The reproductive performance of Thoroughbred mares treated with intravaginal progesterone at the start of the breeding season.
Abstract: The objective of this study was to investigate the effects of intravaginal progesterone on the reproductive performance of transitional Thoroughbred mares on commercial stud farms. Two hundred twenty-seven (227) non-lactating transitional Thoroughbred mares aged between 4 and 18 y (mean 9.4 ± 3.2 y) located on three stud farms in the Waikato region of New Zealand were used in the study performed during four consecutive breeding seasons (2007-10). Mares were age-matched in pairs and either treated with an intravaginal progesterone releasing device (Cue-Mare, 1.72 g progesterone, 10% w/w) for up to 10 d (Treated; n = 126) or left untreated (Control; n = 101). In both groups, 1,667 iu of hCG was given IV when an ovarian follicle ≥35 mm was detected (in conjunction with estrous behavior) and each mare was bred by natural service. Treated mares were served earlier in the breeding season (mean ± SD interval to first service was 13.9 ± 3.0 vs 26.7 ± 13.2 d for Treated and Control groups, respectively; P < 0.001). In the Treated and Control groups, 95.2 and 42.6% of mares were served within the first 21 d of the season (P < 0.001). Treated mares conceived earlier in the breeding season (mean number of days to conception 37.5 ± 14.2 vs 50.8 ± 21.3 d, P = 0.01). There was no difference between groups in the first service pregnancy rates (53.9 and 50.5% for Treated and Control mares, P = 0.89). Treatment with an intravaginal device increased the number of mares conceiving by the end of the breeding season (91.3 vs 82.3% for Treated and Control groups, P = 0.04). Therefore, this treatment protocol appeared to offer a convenient, economical and reliable method for managing transitional mares on commercial Thoroughbred stud farms.
Copyright © 2012 Elsevier Inc. All rights reserved.
Publication Date: 2011-12-06 PubMed ID: 22153271DOI: 10.1016/j.theriogenology.2011.10.001Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research article investigates the impact of intravaginal progesterone on the reproductive performance of Thoroughbred mares at the beginning of the breeding season.
Objective of the Study
- The primary focus of the study was to examine the effects of intravaginal progesterone on the reproductive performance of non-lactating transitional Thoroughbred mares on commercial stud farms.
Study Design and Participants
- The study was carried out across four consecutive breeding seasons (2007-10).
- Three stud farms in the Waikato region of New Zealand were chosen for the study, with a total of 227 Thoroughbred mares aged between 4 and 18 years participating.
- The mares were age-matched in pairs, with one group treated with an intravaginal progesterone-releasing device (Treated; n = 126), and the other group left untreated (Control; n = 101).
Treatment and Breeding Protocol
- Treated mares received a progesterone-releasing device for up to 10 days, while Control mares were not treated with the device.
- All mares were given an intravenous application of 1,667 International Units of hCG (Human Chorionic Gonadotropin) when an ovarian follicle, measuring at least 35 mm, was detected along with signs of estrous behavior.
- Each mare was then bred via natural service.
Results of the Study
- Treated mares began mating earlier in the breeding season, with a noted difference in the mean interval to the first service between the treated and control groups.
- Significantly more treated mares were bred within the first 21 days of the season compared to the control group.
- Treated mares conceived earlier in the breeding season compared to the Control mares.
- No significant difference was observed between the first service pregnancy rates of the Treated and Control groups.
- By the end of the breeding season, a higher number of treated mares had conceived in comparison to the control group.
Conclusion of the Study
- The study concluded that the treatment protocol, involving the use of an intravaginal progesterone device, presents a convenient, economical, and reliable method for managing transitional mares on commercial Thoroughbred stud farms.
- The treatment was especially effective in facilitating early breeding and conception in the breeding season.
Cite This Article
APA
Hanlon DW, Firth EC.
(2011).
The reproductive performance of Thoroughbred mares treated with intravaginal progesterone at the start of the breeding season.
Theriogenology, 77(5), 952-958.
https://doi.org/10.1016/j.theriogenology.2011.10.001 Publication
Researcher Affiliations
- Matamata Veterinary Services, Ltd, 26 Tainui Street, Matamata, New Zealand. dhanlon@matavet.co.nz
MeSH Terms
- Administration, Intravaginal
- Animals
- Breeding / methods
- Chorionic Gonadotropin / administration & dosage
- Female
- Fertilization / drug effects
- Horses / physiology
- Male
- New Zealand
- Pregnancy
- Pregnancy Rate
- Progesterone / administration & dosage
- Reproduction / drug effects
- Reproduction / physiology
- Seasons
Citations
This article has been cited 3 times.- Bianchi CP, Bruno S, Videla Dorna I, Rodríguez E, Aba MA. Effect of short-term artificial light and transvaginal progesterone device on first ovulation in late transitional mares. J Equine Sci 2022 Apr;33(1):1-6.
- Segabinazzi LGTM, Andrade LRP Jr, Alvarenga MA, Dell'Aqua JA Jr, Canisso IF. Use of Intravaginal Progesterone-Releasing Device Results in Similar Pregnancy Rates and Losses to Long-Acting Progesterone to Synchronize Acyclic Embryo Recipient Mares. Vet Sci 2021 Sep 10;8(9).
- Khan IU, Khairullah AR, Khan AY, Rehman AU, Mustofa I. Strategic approaches to improve equine breeding and stud farm outcomes. Vet World 2025 Feb;18(2):311-328.
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