Rise in spring listeriosis cases after forage difficulties

Last winter’s fodder shortage resulted in several listeriosis cases across the UK, according to reports from the Animal and Plant Health Agency (APHA).

Several listeriosis cases were reported by veterinary investigation centres (VIC) and the University of Bristol Farm Animal Pathology Service (FAPS) at a time when straw, hay and silage costs had doubled. 

On-farm issues were mainly manifested as abortions in cattle, with some cases of meningoencephalitis (brain and spinal cord inflammation) and systemic versions of the disease.

Cases were reported in the latest GB Emerging Threats report – which runs from January to March – and again in the monthly update for April.

See also: Advice on silage aftercut nutrition in a late spring

Commenting on the rise in cases, the APHA said: “Silage feeding is identified as a risk factor for listerial infection, as the bacteria can survive, and proliferate, if optimal anaerobic fermentation conditions are not achieved.

“This is most likely if the silage is made when wet, where excess soil is incorporated, if air is not excluded from beneath a clamp cover or perforations occur in bale wrappings.

Advice from the National Animal Disease Information Service (Nadis)

Treatment and control

  • High doses of penicillin have been recommended on day one
  • More conventional doses then continue for next seven to 14 days
  • Watch for loss of saliva and drinking difficulties
  • Care must be taken when replacing fluids with oro-gastric tubes due to anorexia-caused rumen contractions that can result in passive regurgitation around the stomach tube

Prevention

  • Achieve good grass fermentation by cutting earlier (D value of 72)
  • Cut grass for high sugar content
  • Wilt 24 hours
  • Use silage additives to help ensiling process – sugars or organic acids
  • Compact silage, expelling air
  • Seal tightly to prevent aerobic bacteria breeding
  • Avoid soil contamination – reduce by rolling fields early in the growing season

See the Nadis website for more information