Cattle could be exposed to botulism by spreading poultry litter

Investigations by the Agri-Food and Biosciences Institute (AFBI), have provided strong circumstantial evidence that broiler litter is a risk factor for many of these outbreaks.

AFBI and the Department of Agriculture and Rural Development (DARD) have been working closely with the livestock and poultry sectors in Northern Ireland to help ensure that producers are aware of the most effective control measures. Reports from private veterinary surgeons, and a reducing number of submissions of suspect botulism cases to AFBI Veterinary Sciences Division, indicate that the various control measures already implemented by the industry are having a positive impact on the incidence of this disease. However, as cases continue to occur, AFBI wishes to advise farmers on the steps that may be taken to prevent botulism in cattle.

Cause of botulism

Botulism is caused by toxins produced by Clostridium botulinum bacteria. These organisms are commonly found in the environment and will grow to high levels in decaying organic matter including animal and bird carcases. It is believed that contamination of broiler litter with the carcases of chickens that have died from various causes during production can render the litter dangerous for cattle. It is speculated that even small fragments of carcases transferred onto pasture by scavenger animals such as foxes, dogs or crows, can pose a risk to grazing cattle. Scavengers may gain access to this material after it has been stacked outside or spread on pasture.

It is important to note that there is no evidence that manure from laying hens has been associated with outbreaks of botulism in cattle.

Clinical signs of botulism

Cattle of all ages are susceptible to botulism, which is characterised by a progressive muscle weakness (paralysis). Affected animals may be weak, stagger about, or go down. In most cases the disease is fatal although some animals may recover. When a large amount of toxin has been ingested, the animal may be found dead without having shown any signs of disease.