Potential role of maternal lineage in the thoroughbred breeding strategy.
Many studies have focused on identifying the genes or single nucleotide polymorphisms associated with the athletic ability of thoroughbreds, but few have considered differences in maternal and paternal heritability of athletic ability. Herein, we report on our association study of career race performances of 675 Australian thoroughbreds with their pedigrees. Racing performance data (prize money per start) were collected from the Bloodhound database. The performance of all horses was categorised as either poor or elite athletic achievement. Then, 675 foals were divided by their parents' performance (elite or poor) into four groups: (1) elite dams and elite sires; (2) elite dams and poor sires; (3) poor dams and elite sires; and (4) poor dams and poor sires. The performance of foals was then compared between the four groups. The results show that the heritability of race performance between dams and foals (r = 0.141, P < 0.001) is much higher than that between sires and foals (r = 0.035, P = 0.366), and that this difference is statistically significant (P < 0.05). We also examined the effect of the child-bearing age of dams and sires on the ratio of elite foals. We found a strong correlation between the number of elite foals and dams' child-bearing age (r = -0.105, P < 0.001), with the ratio of elite offspring reaching a high level between a child-bearing age of 8 and 11 years (?2 = 14.31, d.f. = 1, P < 0.001). These findings suggest that the maternal line may play an important role in the selective breeding of athletic performance in thoroughbreds.
Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Tianjin University of Sports, Tianjin, 300381, China.
Xiang
X
Lin
School of Health and Human Sciences, Southern Cross University, Lismore, NSW 2480, Australia.
Shi
S
Zhou
Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Tianjin University of Sports, Tianjin, 300381, China.|Corresponding authors. Emails.
Li
L
Wen
School of Health and Human Sciences, Southern Cross University, Lismore, NSW 2480, Australia.
Allan
A
Davie
College of Animal Sciences, Xinjiang Agricultural University, Urumuqi, 830052, China.|Corresponding authors. Emails.
Xinkui
X
Yao
College of Animal Sciences, Xinjiang Agricultural University, Urumuqi, 830052, China.
Wujun
W
Liu
Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, Tianjin University of Sports, Tianjin, 300381, China.
Yong
Y
Zhang
athletic performance; birth age; horse breeding; mitochondrial DNA