Grading versus animal model evaluation in arctic fox (Alopex lagopus)

Coat and conformation traits (body size, colour type, colour purity, coat density, hair length, general appearance, total score) of 4306 arctic foxes bred on the Sniaty Fox Farm (Poland) in 1985-1998 were evaluated using the grading standard (based on the point scale) and the BLUP with a single-trait animal model. Pearson correlation coefficients between the trait scores and their estimated additive genetic effects were calculated within each year of the analysis. Moreover, Spearman rank correlation coefficients for 20 animals ranked highest according to the BLUP evaluation and their ranking based on the scores was estimated. Pearson correlation coefficients ranged from -0.128 to 0.970 (most often 0.7-0.8) indicating (with some exceptions in 1991, 1992 and 1998) that the trait scores are usually consistent with the corresponding estimates of additive genetic effects. In contrast, for each trait analysed Spearman rank correlation coefficient was significantly negative (ranging from -0.687 to -0.857, P less than or equal to 0.01) showing that the best animals according to the two methods of evaluation did not overlap, Negative and low annual genetic trends estimated for the analysed traits (ranging from -0.00041 to 0.02822 point/year) suggest that the conformation scores as selection criteria are not effective.