Avaliação de um dispositivo auxiliar de detecção de estro de retorno em vacas leiteiras mestiças

Abstract

An important factor in dairy herds is reproductive efficiency. Given this, several studies show that this factor is highly compromised by estrus detection. The objective of this work was to evaluate the efficiency of the Estrotect® estrus detection method, in the dairy cow production system where the experiment was carried out, after fixed-time artificial insemination (FTAI) in crossbred dairy cows. The device, which facilitates the identification of animals that have accepted mounting by changing the color of the rectangular sticky sticker, similar to a bill, acts in the identification of estrus. The study was carried out at the Glória Experimental Farm, at the Federal University of Uberlândia. From August 2021 to May 2022, 101 return estruses were evaluated after TAI performed in lactating cows over 45 days after calving. The cows were submitted to the following FTAI protocol: on day 0, they received a 1.0g progesterone intravaginal device and the application of 2 mg of estradiol benzoate intramuscularly (IM). On day 7, 25 mg of dinoprost tromethamine (IM) was applied. On day 9, 1 mg of estradiol cypionate (IM) was injected and withdrawn from the progesterone intravaginal device, and 48 hours later, all cows were timed inseminated. On the day of bonding, Estrotect® was fixed on the animal's hip region. Bonding was performed 10 days after TAI, where the cows received the Estrotect® device for detecting estrus return in cows that did not become pregnant after TAI. The animals identified in estrus by activation of the auxiliary device were re-inseminated and the pregnancy diagnosis was performed by transrectal ultrasonography between 28 and 35 days after insemination. In order to determine the efficiency of the auxiliary estrus detection device, in addition to the estrus return detection rate after FTAI, the conception rate after estrus return insemination was evaluated. Data were performed by frequency analysis and inserted in the present work. Of the total analyzed, it was observed that 4 cows lost their devices (3.96%), only 7 animals were detected with return heat (6.93%), 49 animals did not show return to heat (48.51%) and 41 animals were identified as pregnant (40.51%). The Estrotect® device did not help the system. However, the discussion pointed to the hypothesis that the failure to make the correct decision when activating the device led to the ineffectiveness of the device at the experiment site, causing an error in proving its functionality. It was then concluded that the device did not improve the system, which previously lacked efficient estrus identification.