Genetic aspects of racing performance in Polish pure bred Arab horses. II. Genetic trends

The objective of this study was to estimate genetic trends in the Polish Arab horses population. Annual earnings and rank at finish in fiat races of Polish Arab horses from 1951 to 1993 were analysed with a BLUP animal model. The collected data included 2,234 records of 1,640 4- and 5-year old horses from 143 sires. Only races, in which horses of at least two mentioned age groups took part, were taken into consideration. The model included an individual additive genetic effect as random, the year of race, herd, sex, age, number of starts and the year of race X age effects as fixed effects. Genetic trends were estimated from differences between horses belonging to different age groups and racing in the same year. The annual genetic gains from 1951 to 1993 were 3.5% and 12.3% of the genetic standard deviation for the log of earnings and rank at finish, respectively. Although the main role in breeding Arab horses is played by beauty and exterior, small genetic progress in the log of earnings and rank at finish was obtained.