Food Safety Magazine just published an article Bailey Norwood and I wrote on animal welfare and food safety.
Here are a few excerpts:
The premise of [the movie] Contagion is that raising hogs on “factory farms” encourages the emergence of deadly pathogens. How accurate is this caricature? In reality, a bat is more likely to drop food near hogs or chickens raised outdoors. Would the movie have been more realistic if the bat infected a pig raised on an organic farm, a farm where animals roamed “free range,” or a farm owned by a small producer slaughtering his own animals and selling locally? Or would a more accurate film show the bat shedding feces near a field of broccoli, sickening people consuming fruits and vegetables instead of meat? Is it true that animal welfare and food safety are trade-offs, or are they instead complements? When we pay more for humane meat, are we also getting safer food or are we accepting greater risk? These are the questions we investigate in the present article.
Americans today consume more poultry than any other meat product so even if a meal containing poultry is safer than beef or pork, more illnesses may result from poultry consumption simply because chicken is consumed on such a large scale. Using the data in Table 1 to claim poultry is risky is a bit like claiming roads in Texas are more dangerous than those in Wyoming simply because more Texans die in car crashes—however, the population size of the two states would seem the more logical culprit. Analogously, the volume and value of the food should be taken into consideration when comparing risks. Consumers might voluntarily accept riskier food if they value it more.
and in summary:
In general, production systems that provide animals outdoor access have the potential to expose animals to pathogens, viruses and other parasites. In some cases, it appears that this potential is realized. However, in other cases, perhaps due to effects of lower stocking densities or better managerial competence, the risks can be alleviated or even reversed. In short, animal housing conditions are but one factor, and a far from deciding factor, affecting food safety.
However, consumers don’t always see it that way. Consumers conflate perceptions of safety with perceptions of animal welfare. They are not necessarily irrational in doing so, as care and managerial competence in one domain are likely to be correlated with meticulousness in another.