Effect of advancing age on the reproductive performance of Japanese Thoroughbred broodmares.
Abstract: Many studies have reported that advancing age in broodmares has a negative impact on the reproductive performance of horses. However, although the ages at first and last mating vary among broodmares, it is unknown how this variation affects the correlation between age and reproductive performance in mares. Here, in order to examine the effects of the ages at first and last mating, we analyzed all recorded mating events for Thoroughbreds in Japan from 1997 to 2017. We found that the live foal birth rate of mares with a younger age at first mating indeed declined at an earlier age than those with an older age at first mating and that the number of years since the first mating also contributes to the decline in the birth rate. We also found that the live foal birth rate and mean earnings of the produced foals are much higher for mares with an older age at last mating compared with mares with a younger age at last mating. Our results should aid breeders in assessing the value of broodmares and designing breeding strategies.
©2021 The Japanese Society of Equine Science.
Publication Date: 2021-06-18 PubMed ID: 34220269PubMed Central: PMC8240526DOI: 10.1294/jes.32.31Google Scholar: Lookup
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- Journal Article
Summary
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The research investigates the correlation between the reproductive performance of Japanese Thoroughbred broodmares and their age, particularly the age at first and last mating. The study found that mares that start mating earlier tend to experience a decline in live foal birth rates earlier, and the number of years since first mating contributes to this decline. Mares that mate at an older age have higher live foal birth rates and mean earnings from their foals.
Objective and Methodology
- The objective of the research was to determine the effect of mares’ age at first and last mating on the reproductive performance of Japanese Thoroughbred broodmares. The study aimed to help breeders in assessing the value of broodmares and in devising breeding strategies.
- The researchers analyzed all recorded mating events for Thoroughbreds in Japan from 1997 to 2017 to fulfill the aim of the study.
Findings
- The study found that the live foal birth rates of mares with a younger age at first mating declined at an earlier age compared to those mares who started mating at an older age.
- It was also discovered that the number of years since the first mating plays a significant part in the decline of the birth rate. This implies that the longer the mating period, the more likely the foal birth rate will decrease.
- Mares that mate at an older age have higher live foal birth rates and mean earnings from their foals. This finding indicates that mares mating later in life perform better reproductively and contribute more economically than those that start mating at a younger age.
Implications and Applications
- These findings should aid breeders in assessing the value of broodmares and in designing efficient breeding strategies. Understanding the performance patterns can help optimize breeding schedules and maximize foal output and revenue.
- The age-performance correlation identified in the study can provide breeders with valuable insights for estimating the reproductive lifespan and profitability of a broodmare, enabling informed decision-making regarding the mare’s breeding schedule and overall management.
Cite This Article
APA
Fawcett JA, Innan H, Tsuchiya T, Sato F.
(2021).
Effect of advancing age on the reproductive performance of Japanese Thoroughbred broodmares.
J Equine Sci, 32(2), 31-37.
https://doi.org/10.1294/jes.32.31 Publication
Researcher Affiliations
- RIKEN iTHEMS, Saitama 351-0198, Japan.
- SOKENDAI (The Graduate University for Advanced Studies), Kanagawa 240-0193, Japan.
- Northern Farm Tenei, Fukushima 962-0516, Japan.
- Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan.
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