Analyze Diet
New Zealand veterinary journal2005; 53(2); 101-112; doi: 10.1080/00480169.2005.36487

Musculoskeletal responses of 2-year-old Thoroughbred horses to early training. 6. Bone parameters in the third metacarpal and third metatarsal bones.

Abstract: To determine the effect of a known training regimen on the size and mineral content of the third metacarpal (Mc3) and third metatarsal (Mt3) bones of 2-year-old Thoroughbred horses trained on racetracks. Methods: Mc3 and Mt3 of seven horses trained on grass and sand tracks were scanned at several sites using conventional quantitative and peripheral computed tomography (CT). Bone dimensions and density in the diaphysis and epiphysis were compared with those from seven untrained horses. Calcein label was injected in two clusters, during Weeks 9 and 12. The extent and rate of diaphyseal modelling was determined by confocal fluorescent microscopic examination of thin plane parallel sections of the mid-metacarpal region. Results: Volumetric bone mineral density (BMDv) of the epiphysis was markedly higher and of the diaphysis was slightly higher in trained compared with untrained horses, but greater bone size in the trained horses had the greatest effect on an index of bone strength. Active osteons, defined as Haversian systems containing calcein label, were fewer, of smaller diameter at the time of calcein injection, and had a greater bone apposition rate in trained than in untrained horses. Conclusions: Conventional training of 2-year-old Thoroughbred racehorses over a 13-week period had a significant effect on bone size, density and strength index when compared to untrained horses. Conclusions: Bone responded rapidly to early training. The data provide reference values and sites for use in longitudinal studies of commercial training regimens.
Publication Date: 2005-04-23 PubMed ID: 15846394DOI: 10.1080/00480169.2005.36487Google 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
  • Research Support
  • Non-U.S. Gov't

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 explores the impact of early training on the size and mineral content of specific bones in 2-year-old Thoroughbred horses. The findings suggest that a regular training regimen significantly affects bone size, density, and strength as compared to untrained horses, while also suggesting that bones respond quickly to early training.

Methodology

  • The researchers studied the third metacarpal (Mc3) and third metatarsal (Mt3) bones in seven 2-year-old Thoroughbred horses that were trained on grass and sand tracks.
  • These bones were scanned at various sites using conventional quantitative and peripheral computed tomography (CT).
  • Comparisons were made between the measurements of these bones from the trained horses and those from seven untrained horses.
  • The researchers also injected a calcein label during the 9th and 12th weeks of training to determine the extent and rate of diaphyseal modelling. This was observed under a confocal fluorescent microscope.

Results

  • The researchers found that trained horses had a significantly higher volumetric bone mineral density (BMDv) of the epiphysis compared to untrained horses. The diaphysis also showed slightly higher BMDv in trained horses.
  • The size of the bone was found to be larger in trained horses, which had a major impact on the bone’s strength index.
  • Additionally, trained horses had fewer active osteons (Haversian systems containing calcein label), smaller osteon diameters at the time of calcein injection, and a greater bone apposition rate compared to untrained horses.

Conclusion

  • The researchers concluded that a regular training regimen for 2-year-old Thoroughbred racehorses over a 13-week period significantly increased bone size, density, and strength index compared to untrained horses.
  • The bones responded relatively quickly to this early training, providing valuable data for reference in future studies related to commercial training regimens.

Cite This Article

APA
Firth EC, Rogers CW, Doube M, Jopson NB. (2005). Musculoskeletal responses of 2-year-old Thoroughbred horses to early training. 6. Bone parameters in the third metacarpal and third metatarsal bones. N Z Vet J, 53(2), 101-112. https://doi.org/10.1080/00480169.2005.36487

Publication

ISSN: 0048-0169
NlmUniqueID: 0021406
Country: England
Language: English
Volume: 53
Issue: 2
Pages: 101-112

Researcher Affiliations

Firth, E C
  • Massey Equine, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand. e.c.firth@massey.ac.nz
Rogers, C W
    Doube, M
      Jopson, N B

