A comprehensive analysis of perinatal mortality for Holsteins in the upper Midwest was recently completed. Results showed that the incidence of perinatal mortality or calf losses near birth has been increasing since 1985; from 9.5% in 1985 to 13.2% in 1996 for virgin heifers; 5.3 to 6.6% in multiparous cows over the same time period. Replacement value of calves lost to perinatal mortality in the United States is about $125.3 million per year.

Sufficient data exist to permit identification of those sires whose daughters have a higher than average incidence for perinatal mortality with the birth of their calves. Further research is in progress to more completely establish the mode of inheritance for perinatal mortality. Other quantitative traits associated with early calfhood diseases, e.g., gestation length, dystocia, and incidence of twins are being examined.