[Occurrence and economic importance of congenital hernia in German Fleckvich calves]

The frequency of congenital hernia was investigated in German Fleckvieh calves being driven up for sale on livestock markets for breeding and fattening calves in Miesbach and Traunstein. Data were collected on 77 livestock auctions in the years 1996 and 1997. Altogether 53,105 calves were examined and 1.8% of these calves showed a congenital umbilical hernia. The incidence of umbilical hernia was significantly influenced by the sex of the calf, the occurrence of multiple births, the market place/market date, the sire and the sire line. Red Holstein blood proportion, lactation number, duration of pregnancy and 305 day milk performance were not of significant importance. Herd milk level did not influence the incidence of congenital umbilical hernia, however, herdmate averages for calves differed significantly in their incidence. The average difference of the market price between male calves affected by congenital umbilical hernia and not affected male calves amounted to 75 DM, in female calves, however, only to 38 DM. The risk, that a congenital umbilical hernia is not closing within an age of 15 months, depends on the width of the hernial opening in the newborn calf. An opening of 4 cm and more has only a healing chance of 50% and less. However, negative effects on fattening and carcass traits could be not found. The genetic influence on congenital umbilical hernia was obvious. The analyses indicated that the incidence of congenital umbilical hernia observed could not be explained by one autosomal recessive gene locus, but it seemed much more likely that more than one gene locus is involved or a mixed multifactorial monogenic mode of inheritance may be the underlying genetic mechanism. Breeders should be aware of the implications of congenital hernias and thus, congenital hernia should get more attention in the selection process of young sires.