        MeSH Terms

        • Animals
        • Bone Density / physiology
        • Female
        • Horses / anatomy & histology
        • Horses / physiology
        • Metacarpal Bones / anatomy & histology
        • Metacarpal Bones / physiology
        • Metatarsal Bones / anatomy & histology
        • Metatarsal Bones / physiology
        • Microscopy, Confocal / veterinary
        • Physical Conditioning, Animal / physiology
        • Reference Values
        • Tomography, X-Ray Computed / veterinary

        Citations

        This article has been cited 22 times.
        1. Noordwijk KJ, Chen L, Ruspi BD, Schurer S, Papa B, Fasanello DC, McDonough SP, Palmer SE, Porter IR, Basran PS, Donnelly E, Reesink HL. Metacarpophalangeal Joint Pathology and Bone Mineral Density Increase with Exercise but Not with Incidence of Proximal Sesamoid Bone Fracture in Thoroughbred Racehorses. Animals (Basel) 2023 Feb 24;13(5).
          doi: 10.3390/ani13050827pubmed: 36899684google scholar: lookup
        2. Doube M. Closing cones create conical lamellae in secondary osteonal bone. R Soc Open Sci 2022 Aug;9(8):220712.
          doi: 10.1098/rsos.220712pubmed: 35958092google scholar: lookup
        3. Palmer AL, Rogers CW, Stafford KJ, Gal A, Bolwell CF. Risk-Factors for Soft-Tissue Injuries, Lacerations and Fractures During Racing in Greyhounds in New Zealand. Front Vet Sci 2021;8:737146.
          doi: 10.3389/fvets.2021.737146pubmed: 34926634google scholar: lookup
        4. Morrice-West AV, Hitchens PL, Walmsley EA, Wong ASM, Whitton RC. Association of Thoroughbred Racehorse Workloads and Rest Practices with Trainer Success. Animals (Basel) 2021 Nov 1;11(11).
          doi: 10.3390/ani11113130pubmed: 34827862google scholar: lookup
        5. Crawford KL, Finnane A, Greer RM, Barnes TS, Phillips CJC, Woldeyohannes SM, Bishop EL, Perkins NR, Ahern BJ. Survival Analysis of Training Methodologies and Other Risk Factors for Musculoskeletal Injury in 2-Year-Old Thoroughbred Racehorses in Queensland, Australia. Front Vet Sci 2021;8:698298.
          doi: 10.3389/fvets.2021.698298pubmed: 34796223google scholar: lookup
        6. Crawford KL, Finnane A, Greer RM, Phillips CJC, Bishop EL, Woldeyohannes SM, Perkins NR, Ahern BJ. A Prospective Study of Training Methods for Two-Year-Old Thoroughbred Racehorses in Queensland, Australia, and Analysis of the Differences in Training Methods between Trainers of Varying Stable Sizes. Animals (Basel) 2021 Mar 25;11(4).
          doi: 10.3390/ani11040928pubmed: 33805873google scholar: lookup
        7. Crawford KL, Finnane A, Phillips CJC, Greer RM, Woldeyohannes SM, Perkins NR, Kidd LJ, Ahern BJ. The Risk Factors for Musculoskeletal Injuries in Thoroughbred Racehorses in Queensland, Australia: How These Vary for Two-Year-Old and Older Horses and with Type of Injury. Animals (Basel) 2021 Jan 21;11(2).
          doi: 10.3390/ani11020270pubmed: 33494508google scholar: lookup
        8. Mellor DJ, Beausoleil NJ, Littlewood KE, McLean AN, McGreevy PD, Jones B, Wilkins C. The 2020 Five Domains Model: Including Human-Animal Interactions in Assessments of Animal Welfare. Animals (Basel) 2020 Oct 14;10(10).
          doi: 10.3390/ani10101870pubmed: 33066335google scholar: lookup
        9. Doube M, Felder AA, Chua MY, Lodhia K, Kłosowski MM, Hutchinson JR, Shefelbine SJ. Limb bone scaling in hopping macropods and quadrupedal artiodactyls. R Soc Open Sci 2018 Oct;5(10):180152.
          doi: 10.1098/rsos.180152pubmed: 30473802google scholar: lookup
