Equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled Nelore (Bos indicus) cows

Two experiments were conducted to investigate the effects of equine chorionic gonadotropin (eCG) at progestin removal and gonadotropin-releasing hormone (GnRH) at timed artificial insemination (TAI) on ovarian follicular dynamics (Experiment 1) and pregnancy rates (Experiment 2) in suckled Nelore (B...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Sá Filho, M.F., Ayres, H., Ferreira, R.M., Marques, M.O., Reis, Erlei Melo, Silva, R.C.P., Rodrigues, C.A., Madureira, E.H., Bo, G.A., Baruselli, P.S.
Formato: Artículo PeerReviewed
Lenguaje:Español
Publicado: 2010
Materias:
R Medicina (General)
Acceso en línea:http://pa.bibdigital.ucc.edu.ar/4997/1/A_S%C3%A1%20Filho.pdf
Aporte de:
Producción Académica Universidad Católica de Córdoba (UCCor) de Universidad Católica de Córdoba
id I38-R144-4997
record_format dspace
spelling I38-R144-49972025-11-06T16:17:43Z http://pa.bibdigital.ucc.edu.ar/4997/ Equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled Nelore (Bos indicus) cows Sá Filho, M.F. Ayres, H. Ferreira, R.M. Marques, M.O. Reis, Erlei Melo Silva, R.C.P. Rodrigues, C.A. Madureira, E.H. Bo, G.A. Baruselli, P.S. R Medicina (General) Two experiments were conducted to investigate the effects of equine chorionic gonadotropin (eCG) at progestin removal and gonadotropin-releasing hormone (GnRH) at timed artificial insemination (TAI) on ovarian follicular dynamics (Experiment 1) and pregnancy rates (Experiment 2) in suckled Nelore (Bos indicus) cows. Both experiments were 2 × 2 factorials (eCG or No eCG, and GnRH or No GnRH), with identical treatments. In Experiment 1, 50 anestrous cows, 134.5 ± 2.3 d postpartum, received a 3 mg norgestomet ear implant sc, plus 3 mg norgestomet and 5 mg estradiol valerate im on Day 0. The implant was removed on Day 9, with TAI 54 h later. Cows received 400 IU eCG or no further treatment on Day 9 and GnRH (100 μg gonadorelin) or no further treatment at TAI. Treatment with eCG increased the growth rate of the largest follicle from Days 9 to 11 (means ± SEM, 1.53 ± 0.1 vs. 0.48 ± 0.1 mm/d; P < 0.0001), its diameter on Day 11 (11.4 ± 0.6 vs. 9.3 ± 0.7 mm; P = 0.03), as well as ovulation rate (80.8% vs. 50.0%, P = 0.02), whereas GnRH improved the synchrony of ovulation (72.0 ± 1.1 vs. 71.1 ± 2.0 h). In Experiment 2 (n = 599 cows, 40 to 120 d postpartum), pregnancy rates differed (P = 0.004) among groups (27.6%, 40.1%, 47.7%, and 55.7% for Control, GnRH, eCG, and eCG + GnRH groups). Both eCG and GnRH improved pregnancy rates (51.7% vs. 33.8%, P = 0.002; and 48.0% vs 37.6%, P = 0.02, respectively), although their effects were not additive (no significant interaction). In conclusion, eCG at norgestomet implant removal increased the growth rate of the largest follicle (LF) from implant removal to TAI, the diameter of the LF at TAI, and rates of ovulation and pregnancy rates. Furthermore, GnRH at TAI improved the synchrony of ovulations and pregnancy rates in postpartum Nelore cows treated with a norgestomet-based TAI protocol. 2010-12-31 Artículo PeerReviewed application/pdf spa http://pa.bibdigital.ucc.edu.ar/4997/1/A_S%C3%A1%20Filho.pdf Sá Filho, M.F., Ayres, H., Ferreira, R.M., Marques, M.O., Reis, Erlei Melo, Silva, R.C.P., Rodrigues, C.A., Madureira, E.H., Bo, G.A. and Baruselli, P.S. (2010) Equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled Nelore (Bos indicus) cows. Theriogenology, 73 (5). pp. 651-658. ISSN 0093691X info:eu-repo/semantics/altIdentifier/doi/10.1016/j.theriogenology.2009.11.004 Copy to clipboard
institution Universidad Católica de Córdoba
institution_str I-38
repository_str R-144
collection Producción Académica Universidad Católica de Córdoba (UCCor)
language Español
orig_language_str_mv spa
topic R Medicina (General)
spellingShingle R Medicina (General)
Sá Filho, M.F.
