A candidate-SNP retrospective cohort study for fracture risk in Japanese Thoroughbred racehorses |
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Authors: | T. Tozaki K. Kusano Y. Ishikawa A. Kushiro M. Nomura M. Kikuchi H. Kakoi K. Hirota T. Miyake E. W. Hill S. Nagata |
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Affiliation: | 1. Genetic Analysis Department, Laboratory of Racing Chemistry, 1731-2 Tsurutamachi, Utsunomiya, Tochigi, 320-0851 Japan;2. Equine Department, Japan Racing Association, Minato, Tokyo, 106-8401 Japan;3. Racehorse Hospital Ritto Training Center, Japan Racing Association, Ritto, Shiga, 520-3005 Japan;4. Racehorse Hospital Miho Training Center, Japan Racing Association, Miho, Ibaraki, 300-0493 Japan;5. Comparative Agricultural Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502 Japan;6. School of Agriculture and Food Science, University College Dublin, Dublin, 4 Ireland Plusvital Ltd, The Highline, Dun Laoghaire Industrial Estate, Pottery Road, Dun Laoghaire, Co Dublin, Ireland |
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Abstract: | Fractures are medical conditions that compromise the athletic potential of horses and/or the safety of jockeys. Therefore, the reduction of fracture risk is an important horse and human welfare issue. The present study used molecular genetic approaches to determine the effect of genetic risk for fracture at four candidate SNPs spanning the myostatin (MSTN) gene on horse chromosome 18. Among the 3706 Japanese Thoroughbred racehorses, 1089 (29.4%) had experienced fractures in their athletic life, indicating the common occurrence of this injury in Thoroughbreds. In the case/control association study, fractures of the carpus (carpal bones and distal radius) were statistically associated with g.65809482T/C (P = 1.17 x 10-8), g.65868604G/T (P = 2.66 x 10-9), and g.66493737C/T (P = 6.41 x 10-8). In the retrospective cohort study using 1710 racehorses born in 2000, the relative risk (RR) was highest for male horses at g.65868604G/T, based on the dominant allele risk model (RR = 2.251, 95% confidence interval 1.407–3.604, P = 0.00041), and for female horses at g.65868604G/T, based on the recessive allele risk model (RR = 2.313, 95% confidence interval 1.380–3.877, P = 0.00163). Considering the association of these SNPs with racing performance traits such as speed, these genotypes may affect the occurrence of carpus fractures in Japanese Thoroughbred racehorses as a consequence of the non-genetic influence of the genotype on the distance and/or intensity of racing and training. The genetic information presented here may contribute to the development of strategic training programs and racing plans for racehorses that improve their health and welfare. |
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Keywords: | chip fracture heritability horse horseracing MSTN |
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