[Hereditary defects in cattle in relation to chromosome analysis]

In the cytogenetic study of karyotypes of breeding bulls and cows aimed at their health and at the hereditary defects in offspring the lymphocytes from the peripheral blood from the jugular vein were employed. On the basis of the percentual evaluation of numerical and structural deviations in karyotypes the following criteria were established: the animals with deviations up to 10%--Ist class, with deviations from 10 to 20%--IInd class, with deviations over 20%--IIIrd class. From 17 breeding bulls of the first group two were included in the Ist class, twelve in the IInd class and three in the IIIrd class. From the second group, two sires belonged to the IInd class and four to the IIIrd class. Both dairy cows (mothers) that delivered calves with lethal factors, as well as the leukosis-suffering mother with daughter, were included in the IIIrd class. The chromosome analyses are given in tables.