Poultry producers are being urged to maintain strict biosecurity as prolonged hot and dry weather coincides with an earlier-than-usual rise in Salmonella cases.
Cases have increased across breeder, broiler and layer sites, according to Livetec Systems. While a seasonal rise is expected as summer progresses, the company said the early harvest and prolonged period of hot weather could be bringing additional disease pressure sooner than usual.
See also: EP 37 | Paul Flintoff: What Happens When Salmonella Hits a Broiler Farm
Livetec biosecurity adviser Dr Paul Talling said producers were rightly prioritising measures to keep birds cool, but warned that the effects of high temperatures extended beyond heat stress.
“Birds suffering from heat stress can experience weakened immunity, compromised gut health and exhibit physiological and behavioural changes such as excessive panting and drinking, making them more vulnerable to disease,” he said.
Warm conditions can also allow bacteria and other pathogens, particularly Salmonella, to multiply more rapidly, increasing the number of infectious organisms present.
Maintain normal routines
Dr Talling said consistent biosecurity remained the most effective defence and warned against allowing hot-weather adaptations to undermine established farm routines.
“Where biosecurity is good, producers should not need to change what they’re doing but must be careful if normal routines or infrastructure have to be altered to work around periods of hot weather,” he said.
Dry conditions, the early harvest, muck spreading and cultivation can increase the amount of dust in the environment while also disturbing rodent populations.
Salmonella can be carried by dust, organic matter, soil particles and vermin, making it important to keep the areas surrounding poultry sheds clean and tidy.
Producers should also inspect buildings for gaps that could allow rodents to enter and address any weaknesses in structural biosecurity.
Open doors increase disease risk
High shed temperatures may lead farms to open catching doors, emergency exits or windows to provide additional ventilation.
However, Dr Talling warned that doing so could allow wild birds and rodents to enter and encourage uncontrolled movement by people.
“Once a disease has entered a building, human-mediated transfer is often responsible for disease spreading around the farm,” he said.
“Where doors have to be opened, staff should maintain biosecurity by using only the entry and exit they normally use.”
Bird welfare must remain the priority, but farms should check that fans, air inlets and cooling systems are operating effectively before relying on open doors to increase ventilation.
Drinking lines require closer attention
Water hygiene also becomes more important during warm weather because biofilm can develop more quickly inside drinking systems.
Dr Talling advised producers to flush and disinfect drinking lines every few days, particularly where misting or other cooling systems are being used.
Staff should also continue wearing clean, shed-specific wellington boots and overalls, despite personal protective equipment becoming less comfortable in high temperatures.
“Keep routines in place and control what you can control,” Dr Talling said.
“Use the dry weather to identify and rectify any weaknesses in structural biosecurity and engage with staff to reinforce expected biosecurity behaviour.
“Take these practical steps now and you will significantly reduce your biosecurity risk going into the autumn.”
