Farmers are often accused of raising livestock on “factory farms” and therefore treating their animals cruelly if they are house their animals indoors. Of course the opposite is true. The purpose of indoor housing is to protect livestock from harsh external environment, and to decrease exposure to internal and external parasites and diseases spread by wildlife, insects or other vectors, thereby improving their overall health.

Animal agriculture, like any other science-based practice, continues to evolve as informed by research by animal scientists and veterinarians who search for environments that provide for animal health and welfare, while minimizing risk to farmers, their employees and the environment.

While activists insist that livestock are better off living outdoors, many studies have proven the opposite. Yet another report was recently published in the Journal of Medical Entomology, “Diversity and Prevalence of Ectoparasites on Backyard Chicken Flocks in California,” which identified the increased prevalence of ectoparasites in “backyard chickens” as compared to commercial raised chickens, housed indoors.

The researchers reported ectoparasites collected on 80% of the premises in southern California surveyed included:

lice (Phthiraptera: Ischnocera and Amblycera), fleas (Siphonaptera), and mites (Acari: Astigmata and Mesostigmata). Lice were the most prevalent and abundant of all ectoparasite groups . . . . The chicken body louse, M. stramineus, was collected on 50% of premises and 36% of birds. It was the most abundant species recovered and sometimes was quite dense on individual birds, with dozens to hundreds of specimens seen.

Notably, “the species [the researchers] collected in backyard flocks have been rare or absent in commercial battery-cage layer flocks in southern California over the past 30 years.”

These results are not surprising.

Increased prevalence of infectious disease and parasites is a well-known risk of outdoor housing of livestock.

This is reflected in USDA’s pseudorabies program (a disease affected primarily swine) which requires more rigorous testing and other requirements of “transitional herds” as compared to “commercial herds” based on the increased risk of the spread of this virus in transitional herds, which the agency defines as:

Those feral swine that are captive or swine that have reasonable opportunities to be exposed to feral swine.

In comparison, USDA defines “Commercial production swine” as

Those swine that are continuously managed and have adequate facilities and practices to prevent exposure to either transitional production or feral swine.

These designations have real-life consequences for farmers, states who implement the federal programs, and ultimately the ability of the entire national industry to export swine and pork products since access to interstate and international markets is based on the disease status of a region, state and country.

Like all other issues involving animals and their care, the safe and humane housing of livestock and poultry is complicated and requires a careful analysis of a multitude of factors to determine what is best for animals, the people who care for them, the public and the environment.