The university study, the first known examination of how news coverage affects U.S. pork, poultry and beef demand, found increased coverage of pork and poultry animal-welfare issues from 1999 to 2008 reduced consumer demand.
Curiously, demand for beef those years showed no conclusive influence from news coverage, researchers Glynn Tonsor of Kansas State University and Nicole Olynk of Purdue University said in the Journal of Agricultural Economics.
It's possible "positive" and "negative" news about the physical and psychological well-being of cattle "canceled each other out, netting to be zero," Olynk told United Press International.
But if major U.S. newspapers and wire services had not increased their coverage those years, pork demand would have been 2.65 percent higher than it was and poultry demand would have been 5.01 percent higher, said the researchers, both agricultural economists.
Two big animal-welfare issues covered those years were gestation crates for female pigs and battery cages for egg-laying hens.
Gestation crates are 7 feet by 2 feet where pregnant breeding pigs are confined during pregnancy. Animal-welfare advocates regard these crates, in which the sows can lie down but not turn, as one of the most inhumane features of factory farming.
Conventional battery cages typically hold six hens packed tightly together, with each hen given slightly more than 8 inches by 8 inches of space. The tips of their beaks are often sheared off so they won't peck each other to death.
Smithfield Foods Inc., the largest U.S. pork supplier, said in 2007 it would phase out gestation crates by 2017.
Recent California legislation spearheaded by the Humane Society of the United States seeks to eliminate conventional battery cages starting in 2015. Michigan also adopted cage limits effective in 2019. Ohio will bar new battery-cage facilities but exempt current operators.