Abstract
A bio-economic model was created to simulate production of an average Finnish blue fox farm. The studied traits were pelt quality, pelt size, pelt color clarity, litter size, pregnancy (barren or non-barren), and felicity (includes both aborting and females losing all pups before pups are 3 weeks). Marginal economic values of traits were estimated by the numeric approximation of the partial derivate of the profit function with respect to those traits. Economic weights of traits were obtained by multiplying the marginal economic values by genetic standard deviations. Felicity, pregnancy, and litter size had the highest economic weights (26.80, 19.74, and 18.36 EUR/σa, respectively). Economic weights of pelt quality, length, and color clarity were 7.17, 5.24, and 0.33 EUR/σa, respectively. Changes in production environment (feed and price, improvement in fertility) had only minor effect on relative economic weights. Generally, an unfavorable change in environmental variables increases the relative weight of pelt quality.
Acknowledgements
We wish to thank Kerstin Smeds, M.Sci.Agr., and Tuula Dahlman, PhD, for their valuable comments. This work has been supported by the Finnish Fur Breeders' Association.