Congenital disorders in the cattle population of the Czech Republic

The aim of the paper was to analyse congenital disorders in the Czech cattle population in 1986-2001. The offspring of 474 sires - 215 Czech Simmental, 236 Holstein, and 23 beef - were diagnosed with congenital disorders which were unevenly distributed because only 18 occurred in the progeny of 10 and more sires, in contrast to 88 occurring in the progeny of I sire only. Umbilical hernia was the most frequently noted disorder, and 136 sires fathered progeny with limb anomalies. The most frequent gestational accident was schistosomus reflexus, the results suggesting a familial burden. Three sires fathering offspring with the afflicted spinal column and limbs were heterozygous for Complex Vertebral Malformation (CVM) though they had not been reported as such. Foetal defects and stillbirth were quite frequent, and the calves affected were fathered by 56 sires. In rare disorders with a low incidence, an accurate genetic analysis or even simple discrimination between inherited and acquired defects is problematic. It would be our recommendation that those sires with a higher incidence of defects among their offspring should be disqualified from fathering stock bulls, or culled.