Metrichecking
Studies have shown that checking just the ‘at risk' cows will detect only around 30% of the cows that develop endometritis after calving.
Previously, detection of endometritis was by observation of discharges from the vulva or a combination of manual palpation of the uterus, speculum examination of the cervix or a gloved hand examination of the vagina. While of value, these methods were limited either by low sensitivity (i.e. a high number of cases missed) when used in isolation, or were too time-consuming to apply to large numbers of animals.
Since the development of the Metricheck device in 2007, not only can the whole herd now be checked efficiently but the detection rate of endometritis within seasonal calving herds has improved. The Metricheck has been calibrated against various other methods and has consistently proved its worth. A 2009 study compared the results of the Metricheck against the collection of cells from the endometrium (cytology) and bacterial culture and found good correlation in both cases.
Does the timing matter?
Less than 14 days after calving, some discharge is normal. A dark red discharge with no associated odour is normal from days 5-7. A clear mucous-like discharge with flecks of pus is normal between 7-14 days. If either of these discharges has a strong unpleasant odour it is abnormal. If the flecks of pus persist beyond 14 days, even without an associated odour, the discharge is abnormal.
Below 14 days, normal discharges are part of the cleaning up process post-calving and treatment is unnecessary. Abnormal discharges below 14 days require treatment usually with an injectable product such as penicillin.
The Metricheck is therefore intended to detect endometritis 14 days or more after calving to avoid over-diagnosing problems and hence treating cows unnecessarily. An intra-uterine infusion is the preferred treatment 14 days or more after calving.
Whole herd or batches?
The current recommendation is to metricheck the whole herd 21 days prior to the start of mating. This allows most of the herd to be calved at least 14 day before examination and allows sufficient time before mating for treatment to take effect. However work in Australia has found that treatment of endometritis between 14-28 after calving is more effective than treatment given after 28 days. If a herd is checked just once then cows with endometritis that calved during the first 5 weeks after the planned start of calving will exceed the 28-day recommendation. In a seasonal calving herd, this means metrichecking and treating on more than one occasion which is a less attractive option than a whole herd metricheck on one day.
However the improvement can be incorporated without as much disruption as might be expected. By metrichecking on three occasions at 5, 9 and 11 weeks after the planned start of calving, only the Metricheck at 5 weeks is an addition to the current repro program being used on many farms. The 9-week Metricheck is the same date as the current whole herd Metricheck date and the 11-week Metricheck can be made to coincide with the examination of NVOs 7 days prior to the planned start of mating.
Examining cows in batches will not suit every situation and the proposed outline above is not necessarily the best option on every farm. However if you consider that metrichecking cows in batches could work in your situation, discuss this with your vet to determine the best approach.
