Fertility in Dairy Herds - Advanced Part 5 : The impact of mastitis and lameness on fertility

These effects occur in cows with mild and moderate mastitis as well as those with severe mastitis; in cows with Gram negative pathogens (e.g. E. coli) and Gram positive ones (e.g. Staph. aureus); in cows which get mastitis before breeding and in cows which get mastitis afterwards. In fact for the last comparison, some studies have shown that cows which get mastitis after they have been bred for the first time have poorer fertility than cows which get mastitis which occurs (and is cured) before they are inseminated. There are many ways in which mastitis may be producing its impact on fertility. Probably the most important is through inflammation; inflammation produces prostaglandins, one of which, PGF2α, is important in the regulation of the cow's oestrus cycle. So reducing the inflammation due to mastitis could be a valuable way of improving the fertility of cows with mastitis. Indeed, a recent study looking at treating mild to moderate mastitis with meloxicam (a potent anti-inflammatory) as well as antibiotics showed that, in a seasonal system, treatment with meloxicam significantly reduced the proportion of cattle that were culled because of failure to get pregnant, while on non-seasonal farms treatment with meloxicam improved conception rate and the proportion of cows pregnant within 120 days of calving.