Complex cases of retained foetal membranes (RFM) can lead to health problems for cattle and can be costly to a herd. Josh Swain, vet at Synergy Farm Health, explains how effective management and vigilance can help.
What are retained foetal membranes (RFM)?
The definition of when the placenta or foetal membranes become retained is vague. In most calvings expulsion of the membranes occurs within eight hours, with 24 hours is often used as a cut-off.
The incidence of RFMs differs between herds and is typically higher for dairy cows than beef, with average rates of between 5-15%. Some studies have suggested a target of below 5% is suitable and that rates of over 10% should be investigated.
What impact can they have on the herd?
Estimating the cost of RFMs is difficult as the severity of the condition varies – with almost half of RFMs having no impact on fertility. There is even some doubt as to whether uncomplicated RFMs have any impact on milk yield.
However, cows with RFMs are at an increased risk of metritis and endometritis or “whites”, which can lead to more complex problems and is known to affect fertility.
An average cost of just over £200 due to a loss of milk, reduced fertility and veterinary costs has been attributed to RFMs, but this can vary widely.
How do you treat RFMs?
Nearly half of RFMs require no treatment and have no impact on the cow’s health and subsequent fertility, even when retained for up to 15 days.
Manual removal is commonly carried out as a treatment, but also partly for hygiene or cosmetic reasons to remove the unpleasant mess hanging from the back end.
Manual removal can however, damage the uterus so should only be attempted if membranes come away with very little traction. If they is a problem in the parlour, it is safer to trim them away, which can help reduce contamination.
In the case of uncomplicated RFMs, antibiotics (both systemically and in utero) have no benefit and possibly delay recovery. Treatment with hormones such as oxytocin, oestrogens and prostaglandin have all been shown to have no benefit.
Antibiotics, however are important in cases where RFMs leads to metritis. Metritis makes cows systemically sick with a reduction in appetite and drop in milk yield.
These cows require systemic antibiotics and non-steroidal anti-inflammatories along with additional observation and care.
Ideally, to aid prompt treatment, all cows with RFMs should be monitored closely for milk production and have their temperature taken daily using a thermometer (normal temperature <39.4C) until the membranes have passed.
Additionally, all RFM cows should be presented for post-calving checks three to four weeks post-calving as RFM and metritis cows have an increased risk of endometritis, which is associated with reduced conception rate.
When should you use antibiotics?
Only those cows with RFMs complicated by metritis (high temperature, reduced appetite and drop in milk yield) should be treated with a course of systemic antibiotics. Penicillins such as amoxicillin are often suitable as a first-line treatment and have a minimal milk withdrawal.
Another group of antibiotics, the cephalosporins, have been widely used to treat metritis.
However, routine use of these should be avoided, especially the third and fourth generation cephalosporins, which are designated critically important by the World Health Organization.
What are the risk factors?
Multiple risk factors for RFMs have been identified. Many occur at calving such as dystocia, twins, abortions and premature calves (including pharmacologically induced pregnancies).
Nutritional risk factors have also been identified including over-conditioned dry cows, deficiencies of certain antioxidants and trace elements (such as selenium, vitamin A and E, β carotene and iodine) and negative energy balance.
Older cows are more likely to be affected than heifers.
How do you prevent RFMs?
RFM is a complicated condition with many risk factors at play. As with all diseases around calving, maintaining feed intake, avoiding stress, ensuring adequate nutrition and maintaining a hygienic environment are key to success.
Good transition cow management by ensuring plentiful feed space and lying areas as well as maintaining stable groupings by avoiding pen movements three to seven days pre-calving will help maximise feed intakes.
The diet should have adequate levels of vitamins and minerals especially vitamin E and selenium.
Only supplement if a deficiency has been shown on farm, as not only is it an added cost, there is some evidence to suggest over supplementation may increase the risk of RFM.
Selecting sires with easy-calving EBVs and avoiding over-conditioned cows will help to reduce hard calvings.
Fat cows or those with twins may benefit from a monensin (kexxtone) bolus three to four weeks before calving to limit subsequent negative energy balance.