Risk factors for congenital umbilical hernia in German Fleckvieh.

Risk factors for congenital umbilical hernias were investigated in German Fleckvieh calves up for sale at livestock markets. Data from 53,105 calves were collected from 77 livestock auctions in 1996 and 1997. The overall incidence of congenital umbilical hernia was 1.8%. A significant influence on incidence was exerted by the sex of the calf, the occurrence of multiple births, the market place/market date, the sire and the sire line. The proportion of Red Holstein blood in the calf, the dam's lactation number, gestation length, 305 day milk performance and the herd milk level were not significant factors. Herdmate averages for calves differed significantly in their incidence. Heritability estimates on the liability scale for congenital umbilical hernia were about 0.4 and progeny groups of sires at risk for congenital umbilical hernia were in the range 0.1% to 14.2%. The segregation pattern could not be explained either by an autosomal recessive or by an autosomal dominant monogenic model. It seems likely that more than one gene locus is involved in the underlying genetic mechanism. Breeders should be aware of the genetic implications of congenital umbilical hernias.