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Factors affecting foal birth weight in Thoroughbred horses.
Abstract: Foaling data from 348 Thoroughbred foals born on a commercial stud were analysed to investigate interrelationships among mare age, parity, gestation length, foal sex, placental weight, and foal birth weight. Placental weight was positively correlated with foal birth weight up to a threshold of 6.5 kg; above this, placental weight was not significantly associated with foal birth weight. Placental weight was assessed, including the amniotic membranes and umbilical cord as well as the allantochorion. Using path analysis, parity was positively associated with foal birth weight both directly and through increased placental weights, but age was not directly related to foal birth weight. Over the range of gestation lengths observed, gestation length was not significantly associated with foal birth weight. We conclude that, in populations represented by this study population, either placental weights up to 6.5 kg are rate-limiting for foal birth weight or placental weight increases with foal birth weight up to this threshold. However, further increases in placental weight are not associated with additional increases in foal birth weight. The positive association between parity and foal birth weight is mediated through increased placental weight as well as other pathways. Age is not directly related to foal birth weight and gestation length is not strongly associated with foal birth weight.
Publication Date: 2008-11-05 PubMed ID: 18980778DOI: 10.1016/j.theriogenology.2008.09.041Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
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.
This study investigates the various factors that influence the birth weight of Thoroughbred foals. The research suggests that placental weight, up to a certain threshold, plays a significant role in determining foal birth weight. However, other factors like mare’s age and the length of gestation don’t significantly affect foal birth weight.
Research Methodology
- The research team analysed the data from 348 Thoroughbred foals born in a commercial stud.
- They studied several factors, including the age of the mare, how many times the mare had given birth (parity), the length of the gestation period, the sex of the foal, the weight of the placenta, and the birth weight of the foal.
- In addition to the main placental structure (the allantochorion), the researchers also considered the weight of the amniotic membranes and the umbilical cord in their analysis.
Key Findings
- The researchers found a positive correlation between the weight of the placenta and the birth weight of the foal up to a placental weight of 6.5 kg. Beyond this threshold, no significant connection was found.
- The number of times a mare had given birth (parity) was found to have a positive association with the birth weight of the foal, both directly and indirectly, via increased placental weight.
- The age of the mare, contrary to popular belief, was not found to have a direct impact on the birth weight of the foal.
- The length of the gestation period was found to have no significant influence on the birth weight of the foal over the range of lengths observed in the study.
Conclusion
- The study concluded that either placental weights up to 6.5 kg play a crucial role in determining the birth weight of the foal or the weight of the placenta increases with the foal’s birth weight up to this threshold.
- However, any further increase in placental weight beyond the 6.5 kg mark does not result in additional increases in foal birth weight.
- Furthermore, the positive association found between mare parity and the birth weight of the foal is mediated through increased placental weight as well as other unknown pathways.
- The researchers clarified that factors such as the mare’s age or the length of gestation do not directly and significantly affect the birth weight of the foal.
Cite This Article
APA
Elliott C, Morton J, Chopin J.
(2008).
Factors affecting foal birth weight in Thoroughbred horses.
Theriogenology, 71(4), 683-689.
https://doi.org/10.1016/j.theriogenology.2008.09.041 Publication
Researcher Affiliations
- Main Ridge Veterinary Clinic, 334 Main Creek Road, Main Ridge, Victoria 3928, Australia. chrisbvsc@gmail.com
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Birth Weight / physiology
- Cohort Studies
- Female
- Horses / physiology
- Male
- Organ Size
- Parity
- Placenta / anatomy & histology
- Pregnancy
- Retrospective Studies
- Sex Characteristics
Citations
This article has been cited 11 times.- Ali A, Derar DR, Alaeyeari AA, Alharbi YM. Fetometry in Arabian horses. Front Vet Sci 2025;12:1689769.
- Hemberg E, Morrell JM. Case Report: Diagnosis and treatment of equine ascending placentitis: compilation of 17 case reports. Front Vet Sci 2025;12:1591452.
- Balogh O, Diab S, Parker A, de Sousa GC, Cecere JT, McCarter SJ, Sponenberg DP. Case report: Placental chorioadenoma in a primiparous pug dog. Front Vet Sci 2024;11:1505470.
- Hallman I, Karikoski N, Kareskoski M. The effects of obesity and insulin dysregulation on mare reproduction, pregnancy, and foal health: a review. Front Vet Sci 2023;10:1180622.
- Sharman P, Young AJ, Wilson AJ. Evidence of maternal and paternal age effects on speed in thoroughbred racehorses. R Soc Open Sci 2022 Oct;9(10):220691.
- Uchańska O, Ochota M, Eberhardt M, Niżański W. Dead or Alive? A Review of Perinatal Factors That Determine Canine Neonatal Viability. Animals (Basel) 2022 May 30;12(11).
- Neto da Silva AC, Costa AL, Teixeira A, Alpoim-Moreira J, Fernandes C, Fradinho MJ, Rebordão MR, Silva E, Ferreira da Silva J, Bliebernicht M, Alexandre-Pires G, Ferreira-Dias G. Collagen and Microvascularization in Placentas From Young and Older Mares. Front Vet Sci 2021;8:772658.
- Vieira GS, Paludo GR, Ramos AF, Pivato I, de Oliveira RA. Fetal development and blood hematological-biochemical parameters in Campeiro and Pantaneiro foals. Anim Reprod 2018 Aug 16;15(1):39-44.
- Robles M, Couturier-Tarrade A, Derisoud E, Geeverding A, Dubois C, Dahirel M, Aioun J, Prezelin A, Calvez J, Richard C, Wimel L, Chavatte-Palmer P. Effects of dietary arginine supplementation in pregnant mares on maternal metabolism, placental structure and function and foal growth. Sci Rep 2019 Apr 23;9(1):6461.
- Murase H, Miyazawa M, Harada T, Ozawa M, Sato F, Hada T. Aborted fetal sizes of Thoroughbred horses in Hidaka, Japan, between 2005 and 2015. J Equine Sci 2017;28(2):47-53.
- Peugnet P, Wimel L, Duchamp G, Sandersen C, Camous S, Guillaume D, Dahirel M, Dubois C, Jouneau L, Reigner F, Berthelot V, Chaffaux S, Tarrade A, Serteyn D, Chavatte-Palmer P. Enhanced or reduced fetal growth induced by embryo transfer into smaller or larger breeds alters post-natal growth and metabolism in pre-weaning horses. PLoS One 2014;9(7):e102044.
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