Ayres, H.
Ferreira, R.M.
Marques, M.O.
Reis, Erlei Melo
Silva, R.C.P.
Rodrigues, C.A.
Madureira, E.H.
Bo, G.A.
Baruselli, P.S.
Equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled Nelore (Bos indicus) cows
topic_facet R Medicina (General)
description Two experiments were conducted to investigate the effects of equine chorionic gonadotropin (eCG) at progestin removal and gonadotropin-releasing hormone (GnRH) at timed artificial insemination (TAI) on ovarian follicular dynamics (Experiment 1) and pregnancy rates (Experiment 2) in suckled Nelore (Bos indicus) cows. Both experiments were 2 × 2 factorials (eCG or No eCG, and GnRH or No GnRH), with identical treatments. In Experiment 1, 50 anestrous cows, 134.5 ± 2.3 d postpartum, received a 3 mg norgestomet ear implant sc, plus 3 mg norgestomet and 5 mg estradiol valerate im on Day 0. The implant was removed on Day 9, with TAI 54 h later. Cows received 400 IU eCG or no further treatment on Day 9 and GnRH (100 μg gonadorelin) or no further treatment at TAI. Treatment with eCG increased the growth rate of the largest follicle from Days 9 to 11 (means ± SEM, 1.53 ± 0.1 vs. 0.48 ± 0.1 mm/d; P < 0.0001), its diameter on Day 11 (11.4 ± 0.6 vs. 9.3 ± 0.7 mm; P = 0.03), as well as ovulation rate (80.8% vs. 50.0%, P = 0.02), whereas GnRH improved the synchrony of ovulation (72.0 ± 1.1 vs. 71.1 ± 2.0 h). In Experiment 2 (n = 599 cows, 40 to 120 d postpartum), pregnancy rates differed (P = 0.004) among groups (27.6%, 40.1%, 47.7%, and 55.7% for Control, GnRH, eCG, and eCG + GnRH groups). Both eCG and GnRH improved pregnancy rates (51.7% vs. 33.8%, P = 0.002; and 48.0% vs 37.6%, P = 0.02, respectively), although their effects were not additive (no significant interaction). In conclusion, eCG at norgestomet implant removal increased the growth rate of the largest follicle (LF) from implant removal to TAI, the diameter of the LF at TAI, and rates of ovulation and pregnancy rates. Furthermore, GnRH at TAI improved the synchrony of ovulations and pregnancy rates in postpartum Nelore cows treated with a norgestomet-based TAI protocol.
format Artículo
PeerReviewed
author Sá Filho, M.F.
Ayres, H.
Ferreira, R.M.
Marques, M.O.
Reis, Erlei Melo
Silva, R.C.P.
Rodrigues, C.A.
Madureira, E.H.
Bo, G.A.
Baruselli, P.S.
author_facet Sá Filho, M.F.
Ayres, H.
Ferreira, R.M.
Marques, M.O.
Reis, Erlei Melo
Silva, R.C.P.
Rodrigues, C.A.
Madureira, E.H.
Bo, G.A.
Baruselli, P.S.
author_sort Sá Filho, M.F.
title Equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled Nelore (Bos indicus) cows
title_short Equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled Nelore (Bos indicus) cows
title_full Equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled Nelore (Bos indicus) cows
title_fullStr Equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled Nelore (Bos indicus) cows
title_full_unstemmed Equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled Nelore (Bos indicus) cows
title_sort equine chorionic gonadotropin and gonadotropin-releasing hormone enhance fertility in a norgestomet-based, timed artificial insemination protocol in suckled nelore (bos indicus) cows
publishDate 2010
url http://pa.bibdigital.ucc.edu.ar/4997/1/A_S%C3%A1%20Filho.pdf
work_keys_str_mv AT safilhomf equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
AT ayresh equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
AT ferreirarm equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
AT marquesmo equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
AT reiserleimelo equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
AT silvarcp equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
AT rodriguesca equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
AT madureiraeh equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
AT boga equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
AT barusellips equinechorionicgonadotropinandgonadotropinreleasinghormoneenhancefertilityinanorgestometbasedtimedartificialinseminationprotocolinsucklednelorebosindicuscows
_version_ 1848831221461680128

Ejemplares similares