Association of parturient hypocalcemia with eight periparturient disorders in Holstein cows

The association between parturient hypocalcemia and 8 periparturient disorders (dystocia, retained fetal placenta, metritis, left displaced abomasum, foot problems, ketosis, mastitis, and coliform mastitis) was evaluated in 33 Holstein dairy herds (2,190 cows) that calved from March 1981 through February 1982. There were highly significant (P less than 0.0001) associations between parturient hypocalcemia and dystocia, retained fetal placenta, ketosis, and mastitis. The odds ratios (multiplicative increases in occurrence) for these associations were 6.5, 3.2, 8.9, and 8.1, respectively. There was a significantly (P less than 0.03) association between parturient paresis and coliform mastitis (odds ratio, 9.0). There was a tendency for association with left displaced abomasum (odds ratio, 3.4; P less than 0.06).