RT Journal Article
T1 Effects on Synchronization and Reproductive Efficiency of Delaying the Removal of the Intravaginal Progesterone Device by 24 h in the 5d Co-Synch Protocol in Heifers
A1 Fernandez Novo, Aitor
A1 Santos López, Sergio
A1 Pesantez Pacheco, Jose Luis
A1 Pérez Villalobos, Natividad
A1 De las Heras Molina, Ana
A1 González Martín, Juan Vicente
A1 Astiz, Susana
AB In beef herds, increasing animal welfare, improving reproductive performance and easing animal management are key goals in farm economics. We explored whether delaying the removal of the intravaginal progesterone device by 24 h in heifers synchronized with a 5d Co-synch 72-h protocol could improve reproductive efficiency of fixed-time artificial insemination (FTAI). In experiment 1, we examined the total synchronization rate (TSR) in cycling Holstein heifers. Heifers (13.4 ± 0.69 mo.) were randomly assigned to the standard 5d Co-synch 56-h protocol (5dCo56; n = 10), 5d Co-synch 72-h (5dCo72; n = 17), or the modified 5d Co-synch 72-h protocol, in which removal of the progesterone device was delayed by 24 h (6dCo48; n = 19). In experiment 2, 309 cycling beef heifers on 18 commercial farms were subjected to the 5d Co-synch 72-h or 6-d Co-synch 48-h protocol and conception rate (CR) studied. In experiment 1, the three protocols led no differences on TSRs of 80.0% (5dCo56), 88.2% (5dCo72), and 89.5% (6dCo48). In experiment 2, the CR from the beef heifers, observed during two consecutive reproductive seasons did not differ: 59.7% for 5dCo72 and 62.0% for 6dCo48 (p = 0.907). Therefore, delaying removal by 24 h provides satisfactory results without reducing reproductive efficiency of heifers.
PB MDPI
YR 2021
FD 2021
LK https://hdl.handle.net/20.500.14352/115889
UL https://hdl.handle.net/20.500.14352/115889
LA eng
NO Fernandez-Novo, A., Santos-Lopez, S., Pesantez-Pacheco, J. L., Pérez-Villalobos, N., Heras-Molina, A., Gonzalez-Martin, J. V., & Astiz, S. (2021). Effects on synchronization and reproductive efficiency of delaying the removal of the intravaginal progesterone device by 24 h in the 5d co-synch protocol in heifers. Animals, 11(3), 1-13. https://doi.org/10.3390/ANI11030849
NO Author Contributions Conceptualization:S.A. methodology, all authors; software, A.F.-N., S.S.-L., J.L.P.-P., N.P.-V., J.V.G.-M. and S.A.; validation, A.F.-N., N.P.-V. and S.A.; formal analysis, A.F.-N., S.S.-L., J.L.P.-P., N.P.-V., A.H.-M. and S.A.; investigation, A.F.-N. and S.A.; resources, A.F.-N., S.S.-L., N.P.-V. and S.A.; data curation, A.F.-N., S.S.-L., N.P.-V., A.H.-M., J.V.G.-M. and S.A.; writing—original draft preparation, A.F.-N., N.P.-V. and S.A.; writing—review and editing, all authors; visualization, A.F.-N. and S.A.; supervision, A.F.-N., N.P.-V. and S.A.; project administration, S.A.; funding acquisition, A.F.-N., S.S.-L. All authors have read and agreed to the published version of the manuscript
DS Docta Complutense
RD 7 abr 2025