by animal. In addition, a pregnant diagnosis was carried out per transrectal palpation, three months after AI. For each of the two treatments, three females expressed estrus, including two before the first AI, and the third later (1 and 5 days respectively for the PRID and GnRH). The increase of plasmatic progesterone rate of these two cows, occurred in the two days after the first AI, with a pregnant on both for the PRID, and two for GnRH. The three whose heats were not noted, were not pregnant in both cases, and had an increase in the plasmatic progesterone rate 3 and 8 days after the first AI respectively for the PRID and GnRH. In conclusion, we did not observe a difference in the answers of two treatments. Moreover, the females without estrus observed, were showed a normal cycle (by the progesterone profile) but with late ovulations that have not allowed fecundation. These results suggest us once more, to make the first IA as of the appearance of heats, and in addition, to inseminate only on heats observed.
