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Tropical animal health and production2025; 57(3); 124; doi: 10.1007/s11250-025-04369-9

Retinol and cholecalciferol affect buserelin-induced estrous in anestrous mares.

Abstract: In winter anestrous, prolonged melatonin secretion inhibits gonadotropin-releasing hormone (GnRH). However, synthetic GnRH analogues such as buserelin can stimulate follicular development. We aimed to investigate clinical relationship between retinol, cholecalciferol, and buserelin for inducing estrous in anestrous mares (Equus caballus). We used a total of twenty-one anestrous mares, randomly divided into three groups of seven animals. Group A received retinol, cholecalciferol, and buserelin; group B received buserelin; and group C was control. Groups A, B, and C had 71.42% (n = 5; 95% CI: 26.30%-96.56%), 28.57% (n = 2; 95% CI: 16.56%-73.70%), and 0% mares in estrous, respectively. A significantly greater number of group A mares exhibited estrous (P = 0.005) and higher ovarian follicular size (P = 0.001) compared to group C. Serum estrogen was significantly higher in group A compared to Group B (P = 0.03) and C mares (P = 0.001). In multiple correspondence analysis (MCA) factor map, treatment with retinol, cholecalciferol, and buserelin was clustered with estrous mares having serum estrogen levels > 40 pg/ml and follicular size > 30 mm. The variance explained by the first two dimensions of MCA was 87.83%. Supplementing with retinol and cholecalciferol improved the rate of buserelin-induced estrous in anestrous mares. Further research is necessary to determine underlying mechanisms.
© 2025. The Author(s).
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Publication Date: 2025-03-17 PubMed ID: 40095200PubMed Central: PMC11913942DOI: 10.1007/s11250-025-04369-9Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article discusses how retinol and cholecalciferol boost the effectiveness of a synthetic hormone (buserelin) in inducing estrous in mares that are anestrous, in other words, not in heat.

Objective and Methodology

  • The study aimed to explore the effect of retinol (Vitamin A), cholecalciferol (Vitamin D3), and buserelin (a synthetic hormone that stimulates follicular development) for inducing estrous in mares that are anestrous during winter. In the colder months, mares often enter an anestrous phase due to prolonged melatonin secretion that inhibits the release of the GnRH hormone required for reproduction.
  • In this experiment, a total of twenty-one anestrous mares were used, split randomly into three groups. Each group was treated differently: Group A received retinol, cholecalciferol, and buserelin, group B only received buserelin, and group C was the control group not receiving any treatment.

Results and Findings

  • After the administration of the treatments, the study found that 71.42% of mares in group A (treated with retinol, cholecalciferol, and buserelin) exhibited estrous. This was significantly higher than both Group B (28.57%) that received only buserelin, and Group C (0%) which was left untreated.
  • Furthermore, the mares in Group A showed significantly higher ovarian follicular size and higher serum estrogen levels compared to the mares in the other two groups. These findings suggest that retinol and cholecalciferol have a role in enhancing the effect of buserelin.
  • The research also conducted a multiple correspondence analysis (MCA), a statistical technique used to visualize and analyze categorical data. Based on this, the mares that received retinol, cholecalciferol, and buserelin were clustered with estrous mares having serum estrogen levels above 40 pg/ml and follicular size above 30 mm. This highlights the positive influence of retinol and cholecalciferol on buserelin-induced estrous.

Conclusion

  • The findings from the study confirm that supplementing retinol and cholecalciferol enhances the rate of buserelin-induced estrous in anestrous mares.
  • However, further research is required to understand the underlying mechanisms of how retinol and cholecalciferol work in conjunction with buserelin to cause these effects.

Cite This Article

APA
Bukhari SSUH, Urooj S. (2025). Retinol and cholecalciferol affect buserelin-induced estrous in anestrous mares. Trop Anim Health Prod, 57(3), 124. https://doi.org/10.1007/s11250-025-04369-9

Publication

Tropical animal health and production
ISSN: 1573-7438
NlmUniqueID: 1277355
Country: United States
Language: English
Volume: 57
Issue: 3
Pages: 124

Researcher Affiliations

Bukhari, Syed S U H
  • Department of Veterinary Clinical Sciences, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, 999077, SAR, China. habukhari2@cityu.edu.hk.
  • Centre for Animal Health and Welfare, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, 999077, SAR, China. habukhari2@cityu.edu.hk.
  • Department of Theriogenology, Faculty of Veterinary Science, University of Agriculture, Faisalabad, 38000, Pakistan. habukhari2@cityu.edu.hk.
Urooj, Sundas
  • Department of Clinical Medicine and Surgery, Faculty of Veterinary Science, University of Agriculture, Faisalabad, 38000, Pakistan.

MeSH Terms

  • Animals
  • Female
  • Horses / physiology
  • Cholecalciferol / pharmacology
  • Cholecalciferol / administration & dosage
  • Buserelin / pharmacology
  • Buserelin / administration & dosage
  • Vitamin A / pharmacology
  • Vitamin A / administration & dosage
  • Anestrus / drug effects
  • Estrus / drug effects
  • Ovarian Follicle / drug effects
  • Random Allocation

Conflict of Interest Statement

Declarations. Ethics approval: This research was approved by the Scrutiny Committee of the Faculty of Veterinary Science, University of Agriculture Faisalabad (UAF), Pakistan, and the Graduate Study Research Board (GSRB) of the UAF (No. 2012-ag-2622). The study is reported according to the CONSORT guidelines for animal research. Consent to participate: Only mares participated in this research, and informed consent was obtained from the equine stud farm before the start of the study. Competing interests: The authors declare no competing or conflict of interest.

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