Recent research estimates an average of 25 percent of cows have endometritis about four weeks before mating starts, but there is a large and unexplained variation in the prevalence of endometritis among herds.
Endometritis is commonly diagnosed using a Metricheck™ device to examine material recovered from the vagina. This material is then scored on a 1 to 5 scale, ranging from clear oestrus-like mucus to thick foul-smelling pus. A score of 2 or more is used to identify 'dirty' cows with metricheck-positive endometritis.
Herd metrichecking is commonly performed in two ways:
- Whole-herd metrichecking; one test of the entire herd around a month before mating starts.
- Batch metrichecking; testing a new batch of cows every two to three weeks based on their calving dates. Typically, batch metrichecking starts about three to four weeks after the first cow calves. This continues until all cows have been checked once.
- By doing a whole-herd pre-mating metricheck as well, you will pick up any cows that may have been missed or did not respond to early treatments.
During metrichecking, positive cows can be drafted and treated by your veterinarian. Treating infected cows, usually with intra-uterine antibiotics, will improve reproductive performance, but the treatment takes time to work. Uterine infections should be treated at least four weeks before mating starts. This gives affected cows the best chance of getting in calf early in the mating period.
The most at-risk cows are generally those that had an assisted or difficult calving, retained foetal membranes, twins, a stillborn calf, vaginal discharge after calving, or an abortion. Endometritis is also more likely to occur in cows with a body condition score (BCS) of 4 or less at calving, cows with ketosis, or older cows.
But for some cows with endometritis there is no history of problems around calving. Therefore, whole-herd metrichecking is recommended, rather than just checking the ‘at-risk’ cows.
The best way to prevent endometritis is through effective management of the transition period, optimising BCS, and minimising the number of cows with diseases around calving.