A New Study Says Free-Range Chickens Carry More Parasites

We all know the benefits of choosing free-range chicken and eggs over the battery farmed alternative. Our feathered friends can roam wild and take all the dust baths they like, resulting in tastier meat (sorry, Clucky) and better eggs.

But there may be a downside to this backyard-style of rearing poultry. According to a new study from the University of California, Riverside, cage-free chickens are more likely than birds raised on commercial farms to be infected with parasites such as fleas, lice, and mites.

Published online in the Journal of Medical Entomology this week, the study surveyed ten adult hens in 20 different backyards across southern California. Researchers found a greater diversity of ectoparasites, which live on the outside of an organism, on these free-range chickens, compared with commercial flocks. Eighty percent of the birds examined were found to have parasites, with lice being the most common infestation.

Chickens raised on commercial farms were found to suffer from a few of the same ectoparasites but because these birds are often housed in suspended cages and have little contact with the ground, mites and lice have less chance to develop. The researchers also noted that cages on commercial farms provide fewer crevices to harbour ticks. In addition, the flocks housed are usually of the same age and breed, which could reduce the range of parasites.

While there is no risk to humans who eat the eggs or meat of chickens infected with parasites, such infestations can cause stress on the birds, possibly resulting in decreased egg production.

Study co-author Amy Murillo concluded: "Some of the perks [of cage-free chicken farming] might also increase the birds' availability to parasites." She also recommended that backyard chicken owners (looking at you, chicken-kissing hipster) prevent other birds or animals from coming into contact with their flock as a way to limit the spread of mites, lice, and ticks.

Conventional battery cages have been banned in the EU since 2012 and many states in the US also outlaw or limit the use of such cages in chicken farming. But with UC researchers noting that further study on effective parasite prevention is being carried out, let's hope it's not too long before the free-roaming yet lice-free chicken becomes a reality.