Free-range poultry and cage-free eggs may command higher prices in the supermarket, but they offer consumers little or no demonstrable benefit in food safety or quality, animal health and welfare, or healthful food, a panel of scientists concluded after a review of a battery of research papers they called “inconclusive and often contradictory.”

Different outcomes in the 150 papers “make it impossible to make general statements with regard to the effect of free-range poultry production” on the factors studied by a task force assembled by the Council on Agricultural Science and Technology (CAST) and published in a paper released Wednesday in a series of briefings for industry and government in Washington.

The safety of poultry meat and eggs is determined more by management than by whether the birds are in confined facilities or outdoors, said the authors. Food safety is an important consideration with any production system. “The research on the bacterial loads of poultry meat from conventional and free-range systems has been very conflicting,” they said, affected by differences in location and the time of year.

Whether from free-range or conventional production facilities, poultry meat can carry risky pathogens, said report co-author Jacqueline P. Jacob of the animal and food science department at the University of Kentucky, and requires proper handling. “Always cook poultry to 165 degrees regardless of where it was raised,” said Ashley Peterson, senior vice president of scientific and regulatory affairs at the National Chicken Council (NCC).

The paper said microbial contamination on eggshells in both cage and free-range systems is comparable if facilities are managed properly. Both systems can produce eggs with pathogens “that even washing cannot decrease to a safe level,” it added.

Although many consumers believe that free-range poultry production is more conducive to animal welfare, “that has not been shown to be the case,” Jacob said. “There were reasons we put birds in cages. There were reasons we put birds in houses. It made it easier to manage,” making them safer from bad weather, predators and disease.

“When the industry began using cages, it took care of the birds’ physical needs,” said co-author Anthony J. Pescatore, a University of Kentucky Extension poultry specialist. “Now we are trying to balance that with the birds' behavioral needs” by giving them more room for behavioral stimulation such as pecking and preening. While increased space allowance may be seen to improve animal welfare, Pescatore noted that “there is actually more danger outside.” The paper described “increased risk factors that can adversely affect bird welfare” such as predators and exposure to disease.

Animal welfare is a concern for consumers in the low 20 percent range, according to David Fike, vice president, communications and consumer/communication affairs at the Food Marketing Institute (FMI), which hosted the briefing. Citing FMI research, he said the main driver for purchasing decisions is taste and quality for consumers in the 70 percent-plus range. “Consumers in the high 80s and low 90s are satisfied with food safety,” he said.

“The main conclusion that can be made with regard to the nutritional composition of poultry products is that it is more reflective of what the bird eats rather than the type of production system used,” the paper said. While outdoor access itself does not alter the nutritional content of the products, the authors said that the nutrient content of poultry meat and eggs can be enhanced by feeding on high-quality pastures. Some pasture-raised poultry products may contain higher levels of omega-3 fatty acids, “but we don’t know whether the levels are high enough to have any human health benefits,” Pescatore said.

Although very little documented research about the disease risks of free-range compared with conventional poultry production is available, free-range poultry may be more vulnerable to some diseases “but there is no indication that the presence of free-range poultry poses a risk to conventional poultry,” the paper said.

CAST’s report also said, “The research results regarding the environmental impact of different production systems vary considerably and are often conflicting. The main issues affecting environmental impact are manure management and feed formulation. Free-range poultry production requires more land at a time when there is high demand for agricultural land. There is considerable variation in farming systems used in free-range poultry production. This includes differences in farm size, housing and range availability, and opportunities for pasture rotation.”

Other authors of the CAST task force report were Kenneth E. Anderson of North Carolina State University, Brigid McCrea of Auburn University in Alabama and Daniel P. Shaw of the University of Missouri.

For more news, go to