[Heritability in the incidence of rudimentary teats in milk cows of the Bohemian spotted breed].

The set of 2,230 dairy cows was studied for genotype influence on the occurrence of rudimentary teats in the dairy cows of Bohemian Spotted breed. In the studied population 57.62% cows had rudimentary teats. Out of this percentage, 45.23% of animals had only one small teat, 50.43% cows had two small teats and 4.34% had more than two rudimentary teats. The estimation of rudimentary teat heritability was carried out by the method of daughter regression to dams in 185 pairs. The calculated heritability coefficient was medium high (h2 = 0.56 +/- 0.15). As found out further, the dams having rudimentary teats had by 20% higher proportion of daughters with rudimentary teats than the dams without rudimentary teats. This relationship is statistically highly significant. The interrelationship between the dams and daughters as to the occurrence of one or two rudimentary teats was statistically insignificant. By means of the analysis of variance in the groups of half-sisters after 49 sires (the average number of animals per group amounted to 45), the intracorrelation coefficient was determined and used for the calculation of the heritability coefficient h2 = 0.26 +/- 0.07.