8 October 1999

Management solutions prevent salmonellosis

DAIRY producers must consider adopting management strategies as the solution to preventing a herd outbreak of salmonellosis.

"In future, the use of antibiotics to treat sick farm animals is going to become increasingly difficult. Livestock producers are going to have to adopt a new mindset, moving away from thinking about treatments and towards prevention," Bradford Smith, of California Universitys Vet School told the World Veterinary Congress in Lyon, France.

Clean pens

"That means introducing a series of management solutions including good rodent control on units and eliminating birds from feed storage, isolating sick animals in clean hospital pens, never using contaminated equipment and only clean, non recycled water free of faecal contamination. In addition, carrier animals should be identified and either culled or treated vigorously.

"Producers should also be aware of those animals with reduced resistance to the bacteria, for example those with rumen acidosis, BVDV, or displaced abomasums."

Vaccines were available, but could lead to adverse reactions such as pneumonia and diarrhoea and had only short term efficacy. More effective vaccines were scheduled to be launched within the next few years to help control the disease in calves, he said.

"Salmonella outbreaks are increasingly common with up to 80% of dairy units infected with the bacteria in western USA, and they can create big, big problems," said Dr Smith. The regions high temperatures were ideal for rapid bacterial multiplication on these large scale dairy herds which averaged 1000 cows, and could have up to 23,000 animals.

Affected herds suffered huge financial losses as a result of milk yields falling by up to 30%, abortions, diarrhoea and other health problems, together with loss of genetic potential as a result of calf deaths. In addition, the bacteria posed a major potential health problem in the US that was soon likely to explode, warned Dr Smith.