Observed and expected combined effects of metritis and other postpartum diseases on time to conception and rate of conception failure in first lactation cows in Iran

Previous observational studies have produced strong evidence that metritis alone has an impact on reproductive performance in dairy cows; but few studies have examined the combined effect of metritis and other postpartum diseases on reproduction performance in dairy cows. Information on the combined effects of postpartum diseases on fertility in dairy cows can have practical herd-health management implications. The objective of the study reported here was to examine the observed and expected combined effects of metritis and other postpartum diseases (retained fetal membranes (RFM), clinical hypocalcemia, left displaced abomasum, clinical mastitis, lameness) on time to conception and rate of conception failure in first-lactation cows up to 150 days postpartum. The study was conducted on two commercial dairy herds in Iran. Median number of days to conception was higher in 30 cows affected with metritis and RFM (90 days), compared to 287 healthy cows (57 days), 16 cows affected with RFM alone (60 days) or 44 cows affected with metritis alone (60 days), after controlling for herd and calving month (p