Management review gets better of wasting disease
The pig wasting disease
PMWS is having a
devastating effect on units.
Research has yet to come
up with a solution, but
one unit has got the
disease under control, as
Jessica Buss finds out
MORTALITY on one pig unit infected with post-weaning multi-systemic wasting syndrome (PMWS) is almost back to pre-disease levels following some brave management changes.
Hill House Farm at Stradbroke, Suffolk, first suffered a PMWS outbreak in spring 2000. The unit, owned by breeding company Rattlerow Farms, produces pigs for export, but the company stresses that only multipliers in the Norfolk and Suffolk borders have so far been affected by the disease.
It is not known how the disease came onto the unit which follows strict biosecurity practices. But by January, weaner pig mortality had reached 20%. Staff morale was at an all-time low, says the units vet Ian Dennis.
"We realised no treatment that would help reduce mortality was available. We had tried several antibiotic strategies, vitamins and acid enhancers. Vaccines and wormers had also been tried on other units in the area, but there was no benefit."
With little research into the disease in the UK, waiting for a magic potion to solve the units problems was no longer seen as an option, he says. Management seemed the only way to tackle the disease.
In January, stocking density across the whole unit was reduced by 10-15% to ease the stress on pigs and increase immunity to all disease. Steps were also taken to minimise mixing of pigs and ensure the animals were always moved to washed and disinfected pens.
A PMWS conference in Australia reported that such a strategy had proved successful in limiting the disease in France.
Because staff were devoting a lot of time to looking after sick pigs, asking them to take on extra work could have been too much. But they were briefed on the idea and expressed a willingness to try anything, rather than continue losing so many animals.
Within seven weeks of introducing changes to management, the benefits were already becoming apparent, says Rattlerow production co-ordinator Robin Brice.
Six months later, mortality is almost back to pre-PMWS levels. Post-weaning mortality is 5.3% compared with a pre-disease average of 3.5-4%. "Unit staff are confident that this will reduce further."
Pig performance no longer reflects that of a unit with PMWS (see table). "Growth rates have increased through to finishing, reducing days to slaughter by two weeks less than achieved pre-PMWS," he says.
Sow numbers have reduced from 400 to 340 and Mr Brice believes profitability has increased because of the units efficiency.
Many producers try to increase sow numbers to compensate for high mortality or poor performance, he says. "But our experience shows you may as well reduce stocking rate and, with lower mortality, end up producing the same number of pigs more efficiently."
Mr Dennis is now encouraging other units to put what has been learned at Rattlerows unit into practice, even though they may have to compromise on some aspects.
Rattlerow is also reviewing all its units and, where possible, putting these management practices in place to minimise the effects of the disease, should they become infected.
Current pig performance
Period (days) Start (kg) End (kg) Daily gain (kg)
Weaners 31 7 19.2 0.393
Growers 22 19.2 36.2 0.772
Rearer/finsher 62 36.2 93.3 0.921
Birth to finish 142 1.5 93.3 0.646