RFMs, or the smell of spring, have a colourful past and the way we have treated them has changed dramatically over the years. When I first qualified we used to pull, tug, lean and generally wrestle them out if we could and then throw in a handful of pessaries or irrigate the uterus with Lotagen. How times have changed-it seems that the damage we did to the uterus greatly reduced the chances of that cow getting in calf quickly or at all. The latest research and advice points towards leaving them alone for as long as it takes with no treatment, unless the cow is sick, and then identifying those cows as At Risk cows for treatment closer to mating.
Membranes are considered retained if they haven’t been expelled within 12 hours of delivering a calf. If they aren’t released in that time, the progressive decline in uterine activity means that they will probably not be released until they have undergone ‘liquefying putrefaction’ (nice!) and will be spontaneously expelled about 6-10 days later. Obviously the uterus at this time has considerable amounts of infection in it and that will require treatment, probably with a Metricure a week or so after that. These are your so-called “At Risk” cows. If we try and force the removal of those membranes, we simply slow the whole process down and damage the lining of the uterus at the same time.
What causes RFMs? A few known risk factors include:
Abnormal gestation length, either too short or too long
Primary uterine inertia (i.e. an exhausted uterus that loses the ability to contract and expel membranes)
Twins or induced calvings
Latest recommendations in treatment:
Ideally, removal of membranes should not be attempted until at least 96 hours after calving, and, even then, it should be limited to withdrawal of membranes that have already detached. If attempts to remove are unsuccessful, they should be cut off at the level of the vulva and left until they are shed naturally.
No further treatment is given unless the cow appears ill. If they are sick, veterinary attention should be sought and antibiotics are probably required.
Forced manual removal (as explained above)
Oxytocin-this only works if given at the time of calving. It won’t do anything a few days later
Pessaries- there is plenty of evidence that pessaries probably delay shedding of membranes so tend to impair rather than improve subsequent fertility.
Once the membranes have gone, identify these cows for examination and treatment with Metricure about a month before calving or sooner if they are obviously infected.