        10. Liley H, Zhang J, Firth EC, Fernandez JW, Besier TF. Statistical modeling of the equine third metacarpal bone incorporating morphology and bone mineral density. PLoS One 2018;13(6):e0194406.
          doi: 10.1371/journal.pone.0194406pubmed: 29874224google scholar: lookup
        11. Rosanowski SM, Chang YM, Stirk AJ, Verheyen KLP. Risk factors for race-day fatality in flat racing Thoroughbreds in Great Britain (2000 to 2013). PLoS One 2018;13(3):e0194299.
          doi: 10.1371/journal.pone.0194299pubmed: 29561898google scholar: lookup
        12. Martig S, Hitchens PL, Stevenson MA, Whitton RC. Subchondral bone morphology in the metacarpus of racehorses in training changes with distance from the articular surface but not with age. J Anat 2018 Jun;232(6):919-930.
          doi: 10.1111/joa.12794pubmed: 29446086google scholar: lookup
        13. Yamada K, Sato F, Higuchi T, Nishihara K, Kayano M, Sasaki N, Nambo Y. Experimental investigation of bone mineral density in Thoroughbreds using quantitative computed tomography. J Equine Sci 2015;26(3):81-7.
          doi: 10.1294/jes.26.81pubmed: 26435681google scholar: lookup
        14. Turley SM, Thambyah A, Riggs CM, Firth EC, Broom ND. Microstructural changes in cartilage and bone related to repetitive overloading in an equine athlete model. J Anat 2014 Jun;224(6):647-58.
          doi: 10.1111/joa.12177pubmed: 24689513google scholar: lookup
        15. Whitton RC, Mirams M, Mackie EJ, Anderson GA, Seeman E. Exercise-induced inhibition of remodelling is focally offset with fatigue fracture in racehorses. Osteoporos Int 2013 Jul;24(7):2043-8.
          doi: 10.1007/s00198-013-2291-zpubmed: 23371360google scholar: lookup
        16. Doube M, Wiktorowicz-Conroy A, Christiansen P, Hutchinson JR, Shefelbine S. Three-dimensional geometric analysis of felid limb bone allometry. PLoS One 2009;4(3):e4742.
          doi: 10.1371/journal.pone.0004742pubmed: 19270749google scholar: lookup
        17. Firth EC. The response of bone, articular cartilage and tendon to exercise in the horse. J Anat 2006 Apr;208(4):513-26.
        18. Pan M, Malekipour F, Pivonka P, Morrice-West AV, Flegg JA, Whitton RC, Hitchens PL. A mathematical model of metacarpal subchondral bone adaptation, microdamage and repair in racehorses. J R Soc Interface 2025 Oct;22(231):20250297.
          doi: 10.1098/rsif.2025.0297pubmed: 41027486google scholar: lookup
        19. Son JK, De Paz P, Kim J, Sanaei R, Ryu S, Bailey S, Davies HMS. The change in third metacarpal mid-diaphyseal radiographic dimensions in Thoroughbred foals through growth. Equine Vet J 2025 Nov;57(6):1600-1611.
          doi: 10.1111/evj.14484pubmed: 39967447google scholar: lookup
        20. Son JK, De Paz P, Kim J, Sanaei R, Seungho R, Bailey S, Davies HMS. Distal forelimb radiographic bone morphology in Thoroughbred foals during the first 10 months post-partum. Part 1: Carpus. Vet Med Sci 2024 Jul;10(4):e31539.
          doi: 10.1002/vms3.1539pubmed: 39018065google scholar: lookup
        21. Hewitt-Dedman CL, Kershaw LE, Schwarz T, Del-Pozo J, Duncan J, Daniel CR, Cillán-García E, Pressanto MC, Taylor SE. Preliminary study of proton magnetic resonance spectroscopy to assess bone marrow adiposity in the third metacarpus or metatarsus in Thoroughbred racehorses. Equine Vet J 2025 Mar;57(2):471-479.
          doi: 10.1111/evj.14086pubmed: 38699829google scholar: lookup
        22. Costa da Silva RG, Sun TC, Mishra AP, Boyde A, Doube M, Riggs CM. Intracortical remodelling increases in highly loaded bone after exercise cessation. J Anat 2024 Mar;244(3):424-437.
          doi: 10.1111/joa.13969pubmed: 37953410google scholar: lookup