PATH-ANALYSIS FOR 7 POSTPARTUM DISORDERS OF HOLSTEIN COWS

Path analysis and multiple logistic regression with an extrabinomial v ariation error term (to account for herd) were used to model seven pos tpartum clinical disorders of dairy cows and factors related to the ca lf. Data were from 7761 lactation records from 34 commercial herds in the vicinity of Cornell University. Stillbirth increased the odds of d eveloping metritis and retained placenta. The odds of developing dysto cia and mastitis were lower when the sex of the calf was female. Howev er, cows that twinned had increased odds of developing dystocia and re tained placenta. Dystocia was related to an increase in the odds of re tained placenta. Milk fever, dystocia, and ketosis each increased the odds of developing left-displaced abomasum. Postpartum periods with dy stocia, retained placenta, or ketosis had increased odds of metritis. Two interaction terms involved parity: stillbirth for milk fever and r etained placenta for ketosis. The extrabinomial variation error term c ontributed to the fit in all models.