Seasonal hydrology and its impact on buffalo artificial insemination strategies in the amazon region of northern Brazil.

This study aimed to verify how seasonal hydrology affects artificial insemination strategies in northern Brazil to promote better livestock management and ecosystem sustainability. A total of 1780 inseminations were analyzed, including 1590 fixed-time artificial inseminations (FTAI) and 190 conventional artificial inseminations (CAI) (AI in natural estrus without using hormones) conducted over ten years. Of these, 370 inseminations occurred during the flood season (January to May), 700 during the intermediate season (June to September), and 710 during the ebb season (October to January). The estrus synchronization protocols were utilized according the ovarian cyclicity of buffaloes, i.e.: Protocol I (Ovsynch), was used for cycling buffaloes; Protocol II (Ovsynch-P4); Protocol III (CL-synch), for the buffaloes with a mature corpus luteum (CL); Protocol IV (P4 + BE) + (PGF2α + eCG) + GnRH and Protocol V (P4 + VE) + (PGF2α + eCG) + BE were implemented for buffaloes in anestrus, with low body condition, or during unfavorable seasons. AI was performed using cryopreserved-thawed semen. Pregnancy diagnosis was performed using ultrasonography or rectal palpation between 45 and 90 days after insemination. A higher pregnancy rate was observed for the PI (66.87%) than for II (53.77%), III (52.41%), IV (53.35%) and V (33.17%). Regarding seasons, the overall pregnancy rate (53.14%) for FTAI was significantly higher (P < 0.05) than CAI (27.4%). During the season of Full tide, Intermediary and Ebb tide, the percentage of pregnancy rate for FTAI vs CAI was 48.28 vs 20.00, 47.77 vs 10.00 and 61.47 vs 41.00, respectively. The pregnancy rate was significantly higher during ebb tide for both FTAI/CAI than in other seasons. In conclusion, seasonal hydrology impacts the outcome of AI strategies in buffaloes in the Amazon region of northern Brazil. A suitable synchronization protocol can enhance buffalo fertility and improve agricultural practices.