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NADIS Pig Veterinary Report and Forecast - June 2008

by 5m Editor
1 July 2008, at 7:34am

UK - 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.

A busy month of veterinary activity on pig farms has coincided with some rise in optimism for the industry as prices show some signs of beginning to rise and control measures for PMWS start to be put in place, assisted by the BPEX research programme on PCV2 vaccination.

Adults

As usual problems reported in the breeding herd can be conveniently divided into production issues and specific diseases with some overlaps.

On the production side, to emphasise how events can have long term implications, the dip in fertility seen last autumn has been followed in many cases by a compensatory recovery with more recent excess farrowings putting pressure on farrowing houses with implications for weaning age and farrowing house hygiene. Despite this widespread picture a number of reports suggest some herds experienced a drop in fertility (and numbers born) for November and December services for indeterminate reasons. Furthermore sporadic cases of dramatic return to service in gilts in the New Year has triggered a dip in recent farrowings and a need for a review of overall gilt management. A few comments suggest that a number of producers are beginning to drift towards a mixed service regime (boars and AI) perhaps suggesting an easing of the trend towards pure AI use.

Unusually, oestrus in sows still lactating was reported, with the consequent difficulties that this brings in rebreeding. On the disease front, reproductive problems were associated with a major PRRS outbreak (following perceived re-introduction of the virus via visitors) and possible influenza infection triggering a wave of irregular returns.

Skin disease featured in a number of reports and included mange and lice (– the latter very rare on commercial farms) an intensely irritant condition that was not mange but remains under investigation and localised greasy pig disease. Cases of Erysipelas were seen. One herd reported 6 cases of “meningitis” in sows – of which 3 animals died – but the cause remains unknown.

Piglets

Piglet health problems were prominent in reports in late April and May and included a wide variety of scour problems – especially associated with Rotavirus, Coccidiosis and PRRS but also including non-specific scour associated with hygiene breakdowns – pressure on farrowing space obviated cleaning. Similar failures were attributed to an increase in joint-ill and meningitis on a number of units.

Piglet quality around birth was highlighted as contributing to losses and the causes were variably attributed to previously identified problems with sow condition and in a series of farms attributed to the inclusion of maize in the diet. Given the higher energy levels of this product compared to wheat/barley, this might suggest either formulation error or digestibility problems.

Other sporadic problems in piglets reported included outbreaks of savaging by gilts and scald in newborn pigs attributed to milk leakage from teats (wetting floors) following incorrect use of medication to trigger milk letdown.

Weaners

Overstocking following excess farrowing continues to be a common theme in weaners and in some cases a switch to cheaper weaner diets - as a cost cutting measure – has further slowed growth. This creates a vicious circle. Problems were also experienced with low weaning weights as a result of poor nutrition of sows with a consequent rise in post weaning mortality. A switch to weaning pigs into outside kennels (for unspecified reasons) led to a rise in mortality – presumably not the desired outcome.

Despite the uptake of PCV2 vaccines in more than half of the national herd, for many farms the benefits are yet to be seen, although a number of reports of more even groups of weaners were received. PMWS was widely reported and in a number of farms was increasing in prevalence in the spring triggering consideration of vaccine introduction.

Other specific disease issues seen during the month included:

Typical post weaning E.coli scour and mortality – in at least once case associated with early weaning following farrowing house overspill.

Meningitis attributed to variable weather conditions.

Non-specific coughing around weaning that whilst dramatic did not appear to check pigs.

Problems secondary to PRRS in the farrowing area that affected both weight and quality at weaning. Meningitis was a natural consequence.

Growers/Finishers

Respiratory disease continues to dominate the picture in the growing herd with a wide range of specific problems reported. These included:

A whole herd cough outbreak believed to be associated with Swine Influenza.

Generalised increase in respiratory problem following increases in stocking density.

Increase in SEP and PRDC following a decision to withdraw SEP vaccine (as a cost cutting measure).

PRRS triggered respiratory outbreaks.

Late onset PMWS and PDNS which it is hoped that vaccination for PCV2 infection – especially where used in piglets – will control.

Chilling triggering outbreaks of pneumonia including complications with Strep Suis and Actinobacillus pleuropneumoniae infection.

Whilst the BPEX PCV2 research programme did not start until April, these vaccines were available prior to that and a number of reports show encouraging signs of improvement levels of PMWS and overall health, growth and evenness. It is hoped that the data collected as part of this programme will quantify and confirm the cost benefits of vaccination.

The other major syndrome usually reported in growers is looseness or scour but over the last couple of months there has been a general decline in levels (see graph below) with veterinary surgeons reporting far less disease.

This begs the question of whether dietary changes following price pressures have had an incidental beneficial effect. Notwithstanding this decline, swine dysentery continues to be sporadically reported and some farms actually saw an increase in scour following inclusion of maize in diets or in one case following reduction in feed acidification.

An outbreak of ‘bloody gut’ or PME – the acute haemorrhagic form of ileitis in a herd vaccinating around weaning affecting one batch only brought into question vaccination technique with a suggestion that antibiotic medication may have interfered with this live oral vaccine.

Aggression problems continue to be reported with tail, flank and ear biting all seen. A lack of ‘toys’ in slatted accommodation was highlighted in a number of cases but general fighting problems raised a question mark over breed type, with some stockmen adamant that Hampshire progeny are more aggressive.

Septic arthritis – requiring euthanasia – was highlighted as a significant welfare issue and serves as a reminder of the need to cull animals quickly that are suffering and will not recover to make a presentable carcass. With current high feed cost there is no economic sense in keeping such animals alive.

Abattoir reports continue to reveal milk spot liver problems on previously unaware herds, along with the sudden appearance of Actinobacillus pleuropneumoniae lesions at slaughter with no clinical disease on farm.

Despite the recent changes to the ZAP Salmonella scheme (see April’s report) this infection continues to be the focus of attention with poor hygiene unsurprisingly blamed for high scores on some farms.

As we now finally look to be heading into summer weather, producers should anticipate a range of issues associated with hot weather:

Sunstroke and sunburn
Reduced fertility in hot weather
Erysipelas
Increase in scour
Respiratory disease in straw yards

5m Editor