Managing your ewes correctly in the last few weeks before lambing is one of the most critical stages in the sheep calendar. If things go wrong at this stage then lamb birth weight could be low, lamb losses high, colostrum supplies and quality poor, and subsequent lamb growth well below target.
Fortunately, we are now able to learn important lessons about these issues from fallen stock, particularly preventing unnecessary lamb losses. Indeed, post mortems carried out at a fallen stock collection centre in North East England and rapid feedback of the results is already helping sheep farmers take action to prevent further livestock deaths.
Between April 2015 and March 2016, vet Ben Strugnell from Farm Post Mortems Ltd. – based at John Warren ABP in County Durham – examined nearly 2500 carcasses from more than 1000 beef and sheep farms across the north of England. The work, funded by AHDB Beef & Lamb since March 2014, has identified the main causes of the stock deaths and highlighted what action needs to be taken to reduce what are often preventable losses.
“With two years worth of data the project has highlighted just how useful it is to identify the cause of death in order to act quickly to prevent further losses. There were literally hundreds of reasons why the animals died, but identifying the top ten causes for each class of stock has really brought home the important ones,” Mr Strugnell says.
“As many as 40% of the livestock losses could have been prevented – either through the correct use of veterinary medicines, good colostrum uptake or improved animal health product administration techniques. By feeding the information back to the individual farmers and then informing and educating producers nationwide we can help prevent further losses.”
Saving more lambs
According to Mr Stugnell, more than one in five of the dead lambs submitted died as a consequence of parasites, if deaths due to worms (including nematodirus) and coccidiosis are added together. However, particularly interesting was a spike in pasteurellosis and clostridial disease in the autumn of 2015. This followed a similar picture in 2014.
“Pasteurellosis is an opportunistic disease that often requires a trigger to initiate it, such as worms, border disease, trace element deficiency, adverse weather or overstocking. Autumn has always been a risk period for this disease and we certainly saw an increased incidence in autumn 2015 over autumn 2014. This autumn peak of disease is consistent and concerning, and has important implications for its control. It suggests that if producers are keeping store lambs during this period they should talk to their animal health provider about vaccinating them correctly,” Mr Strugnell says.
Unnecessary lamb losses from clostridial diseases such as pulpy kidney were another cause for concern. “In year one of the project there was a large peak of pulpy kidney in the early spring where lambs aged between two and eight weeks of age were affected. In almost all the cases neither the dams nor their offspring had been protected by vaccination.
“There was a second peak in the autumn, which was very noticeable in year two (2015). It may be triggered by changes in gut flora, notably the proliferation of clostridia occurring as a result of dietary change (e.g. the introduction of hard feed).
“In the case of the fed lambs, most had not received a booster prior to the change of diet and any immunity they may have had from drinking colostrum at birth will have waned. In general, clostridial vaccines in sheep work well and are cost effective, which means that most of these losses are preventable.”
Lessons from fallen sheep
- For ewes: iceberg or production limiting diseases, such as OPA and Johne’s disease, need to be addressed by the industry
- For lambs: worms, pasteurellosis and clostridial diseases accounted for a significant number of lamb losses. Vaccinating ewes against clostridial diseases will give lambs a better chance of survival. Don’t forget the booster 4-6 weeks pre-lambing so that lambs can gain valuable passive immunity in early life through drinking colostrum from their vaccinated mothers.
For a full report on the fallen stock project visit the AHDB website:
This is an abbreviated version of an article first published in the spring 2017 issue of Sheep & Beef producer magazine.
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