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Este artículo se encuentra disponible en la página web de la revista en la siguiente URL: https://onlinelibrary.wiley.com/doi/abs/10.1111/rda.13317 Este es el pre-print del siguiente artículo: Martínez-Ros, P., Astiz, S., García-Roselló, E., Ríos-Abellán, A. & González-Bulnes, A. (2019). Onset of estrus and preovulatory LH surge and ovulatory efficiency in sheep after short-term treatments with progestagen-sponges and progesterone-CIDRs. Reproduction in Domestic Animals, vol. 54, n. 2 (feb.), pp. 408-411, que se ha publicado de forma definitiva en https://doi.org/10.1111/rda.13317 This is the pre-peer reviewed version of the following article: Martínez-Ros, P., Astiz, S., García-Roselló, E., Ríos-Abellán, A. & González-Bulnes, A. (2019). Onset of estrus and preovulatory LH surge and ovulatory efficiency in sheep after short-term treatments with progestagen-sponges and progesterone-CIDRs. Reproduction in Domestic Animals, vol. 54, n. 2 (feb.), pp. 408-411, which has been published in final form at https://doi.org/10.1111/rda.13317 The present study supports that short-term (7-days) protocols based on progestagen-impregnated sponges and progesterone-loaded CIDRs are equally effective to induce ovulatory response in sheep. There were no significant differences in the onset of estrus behavior (32.0±6.0 and 33.8±4.0h after device withdrawal for sponges and CIDRs, respectively; p > .05) and preovulatory LH discharge (5.1 ± 2.1 and 5.8 ± 3.3h after onset of estrus behavior for sponges and CIDRs, respectively; p > .05). These features are similar to previously described for classical long-term (12-14 days) treatments. Hence, short-term CIDR-based protocols may be implemented using the same time-intervals for insemination than sponge-based and long-term protocols. Preprint

The present study characterizes, for sheep, the occurrence and timing of the onset of estrus behavior and ovulation and the yields obtained (ovulation rate, progesterone secretion, and fertility) after Controlled Internal Drug Release (CIDR) insertion for five, six, seven, or fourteen days, with or without equine chorionic gonadotrophin (eCG) in ewes of the Segure&ntilde, a meat breed. All the treatments showed above 80% of females displaying estrus, but the onset of estrus was earlier and more synchronized when using eCG and, among groups with eCG, onset of estrus was earlier in the sheep treated for 14 days than in the short-term treatments (p &lt, 0.05 for all). Administration of eCG after either short- or long-term treatments assured the occurrence of fertile ovulations in all the animals. Conversely, ovulatory success without eCG was found to be dependent on treatment length, with a high percentage of animals ovulating after five days of treatment (83.3%) and very low percentages after treatment for six or seven days (40% and 20%, respectively). Ovulation rate and progesterone secretion were similar among animals ovulating, but ovulation failures predetermined the fertility yields obtained in response to the treatments. Hence, the best results were found after treatment for 14 days plus eCG, and for 5 days without eCG (83.3 for both, p &lt, 0.05 when compared to the other groups with different treatment lengths and with or without eCG).

Este artículo se encuentra disponible en la página web de la revista en la siguiente URL: https://www.sciencedirect.com/science/article/abs/pii/S0378432018306626?via%3Dihub This is the pre-peer reviewed version of the following article: Martinez-Ros, P., Astiz, S., Garcia-Rosello, E., Rios-Abellan, A. & Gonzalez-Bulnes, A. (2018). Effects of short-term intravaginal progestagens on the onset and features of estrus, preovulatory LH surge and ovulation in sheep. Animal Reproduction Science, vol. 197 (oct.), pp. 317-323, which has been published in final form at https://doi.org/10.1016/j.anireprosci.2018.08.046. Este es el pre-print del siguiente artículo: Martinez-Ros, P., Astiz, S., Garcia-Rosello, E., Rios-Abellan, A. & Gonzalez-Bulnes, A. (2018). Effects of short-term intravaginal progestagens on the onset and features of estrus, preovulatory LH surge and ovulation in sheep. Animal Reproduction Science, vol. 197 (oct.), pp. 317-323, que se ha publicado de forma definitiva en https://doi.org/10.1016/j.anireprosci.2018.08.046. In the present study, there was a comparison among classical long-term progestagen (fluorogestone acetate) protocols for synchronization of estrus and ovulation (14 days; group FGA14, n = 9 ewes) and short-term protocols based on 7 days of progestagen treatment plus a dose of prostaglandin F at either insertion (PG-FGA7, n = 11) or removal (FGA7-PG, n = 12). There were no significant differences in the ovulation rate and progesterone secretion among treatments. The FGA7-PG group, however, had a similar percentage of ewes expressing estrous behavior than the group FGA14 (90.9 and 100%, respectively, with a trend for a lesser percentage in the PG-FGA7 group, 63.6%) and about 90% of the ewes in the FGA7-PG group had the preovulatory surge release of LH 8 h after the onset of estrous behavior. These features may be related to a greater number of preovulatory follicles during growing phases (P < 0.05) and a greater plasma estradiol concentration (P < 0.05) in this group than in the classical 14-day group, which suggest these are more functional preovulatory follicles. In conclusion, therefore, the use of the FGA7-PG treatment may favor efficiency of progestagen-based protocols for reproductive management. Preprint