Sheep - Lambing
Preparing for the Lambing Season
Christmas and the lambing season both seem to last much longer than they did in the old days. For many people (though regrettably few in the livestock industry) the festive break is no longer restricted to the traditional three winter bank holidays. Nowadays, it stretches out languidly across the best part of a fortnight. Similarly, lambing has stopped being that burst of activity experienced by flock holders and their veterinary surgeons during a few weeks in early spring. Instead, in some lowland flocks the first lambs will start appearing in mid December and yet for others in the same area, lambing may not be over until the end of May.
Christmas and lambing seasons have something else in common - good advance preparation is essential to their success. So well before the last mince pie disappears, sheep farmers should be thinking about what they need to be doing to ensure that they can look forward to a prosperous New Year with a healthy crop of newborn lambs, according to Andy Barrett, a partner in the Skipton-based Kingsway Veterinary Group.
Getting the ewe’s nutritional state right in the weeks before lambing is the most important element in this preparation. Ewes have to be in optimal body condition for the rigours of the last six weeks of pregnancy when 70% of foetal growth occurs and particularly the final two weeks, during the peak phase of udder development. Getting it wrong will result in low birth weight lambs and poor quality colostrum which will both lead to poor survival rates.
Ewes should be grouped according to the numbers of lambs found on ultrasound scanning and their general condition score. Thin sheep and those with twin or triplet lambs can be given extra rations with the goal of producing target body condition scores of around 3 in lowland flocks and perhaps 2 on leaner lambing hill ewes. Improving the BCS of a thin animal takes some time so flock holders should not leave this selection until the last minute. “They should be checking at least two months out, leave it much later than that and all that you can really achieve is the fine tuning,“ Mr Barrett warns.
The need for supplementary feeding will depend on the quality of the forage available as well as the nutritional state of the animals. Most flocks will start receiving extra rations 6 to 8 weeks pre-lambing with good quality concentrate introduced slowly and always less than 0.5 kg per head to avoid the risk of acidosis. Getting the mineral balance is also important, calcium concentrations should be below 1% and magnesium levels should also be kept low. “Flat rate feeding is easier and getting more popular but it requires good quality forage and may not be suitable for very thin sheep,” he notes.
Those farmers intending to lamb indoors should also be thinking about housing. A typical 70 kg ewe requires 1m² of floor space and 450mm trough space - overcrowding will lead to a host of problems resulting from stress, poor hygiene and rapid disease transmission. The sheds should have draught free ventilation and there should be plentiful stores of clean, dry bedding. If ewes are being brought indoors, this should be done at least two weeks before lambing at a time when their fleece is dry to avoid introducing excessive moisture.
Although lambing activity may be less concentrated than in the past it is still a time when an extra pair of hands may be valuable. Veterinary students may traditionally formed a useful reserve on many sheep units and it may be therefore be worth ringing the schools well in advance to check on availability. For any extra staff, whatever their level of training it is always sensible to prepare protocols to explain what is expected of them in particular situation - dystocia, prolapse, colostrum feeding and hypothermia, Mr Barrett notes.
When those lambs do start to appear, it is inevitable that there will be some losses to disease. But these can be greatly reduced with appropriate preventive treatment. Flock holders should be discussing their vaccination policies with their veterinary advisors well in advance. In the case of the most readily controlled fatal condition of newborn lambs, clostridia disease, the best time to be treating the dam is between six and eight weeks before lambing.
Other diseases of both ewes and lambs are best dealt with careful monitoring an prompt treatment. Farmers and their vets should be investigating the possible risk factors in any conditions, hypocalcaemia, prolapses, etc if there has been multiple incidents. A particularly close eye should be kept on those ewes that are at most risk of developing of twin lamb disease, or pregnancy toxaemia. This may include ewes at both ends of the size range - “Thin, overfat and shy feeding sheep as well as those carrying multiple pregnancies are most at risk,” he warns.
Finally, and again like Christmas, preparing for the lambing season involves a fair amount of shopping. The box below is a check list of the products and materials likely to be needed around lambing time. December is a good to checking stocks and if any are in short supply, farmers should be asking their vet for prices.
- Lambing rope/snare
- Stomach tube/lamb feeder
- Colostrum (ideally frozen ewe if not goat or cow or powdered)
- Antibiotic injection, aerosol spray & oral drench
- Respiratory stimulant
- Glucose 40% injection
- Calcium 20% injection
- Propylene glycol/twin lamb drench
- Iodine navel dip
- Prolapse retainer