Resumen

MENESES ARIAS, Graciela et al. Fertility in dairy cows treated in the early luteal phase with a reused progesterone-releasing intravaginal device. Veterinaria México OA [online]. 2022, vol.9, e1056.  Epub 29-Mayo-2023. ISSN 2448-6760.  https://doi.org/10.22201/fmvz.24486760el2022.1056.

In this study, we tested whether early luteal phase treatment with a previously used progesterone-releasing intravaginal device (DIV) increased conception rate (CR) in dairy cows. Two experiments were performed; in the first, progesterone concentrations were determined in cows treated with a reused DIV. Seven cows received PGF2α and a reused DIV was inserted for seven days. Blood samples were collected daily for progesterone determination. Progesterone increased from 0.42 ± 0.17 ng/mL (mean ± standard deviation) at DIV insertion to 1.99 ± 0.52 ng/mL at 24 h and 2.11 ± 0.40 ng/mL at 48 h after; during the treatment period, progesterone showed an average concentration of 1.4 ± 0.55 ng/mL. In the second experiment, 383 cows were randomly divided on day 4 post-insemination, into two treatment groups: DIV (n = 188), received a reused DIV, which was removed on day 14; Control (n = 195), did not receive DIV. Progesterone concentrations were determined in seven cows from each group. The CR was not affected by treatment [DIV (33.5 %) vs. Control (37.4 %); P > 0.05]. No interaction was observed between treatment and service number, parity, the type of postpartum (normal or pathological), body condition, or days in milk (P > 0.05). Progesterone concentrations were similar between treatments (P > 0.05). We conclude that the insertion of a reused DIV at early diestrus did not increase serum progesterone concentrations or conception rate in dairy cows.

Palabras llave : progesterone; intravaginal progesterone-releasing device; dairy cows; fertility.

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