Evaluation of pastel fox breeding results in poland - production traits

摘要

Material for study was females of common fox different color varieties maintained in 1978-1997, from which 4155 progenies with pastel fur were observed. In order to estimate the efficiency of selection, evaluation of genetic and phenotypic trends wereapplied. Phenotypic trends were estimated as changes of phenotypic trait mean values in time. The basis for genetic trends estimation in population studied was the solution for the birth year of an individual describing the changes of genetical qualityin tune. Calculations were made using software BLUPf90, applying multi-trait animal model. Selection differences for reproduction and conformation traits taken into account during selection were calculated to estimate the intensity of the process. They were accepted as differences between mean phenotypic value of a trait among young foxes chosen to general herd and mean phenotypic value of a trait for all young. On a base of results achieved, the conclusion was drawn that positive values of genetic trends for conformation traits and number of reared animals testify to proper direction of breeding work. However, their low values point out to low efficiency of selection. This can be a result of large number of traits considered during selection. For allinvestigated traits with exception of litter size at birth, an increasing tendency was found during the years under investigation which proves, the breeding work was conducted properly in this herd.