Recurrence odds ratios for periparturient diseases and reproductive traits of dairy cows

The recurrence odds ratios were calculated for a number of periparturient diseases and reproductive traits from 1490 pairs of successive lactations in dairy cattle. Vulval discharge, oestrus not observed and mastitis diagnosed before service had summary recurrence ratios of 1.39, 1.37 and 1.49 respectively, all statistically significant at the 5% level. Retained foetal membranes and calf mortality had higher summary risk ratios of 1.84 and 1.76 respectively, but were not significant at the 5% level. Whilst the number of services per conception did have a recurrence ratio above 1, the result was not significant at the 5% level.