BIOSECURITY is often highlighted as a priority in the winter months when the threat of avian influenza is higher.

But it is just as important in the summer when a range of factors can increase the risk of an incursion of salmonella on both egg or broiler farms, according to Livetec Systems’ technical officer Sarah Russell.

See also: How to set up and operate ventilation for broiler chicks

“We often see a spike in cases in the summer, when harvest gets underway,” she says. June this year was exceptionally hot, with some parts of the country getting hardly any rain, for example.

The firm, which specialises in on-farm culling, reports most of its salmonella-related call outs during the warmer months. But it also offers a biosecurity consultancy service to help businesses minimise risk.

“It is a tiny number of farms, but it is in August and September that we see the most cases,” she explains.

One of the significant factors during the summer is dry weather, which creates more dust – a vector for salmonella, potentially carrying it into poultry farms through ventilation or on clothing.

But there are many other factors at play; rodent activity can increase as crops are disturbed, for example, and pig manure is often spread on stubble that may be adjacent to farms, creating risk.

Farm situation

Every poultry farm is different, and the first step in reducing risk is to review your farm, explains Ms Russell.

More specifically, consider if there are pig units nearby. Does a local shoot release pheasants in the summer months? And what arable activities take place – even if they are separate businesses?

Consider the prevailing wind, and what it might be blowing from adjacent areas towards your poultry units.

If the farm is mixed, think about how staff move between the different enterprises and ways to minimise that movement to mitigate risks.

In the summer staff can be rushed between helping with arable harvests, for example, and keeping pig and poultry units operating.

Dust and detritus can stick to clothing and be carried into sheds.

“It’s vital to change boots and have dedicated clothing for poultry house; the evidence is that dust can carry the pathogen,” explains Livetec’s Julian Sparrey.

Free-range units need to keep bird areas as dedicated poultry areas – fenced off with no access to other livestock or farm pets, he adds.

Cleaning, disinfection and farm maintenance

Within the sheds themselves, cleaning ventilation systems becomes even more important when dust is more prevalent; a patch left in a hard-to-reach spot can harbour salmonella for weeks, and potentially introduce it to the next flock.

Consider where manure is being stored. “The farther away you can move it, the better,” Mr Sparrey says. “Don’t just leave it close to the poultry sheds.”

Review the condition of grain silos, as well. While in-depth inspections can be challenging, simply looking at the condition and whether there are any apparent holes is an important step to take regularly.

Wild birds accessing feed has been found to be the source of salmonella on several farms in the past, says Ms Russell.

Plug any gaps that may allow wild birds access to shed interiors, as well, and consider ways to discourage them from the general farm area – cleaning spilt feed is crucial.

Time spent now addressing housekeeping issues could pay dividends in the late summer and early autumn.


While the autumn is usually considered the peak time for rodent populations to be active and trying to access poultry sheds, harvests can drive rats and mice from fields and towards farms.

And this year there have been reports of rodent numbers increasing as their natural food sources have been disturbed.

Lockdown has meant pubs and restaurants are closed, meaning less waste food and lower traffic levels have reduced the amount of roadkill generally on offer.

A recent survey by the British Pest Control Association found 51% of pest controllers have reported a rise in rat activity and 41% have reported a rise in mouse activity since March.

On the poultry farm itself, keeping strips of vegetation around units clear is part of most assurance schemes now, and removing any old machinery or equipment that can act as a shelter for rodents is essential, adds Mr Sparrey.