Early selection of leg conformation in Finnish blue fox (Vulpes lagopus)

The main aim of this research was to investigate the early selection, genetic associations and suitability of two leg conformation traits, carpal hyperlaxity (LAXITY) and valgus deformity (VALGUS), for introduction into the breeding scheme. Results showed that LAXITY1 occurred at an early age (5-14 weeks) in 44% of blue fox puppies. LAXITY1 had moderate heritability (0.20±0.06) and positive genetic correlation (0.40±0.28) with LAXITY2, which was assessed at the end of growth. The frequency of VALGUS was quite low, 6 to 7%, in the data. Also, the heritability was low, close to zero in VALGUS1 and 0.11±0.04 in VALGUS2. Genetic correlation between the two VALGUS traits was positive, even though the standard error was high (0.29±0.68). Obtained genetic parameters indicated that early selection has potential to improve carpal hyperlaxity of blue foxes. However, ideal evaluation and selection time point of valgus deformity is at later growth phase. Selection against VALGUS and LAXITY is highly recommended in order to maintain blue fox’s ability to move about. Animals with poor leg conformation should not be used for breeding. If more efficient selection is needed, the selection index and multiple-trait animal models can be applied in breeding for better leg conformation.