hCG is more effective than the GnRH agonist buserelin for inducing the first ovulation of the breeding season in mares.
horse
induction of ovulation
mares
spring transition
Journal
Equine veterinary journal
ISSN: 2042-3306
Titre abrégé: Equine Vet J
Pays: United States
ID NLM: 0173320
Informations de publication
Date de publication:
Mar 2022
Mar 2022
Historique:
revised:
15
02
2021
received:
15
04
2020
accepted:
03
04
2021
pubmed:
23
4
2021
medline:
10
2
2022
entrez:
22
4
2021
Statut:
ppublish
Résumé
Human Chorionic Gonadotropin (hCG) and Gonadotropin Releasing Hormone agonists (GnRHa) are routinely used to induce ovulation in mares. However, GnRHa efficacy in transitional mares has been suggested to be low. The aims of this study were as follows: (a) to compare the efficacy of hCG and GnRHa in inducing the first ovulation of the breeding season and (b) to evaluate the correlation between ovulatory response, uterine oedema and teasing score at the time of treatment during the early or late transitional phase. Randomised controlled superiority trial. Mares in winter anoestrus were treated with sulpiride when at least two follicles reached a diameter of 25 mm. The day after the follicle reached 35 mm in diameter, mares in oestrus were treated with GnRHa buserelin (N = 29) or hCG (N = 33) and checked daily for ovulation. More mares (30/33, 90.1%) ovulated when the first ovulation after winter anoestrus was induced with hCG, than with GnRHa, (11/29, 38.0%) (P = .0001). Ovulation rate was lower in mares that did not show uterine oedema and full acceptance of the teaser stallion for at least three days before the treatment (32/41, 78% vs 9/21, 42.9%) P = .01. Plasma LH and oestrogen concentrations were not performed. These results demonstrate that hCG was more effective than GnRHa for inducing ovulation in the first cycle after winter anoestrus. Uterine oedema and behavioural signs of oestrus, for at least three days before the treatment, were predictors for a positive response to ovulation induction.
Sections du résumé
BACKGROUND
BACKGROUND
Human Chorionic Gonadotropin (hCG) and Gonadotropin Releasing Hormone agonists (GnRHa) are routinely used to induce ovulation in mares. However, GnRHa efficacy in transitional mares has been suggested to be low.
OBJECTIVES
OBJECTIVE
The aims of this study were as follows: (a) to compare the efficacy of hCG and GnRHa in inducing the first ovulation of the breeding season and (b) to evaluate the correlation between ovulatory response, uterine oedema and teasing score at the time of treatment during the early or late transitional phase.
STUDY DESIGN
METHODS
Randomised controlled superiority trial.
METHODS
METHODS
Mares in winter anoestrus were treated with sulpiride when at least two follicles reached a diameter of 25 mm. The day after the follicle reached 35 mm in diameter, mares in oestrus were treated with GnRHa buserelin (N = 29) or hCG (N = 33) and checked daily for ovulation.
RESULTS
RESULTS
More mares (30/33, 90.1%) ovulated when the first ovulation after winter anoestrus was induced with hCG, than with GnRHa, (11/29, 38.0%) (P = .0001). Ovulation rate was lower in mares that did not show uterine oedema and full acceptance of the teaser stallion for at least three days before the treatment (32/41, 78% vs 9/21, 42.9%) P = .01.
MAIN LIMITATIONS
CONCLUSIONS
Plasma LH and oestrogen concentrations were not performed.
CONCLUSIONS
CONCLUSIONS
These results demonstrate that hCG was more effective than GnRHa for inducing ovulation in the first cycle after winter anoestrus. Uterine oedema and behavioural signs of oestrus, for at least three days before the treatment, were predictors for a positive response to ovulation induction.
Identifiants
pubmed: 33884659
doi: 10.1111/evj.13455
pmc: PMC9291952
doi:
Substances chimiques
Chorionic Gonadotropin
0
Gonadotropin-Releasing Hormone
33515-09-2
Buserelin
PXW8U3YXDV
Types de publication
Journal Article
Randomized Controlled Trial, Veterinary
Langues
eng
Sous-ensembles de citation
IM
Pagination
306-311Subventions
Organisme : University of Pisa
ID : PRA_2018_7
Informations de copyright
© 2021 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
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