Lack of association between calf morbidity and subsequent first lactation milk production in 25 New York Holstein herds.

The association of owner-diagnosed calfhood diseases with first lactation milk production was evaluated using data collected prospectively for 728 heifers from 25 New York dairy herds. Cows diagnosed with one or more occurrences of dullness, respiratory disease, or scours within 90 d of birth had first lactation milk production that was similar to that of unaffected herdmates. Estimates for the effects of dullness, respiratory disease, and scours on second test milk production were -1.0, 1.0, and .4 kg/d, respectively (adjusted for season and age at calving, times milked per day, study month on birth, sire PTA for milk production, and the other two calfhood diseases). Estimates for the effects on 305-day mature equivalent production were -139, 123, and 158 kg for dullness, respiratory disease, and scours, respectively (adjusted for study month of birth, sire PTA for milk production, and the other two calfhood diseases). These results were based on data of heifers that were selected as replacements and remained in the herd long enough to have milk production recorded. There was no significant detrimental effect of owner-diagnosed calfhood disease on first lactation milk production, but affected heifers had higher mortality before calving and were less likely to enter the milking herd.