RESUMO
Frequencies of alleles and genotypes of the PRNP gene in 65 Polish Red cows kept under a conservation programme and 52 randomly chosen cows of two Czech breeds: Czech Pied (42) and Black-and-White (10) were studied. All cows were at the age of 4 years or older. It was found that the frequency of allele 5 (5 copies of the octapeptide repeat) ranged from 0.11 (Polish Red) to 0.00 (Czech Black-and-White) whereas the frequency of allele 6 (6 copies of the octapeptide repeat) ranged from 1.00 (Czech Black and White) to 0.89 (Polish Red). The highest frequency was found for the homozygous genotype 6/6 (1.00 in Czech Black-and-White) and the lowest frequency was detected for the heterozygous genotype 6/5 (0.143). In the studied cows the genotype 5/5 was not found. The higher frequency of allele 5 in the native breeds and its lower frequency or lack of this allele in the populations intensively selected for high milk production may suggest that alleles of the PRNP gene may be associated with milk production.
RESUMO
Genetic parameters (heritability, genetic and phenotypic correlations) of chosen coat colour traits of golden fox were estimated. 1013 animals, born on the Sniaty fox farm (Poland) in 1985-1999 were evaluated. In 1993-1999 colour type was additionally assessed for 833 animals, by detailed evaluation of coat colour on the back and sides of the body, throat colour, belly colour and the amount of silver hair. The REML method was used to estimate genetic (co)variance components. Data were transformed using the probit transformation. Heritability estimates for coat traits were low (0.04 to 0.22). Values of most of the estimated genetic parameters (h2, rG, rP) were comparable to those frequently reported for other colour types of silver fox.
