Genetics of racing performance in the Japanese Thoroughbred horse:

Abstract

The Japan Racing Association (JRA) operates 10 national racecourses with both turf and dirt tracks. JRA formulates the rules for horseracing; registers owners, colors, and horses using foal registration; and licenses all JRA trainers and jockeys. In 1990, at the 10 racecourses there were 288 racing days, 3,353 races, and some 38,397 horses. Horse breeding is concentrated in 7 locations with 93% of the Thoroughbreds foaled each year coming from Hokkaido. Thoroughbred flat racing comprise 92% of all races held. Two year olds race together and nearly 40% of their races are run at 1200 m. Some 39% of the three year olds races are at 1800 m. For 3 (and 4) year olds, the range in distances is from 1000 m to 3600 m. The average, over years, of the number of race records per race for 2 year olds is 10.0 and for 3 year olds and up is 11.3. The average for race records per horse for 2 year olds is 3.5 and for 3 year olds and up is 6.7. This average for horses raced per year for 2 year olds is 1,164 and 4,240 for 3 year olds and up. Horses raced per sire averaged over years was 4.6 for 2 year olds and 10.5 for the older ages. The linear regression of seconds per 100 m fit the average seconds reported for the several distances run almost perfectly with R(2) values greater than .99 for all horse ages on either turf or dirt. There is selection practiced as indicated by horse numbers registered and their numbers over ages for stallions and mares. Less than .2% of the horses raced are geldings. A high degree of control exists by JRA in horse stabling and distribution of racing by horses over racecourses. Jockeys are trained by JRA, ride at several race courses, and ride for many trainers. ZUSAMMENFASSUNG: Genetik der Rennleistung beim Japanischen Vollblut: I. Beschreibung der Daten Die "Japan Racing Association" (JRA) betreibt in ganz Japan zehn Pferderennbahnen sowohl mit Rasen- als auch mit Sandkursen. JRA legt die Regeln für Pferderennen fest, registriert die Eigentümer, Farben und Pferde mittels Fohlenregistrierung und vergibt die Lizenzen für alle JRA-Trainer und -Jockeys. Im Jahre 1990 verzeichneten die zehn Pferderennbahnen 288 Renntage, 3353 Rennen mit 38 397 Pferden; Pferdezucht ist an sieben Orten konzentriert, wobei 93% der Vollblutfohlen aus Hokkaido stammen. Bei 92% der veranstalteten Rennen handelt es sich um Nichthindernisrennen von Vollblutpferden. Dabei stehen die Zweijährigen im Wettbewerb, und fast 40% der Rennen gehen über 1200 m. Etwa 39% der Dreijährigen nehmen an Rennen über 1800 m teil. Bei den Dreijährigen (und Vierjährigen) liegen die Distanzen zwischen 1000 bis 3600 m. Der Durchschnitt der Zahl der Rennmeldungen über mehrere Jahre für die Zweijährigen beträgt 10,0 und für die dreijährigen und älteren Pferde 11,3. Der Durchschnitt der Rennmeldungen pro Pferd bei den Zweijährigen beträgt 3,5 und den dreijährigen und älteren Pferden 6,7. Durchschnittlich nehmen jährlich an Rennen 1164 zweijährige und 4240 dreijährige und ältere Pferde teil. Die durchschnittliche Zahl der Pferde über mehrere Jahre war 4,6 ...

Factors that affect whether Arabian horses have earnings during their first year of racing

“…The present study has showed that an early age at first start increases the odds of earning money during the first year of racing. Previous studies also reported that age was a significant factor in racing times (12), best racing times (13), and earnings (14). Moreover, other studies reported that early starts have a positive influence on racing careers (6,9,15).…”

Influence of Track Surface Condition on Racing Times of Thoroughbred Racehorses in Flat Races

“…The details of horse racing and the organization of Thoroughbred training and racing carried out by JRA have been reported elsewhere [2,7,11].…”

“…The data used in this study were extracted from the computerized information system and the racing calendar published by the JRA [2,11]. The relationship between racing time and track surface conditions was analyzed for 183,465 Thoroughbred racehorses (99,803 on turf courses and 83,662 on dirt courses) that ran in 16,765 flat races held at 10 racecourses (Sapporo, Hakodate, Fukushima, Niigata, Tokyo, Chukyo, Hanshin, Kokura, Nakayama, and Kyoto) belonging to the JRA between 2000 and 2004 ( Table 1).…”

“…Factors that affect the racing time of racehorses in flat races include the nature of training, programmer, purse [1], sex, age, weight carried, performance [2], type of course (dirt or turf), track surface condition, genetics, racing distance [3][4][5], number of runners, and the connectedness between the jockey and the horse [6]. It has been reported that track surface condition, notably hard tracks with less cushioning effect, can be a risk factor for racing injuries [7].…”

Epidemiology of racing injuries in Thoroughbred racehorses with special reference to bone fractures: Japanese experience from the 1980s to 2000s

“…In other words, this finding suggests that racecourse-related factors (extrinsic or environmental factors) may influence racing time. Factors affecting racing times in flat races on JRA racetracks were reported by Oki [ 84 , 85 , 86 , 87 ]. These include factors such as the nature of training, programmer, purse, gender, age, weight carried, prior race performance, type of course (dirt or turf), track surface condition, genetics, racing distance, number of starters, and the connection between the jockey and the horse [ 85 ].…”