New housing changes in the poultry industry may increase the risk of disease if the birds are not properly managed in their new environments, said a laying hen veterinarian with McKinley Hatchery.
Dr. Mike Petrik spoke at the Poultry Industry Council’s Poultry Innovations Conference held in November in London.
Why it matters: Producers will have to adjust how they manage birds as changes to poultry housing bring new disease potential.
Petrik said that overall, new barn design changes, brought on by changes to federal poultry codes of practice, provide opportunities for birds to thrive, but producers may have to change some practices.
“They (chickens) have all the behavioural opportunities that they want, but if they are sick, they are not going to do well.”
Disease risk is higher with the new barn designs and farmers, veterinarians and service personnel all have a role to play in lowering the disease risk, he said.
“We have to be more careful, we have to manage more tightly — we can’t make mistakes. It is still just a risk factor and if we can mitigate that, we will do very well.”
As of April 1, 2017, battery cages have not been permitted in new barns. All battery cages in existing barns must to be phased out by 2036. Farmers must convert to enriched housing or cage-free quarters.
Use of perches, central to enriched cages, is one potentially risky aspect.
“They like (perches), they really do, ask anyone that has furnished cages or an aviary, you go in there at night, everyone is up on a perch,” said Petrik.
However, if not managed properly, the perches create more cases of bumblefoot, a bacterial infection.
Bumblefoot becomes an issue when birds’ feet are damp for long periods of time. Perches must remain clean and dry.
As well, perches that are too small can be an issue.
“The claw can come around and dig into the palm — you’ll get bumblefoot like crazy.”
Another potential increase in disease arises from excessive exposure to manure, mainly in aviary systems. Cleanliness and manure management are important.
Barns with no bedding will have just manure in them and minimal carbon.
“Which is fine, it’s a reasonable substrate. But you have to realize that they’re just walking, eating and dust bathing in manure. You can imagine the disease risk of it.”
Chickens love to eat manure. It increases the exposure to worms, bacteria protozoans and viruses.
“Worms are really delicious for them. Once you get worms in there it’s really difficult as they spread like wildfire.”
Manure management can be difficult. Whether too dry or too wet, both have their issues.
Too dry manure increases the risk of respiratory infections because dust can damage the cilia.
Dust also carries E. coli and other micro-organisms. If the birds inhale dust, everything in the dust can travel deep into their respiratory tracts.
“The problem is the way to manage dust, through sprinklers and humidity. If you try to keep the dust down and it gets too wet, (it can create) ammonia — ammonia causes issues,” said Petrik.
Ammonia is a fine gas and can travel to the lungs, and tracheal systems. This can cause infection, leading to lung issues.
As well, the chances of bumblefoot increase with damp bedding.
A study completed in Turkey found that wet, clean shavings cause just as much bumblefoot as manure.
The feet absorb the water, remaining damp, and this breaks down the defences, allowing the bacteria to enter.
Nesting can also cause problems if the systems aren’t properly managed. Chickens will work harder to lay an egg in a nest than they will work to get food.
In aviary systems, it’s common for there to be one nest with 30 eggs and other nests with none. This can cause smothering.
“Ninety to 95 per cent of eggs are laid in a nest. It takes a pretty bad nest for them not to use it. There has to be something very aversive about the nest for the birds to lay in a cage or on the floor,” said Petrik.
Understanding the cause of laying outside of the nest is a place to start. Then producers can take steps to get birds to spread out and share nests.