Management factors related to Salmonella shedding by dairy heifers.

In a national survey of dairy operations with > or = 30 milking cows, fecal samples from 6861 preweaned dairy heifer calves on 1063 operations were tested for Salmonella. One hundred forty-five (2.1%) of the fecal samples from 79 (7.4%) of the farms tested positive for Salmonella. A multivariate logistic regression model revealed that medicated milk replacer and hay fed to dairy heifers from 24 h of age until weaning were associated with a reduced risk of Salmonella sheddings, as was calving in an individual animal area within a building.