Assessment of non-genetic parameters of the racing performances of Arabian and Thoroughbred horses in Algeria
From 1995 to 2007, flat racing data was collected for Thoroughbred and Arabian horses in Algeria. Non-genetic factors affecting racing performances have been identified and quantified using linear models. Performances are represented through the earnings and the rankings. Three traits were used: two earnings traits [the logarithm of annual virtual earnings (LAEV) and the logarithm of average annual virtual earnings per start (LAEV/S)], and one rank trait (the ranking transformed and normalised by application of the “performance rate” procedure, PERF). The results showed significant positive correlations (p < 0.001) between the three traits in the two breeds, showing that the measurements quantify similar - although different - aptitudes. The effects of sex, age, year of the performance and the interactions between age and sex and between age and year of the race turned out to be significant (p < 0.05) for the three traits LAEV, LAEV/S and PERF for the Arabian horses. However, for Thoroughbreds, the sex effect was only significant for the PERF trait and an interaction between the age and year of the performance was the only significant interaction (p < 0.001) for the LAEV trait. The effects of these non-genetic factors will be used to correct the raw measures in a future genetic evaluation.
Key words: Earnings, non-genetic factors, flat racing, race-horses, rankings, Algeria.