Infections of the uterus after calving
At calving around 90% of cattle have a bacterial contamination of the inside of the uterus. In many cows the immune system will clear the contamination. Some cows however will develop either metritis or endometritis. Metritis is a significant infection of the uterus that makes the cow sick. Endometritis is an infection of the lining of the uterus that doesn’t make the cow sick but is often long-term and reduces the chance of the cow becoming pregnant. We often refer to cows with endometritis as “dirty cows”
Studies suggest that around 17% of cows in New Zealand herds will have endometritis. Some herds will be higher than this. In these cows the bacteria, pus, and inflammation associated with the infection can have a major impact on their reproductive performance come mating time. Cows with endometritis will take longer to cycle, longer to conceive and ultimately will have a higher empty rate, all of which cost you money and will negatively impact next seasons mating.
How do you tell which cows are dirty and how many of them there are in your herd? By Metrichecking.
Metrichecking, for those that don’t know, is using a metal rod with a rubber cup on the end, inserting it into the cow’s vagina and pulling a sample of whatever is present back out and checking it for the presence of pus. Cows that have pus present are then treated with an antibiotic, via a pipette, directly into the uterus.
Metrichecking can be used in several different ways.
Some people like to draft out their at-risk cows (assisted calvings, twins, retained foetal membranes, skinny cows, sick cows, down cows) and only get those cows metrichecked. This method risks missing 30% of the total number of dirty cows in the herd.
A better method is to metricheck the whole herd. Herd metrichecking can be applied in one of two ways. The first is to do one whole herd metricheck around a month before mating starts. The second approach is to do multiple metrichecks beginning around three weeks after the first cow calves and then repeating them around every three weeks so that the vet shows up and checks the herd about three times (referred to as batch metrichecking).
A New Zealand study found that cows that were metrichecked positive (had pus in the cup when metrichecked), at a single whole herd check a month before the planned start of mating, had a 15-20% lower six week in calf rate than the cows in the same herd who were metricheck negative. That is a huge impact on herd fertility!
A large NZ study involving 15,500 cows on 29 dairy farms compared doing one whole herd check with the batched metricheck approach, as above. This study found that the metricheck positive cows identified and treated in the batched approach had a 10% higher six week in calf rate and a 3% higher twelve week in calf rate (or a 3% lower empty rate) than the cows identified and treated using the one whole herd metricheck approach!
So, from legitimate New Zealand research, it is clear that:
Can you afford to leave your dirty cows untreated this coming season? Call your vet to discuss and book in metrichecking soon before the chance passes you by.