Estrus Synchronization and Gestation Rates in Cows under Two Estrus Induction Protocols

Abstract

Artificial insemination has been identified as a means to intensify local production and optimize the availability of proteins of animal origin in Africa. Therefore, some factors are seemed responsible to the failure of this application in rural area. This study was conducted from mid-March to June 2018, to evaluate the cow’s fertility after artificial insemination, progesterone and oxidative stress profiles according to the estrus synchronization protocols, breed, age and body condition score. 39 cows were concerned and divided into two groups. The first group was made of 9 adult cows (4 - 6 years old) with an average BCS of 4.44 + 0.55, a calving rank of 3 + 0.20 and 10 heifers (2 - 3 years old) with a BCS of 3.6 ± 0.52. The second group was constituted of 10 adult cows (4 - 6 years old) with an average calving rank of 2.7 ± 0.5 and BCS 4.2 ± 0.22 and 10 heifers (2 - 3 years old) with an average BCS of 3.8 ± 0.36. The induction of estrus was done using two protocols. The first one with CIDR + Cidirol-CIDR removal + Lutalyse + Cidirol-AI (protocol 1), which allows to obtain an estrus rate induction of 94.47% and a second one with CIDR + Cidirol-CIDR removal + Lutalyse-IA + Cidirol (protocol 2), which gave an estrus rate induction of 70% and was significantly lover from the first one (p < 0.05). The cow inseminations were done 48 ± 2 hours after estrus stimulation, with a fresh semen. Analysis have been done for blood progesterone level and oxidative stress indices, within the period of synchronization and after the insemination. The overall success rates of artificial insemination recorded was 69.23 0/0. According to the protocols, the first one gave a significantly higher gestation rate (80%) compared to the second one (50%). No significant effects of oxidative stress parameters on both synchronization and gestation rate were obtained between the protocols. Although, fertility has been affected by the breed, age and body condition score (p < 0.05). Thus, to complete these observations, recommendations were made to improve the knowledge of the impact of total oxidant capacity on the cow’s fertility during assisted reproductive treatments.