The likely cause of the sudden deaths of cows on a Jersey farm has been found.

The cattle which died suddenly in large numbers on a Jersey farm, most likely died from botulism, the island’s chief veterinary officer has said.

More than 100 cows at Woodlands Farm died over the course of a few days in mid-December.

Although the results of government-commissioned tests on the cattle feed have found no toxins present, toxin-producing bacteria were cultured from samples. 

Chief veterinary officer, Susana Ramos, said: “Botulism has been our main working theory throughout. It’s characterised by progressive muscle weakness. Cattle are extremely sensitive to the toxin, and in most cases it is fatal.

“Botulism is notoriously hard to test for, and diagnosis is often based primarily on the clinical signs and by ruling out other possible causes.

“Despite no toxin being found, there was the presence of bacterial spores, and we believe that these results, coupled with the exclusion of notifiable diseases, and the signs reported at the time at the farm, all combine to suggest botulism as the most likely cause of death.” 

The results of the feed sampling, analysed by scientists in the UK, came through to the government of Jersey on Thursday night. 

Director of natural environment, Willie Peggie, added: “We have been able to rule out a number of causes, by a process of elimination but have not been able to identify the toxin; we were aware from the outset that a conclusive laboratory result might not be achievable. 

“We have no reason to believe that there is any further risk to animals, or any risk to the general public.” 

Botulism is a paralysing disease which kills most affected animals. It is caused by a highly lethal toxin which is produced by Clostridium botulinum, a bacterium found in soil, which multiplies in rotting vegetation or carcases.

Defra says that in UK ruminants, the disease is often caused by animals coming into contact with the litter of broiler chickens especially if it contains any carcase material.

There are also more sporadic but very large outbreaks due to feeding forage that has been contaminated with carcase material, including carcases that have been ensiled during grass cutting.