The National Animal Disease Information Service (NADIS) is a veterinary based clinical reporting and surveillance system based upon veterinary surgeons on farm visits. As well as recording anecdotal remarks on health issues (summarised in the monthly NADIS report), production and health data is also collected.

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Following a number of years in which a warm spring arrived early, April has been more typical and if anything somewhat colder than expected. As a result many of the problems reported by NADIS monitoring veterinary surgeons are more consistent with what we might expect in winter.

Sows

Whilst last autumn seasonably affected infertility problems, which with the benefit of hindsight were severe for many farms, have now passed, the knock on effects are still evident. Indeed, overproduction in the form of too many sows farrowing has been highlighted as an issue. This has been the direct result of excessive returns to service in November (from September/October servings), which are re-served and hold in-pig to farrow in March. This has implications for farrowing house hygiene (faster turnaround of crates means less time to wash/disinfect and dry pens), weaning age and subsequent performance of both piglets and sows.

Other issues of note that featured in the reports included the ‘off-licence’ use of “long-acting” Oxytocin analogue (Carbetocin (Reprocine: Vetoquinol)), added to semen as an aid to fertility, a procedure that is generating increasing interest.

Conversely, occasional reports of dramatic increases in return to service from individual week’s servings are received. Where the farm uses purchased semen, and there have been no obvious changes in management, such events inevitably lead to both stockman and veterinary surgeons questioning semen quality of the relevant delivery, despite the quality control procedures present on most commercial studs. The major breeding companies take part in the BPEX Standard for Semen Quality in Pig Artificial Insemination (AI) Centres which includes independent auditing to quality standards and independent testing of semen samples at Nationwide Laboratories – Leeds. Testing of semen is rarely possible when problems occur because of the minimum 3 week time-lag before problems can be identified. Another potential factor is temperature changes as these are harmful to boar sperm and must be avoided. Semen should be transported and stored at 17°C ± 2°C. Sudden changes in temperature are very detrimental to the health of the sperm. A rapid decrease in the temperature of the sperm causes cold shock and a rapid increase results in heat shock. Multiple small changes in temperature and reversal of the direction of temperature change of a semen dose are also harmful. Insemination doses must be protected from temperature change from transport right through to the point of insemination.

The temperature in the storage cabinet should be regularly checked and a stable temperature maintained in the insulated container used to transport and store the semen in the service area. Only the number of doses that will actually be used for insemination should be removed from the 17°C storage cabinet and taken out to the sows. The temperature of the transport container can be stabilized by placing two or more gel packs in it that were also stored at 17°C. Each insemination dose should not be taken out until just before it is needed for insemination. Ultraviolet light can also damage the sperm and exposure to these harmful rays should also be minimized.

Piglets

Coccidiosis continues to be one of the most commonly reported conditions affecting baby piglets and given the availability of highly effective preventable medication, albeit an “off licence” product (Baycox: Bayer), it is surprising. Question marks over the correct timing of treatments are commonly raised (timing is critical) but there are also concerns that in these difficult financial times, cost cutting in reducing medication may prove a false economy.

Juvenile Greasy Pig Disease was highlighted as a severe problem and it should be remembered that in these very young pigs death can often result - it is not the mild superficial disease that many take it to be.

Meningitis, joint ill and navel infection were also reported, all of which would raise questions of farrowing house hygiene and management around birth, including colostrum intake. Such problems at this age are frequently associated with contamination and inadequate colostrum intake.

Weaners

PMWS has been very much in focus over the last month not least due to the launching of the BPEX research programme aimed at encouraging producers to commence vaccination against PCV2. Almost half of the national sow herd had registered for this programme within the first 3 weeks, and it provides producers with the perfect assisted opportunity to control a problem that has caused major losses over the last 7- 8years.

Possibly associated with ongoing PMWS problems, veterinary surgeons continue to report widespread illness associated with Glässers Disease and other components of the porcine Respiratory Disease Complex.

Other issues to have arisen in the month included:-

Post-weaning scour possibly associated with chilling.

Slow growth of outdoor weaners thought to be due to cold weather and chilling winds, requiring increased use of feed supply to maintain body temperature rather than promote growth.

Fading weaners immediately after weaning as a result of a failure to take to hard feed - a common individual problem in pigs weaned close to the lower permitted age limit.

Unevenness of pigs at weaning blamed on inadequacy of sow feed provision during lactation, limiting milk production.

Finishers

Again references to PMWS featured prominently with many farms experiencing late onset wasting and PDNS. An often-noted comment from reporters was that these diseases have become more prevalent in the last two moths when the weather has been colder than might have been anticipated. The later onset of the disease may influence decisions as to whether to apply sow or piglet vaccination for PCV2 with the latter still inhibited by supply problems with licensed products. Fortunately, the VMD as the licensing body responsible for permitting importation of vaccines, has acknowledged this supply issue, and is prepared to grant STC licences for non-EU registered product to be used on specific farms.

Scour was widely reported in March and April in growers with the usual suspects - colitis and ileitis - mentioned along with continuing problems with Swine Dysentery on specific farms. Whilst not causing disease, enteric infection with Salmonella continues to be in focus and although changes to the ZAP programme remove some of the threats to marketability, which came with persistent high ZAP level results, reducing the level of Salmonella on pig carcases has become the new goal for the industry.

Pneumonias were widespread - possibly reflecting lower airflows in cold weather but other trigger factors were identified as increased stocking rates (referred to previous monthly reports) and in some cases cessation of Enzootic Pneumonia vaccination as a cost-cutting measure.

Discussion with producers to improve pig flow and allow better hygiene and health management were reported but with some reluctance to accept the need for change, especially if it requires investment during continued uncertain times.

Condemnation at slaughter and clinical outbreaks in straw yards highlighted continued problems with presumed erysipelas infection - something that might be expected to increase as temperatures rise.

The current cold weather may distract producers into forgetting that summer is coming and that sunburn – in pigs exposed to outdoor conditions, not just those kept outdoors – is most frequently severe in May and June with its consequent welfare and production implications.

Mark White BVSc DPM MRCVS

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