With in-lamb ewes in generally good order and scanning results high, with plenty of triplets and even more quads than normal, farmers are being urged to keep an eye on their sheep as we head into the most critical stage of pregnancy. Louise Hartley reports.
Mr Lewis has received nearly 20 phone calls in the last 14 days from farmers reporting early incidences of twin lamb disease.
He says: “With a mild winter there has been an abundance of grass in fields across the UK and in general, with ewes being in good condition, many farmers have not felt the need to supply additional forage and the usual energy supplements.
“However, this year we have had one of the wettest years on record, meaning although grass cover is still good for the time of year, farmers are under the assumption extra feed has not been needed.
“Due to the low DM of the grass, ewes are struggling to eat enough forage to achieve the required energy intakes, and could be at risk of twin lamb disease.”
Reports of higher scanning percentages in flocks also mean farmers should be vigilant, as ewes with multiple lambs will be susceptible to the disease.
“Cases of twin lamb disease can almost guarantee the nutritional status of the flock is also on a knife edge,” says Mr Lewis.
“Farmers need to get their feeding strategy sorted and tailor rations accordingly. The easiest way to plug that energy gap right now is to feed energy dense feeds such as lick buckets, blocks or liquid molasses and introduce compound feeds accordingly.”
With many Basic Payments yet to arrive, farmers may also have been holding off buying their usual compound feed requirements, says Mr Lewis.
Dr Phill Scott, University of Edinburgh and contributor to the National Animal Disease Information Service’s regular health bulletin provides advice on dealing with twin lamb disease.
Ovine pregnancy toxaemia (twin lamb disease) is most commonly encountered in lowground flocks, affecting older ewes carrying three or more lambs during the last month of gestation.
On farms which rely almost exclusively upon pasture-based systems with little supplementary feeding, twin lamb disease is seen in severely underfed twin-bearing ewes.
It occurs following a period of severe energy shortage, whether the result of poor roughage quality, inadequate concentrate allowance or high foetal demand, but clinical signs can be precipitated by a sudden stressful event such as adverse weather conditions, handling, vaccination or housing.
The disease’s response to treatment is generally poor, even when clinical signs are detected early.
Housed ewes should be penned separately and offered palatable feeds to promote appetite, and fresh water.
If ewes are housed, turnout to good pasture may promote appetite although such grazing is seldom available.
Treatment with propylene glycol, intravenous glucose injection, and glucocorticoid injection is successful in about 30 per cent of cases which are still able to walk when treatments commence.#
Ewes with pregnancy toxaemia must be checked at least twice daily for signs of abortion/lambing because they may be too weak to expel the foetuses/lambs. Failure to expel dead foetuses leads to them becoming rotten, releasing poisons into the ewe’s system which leads to death.
Those ewes which do recover from pregnancy toxaemia are rarely able to nurse a single lamb and should generally be culled once they have regained body condition. Wool slip occurs commonly in these recovered ewes four to six weeks after abortion/lambing.
Ewes with multiple lambs must be fed appropriate levels of high quality roughages and supplementary concentrate feeding during the last six weeks of pregnancy.