Several news stories that were not widely reported suggest consumer preferences are changing the way food is produced in the United States. Even if the moves fall short of what some might like to see, it’s clear that large corporations are reacting to consumer concerns over how animals are raised for food production.

Health experts have in recent years expressed concerns over widespread use of antibiotics in factory farm operations raising chickens, cows and pigs. The fear is that the practice is creating a potential public health hazard — germs develop immunities to antibiotics because of the low-levels found in the meat human eat.

Industrial farming operations routinely give animals living in cramped quarters low doses of antibiotics to keep them from getting sick. The steady diet of antiobiotics helped the bottom line because the animals put on weight faster, shortening the time from birth to processing.

The public was paying attention to the antiobiotic stories and began to shop for antiobiotic-free meat. Sensing the trend, grocery stores pressed poultry producers in particular to stop the overuse of antibiotics.

Just last week, the New York Times reported that Perdue has dramatically cut its use of antibiotics. It turns out that slashing antibiotics use in industrial-scale livestock operations is not as simple as just stopping. Perdue reportedly spent nearly a decade working with its scientists to develop new methods of growing chickens — from egg to processing — that allowed antibiotics to be cut without reducing production.

The poultry industry has also been pressured by major customers, including fast food giant McDonalds, which announced in March that over the next two years the chicken meat it serves will not have been treated with antibiotics that could impact human health. McDonalds’ is eliminating only antibiotics that are also used to treat humans. Still, it’s an important step.

The move by McDonald’s will have a huge impact on the industry because of how much chicken it buys. But the fast-food chain is years behind fast-growing competitors Panera and Chipotle, who have been promoting antibiotic-free chicken on their menus for years.

Antibiotics in chickens and other livestock is a public health issue. And as the public became aware of the dangers, consumer behavior pressured the industry to change.

But public pressure is not limited to health issues. Many people who eat meat want humane treatment for animals raised for food.

Public reaction to chicken cages in which hens cannot turn around, lie down or flap their wings led to a 2008 ballot measure in California mandating larger cages. Reports of large-scale pig farms confining sows to so-called gestation crates that prevent them from turning around have also caught the public’s attention and the practice has been banned in nine states.

Pictures of hens living their entire lives in a nine inch by nine inch cage led to change. Stories of overuse of antibiotics and the potential for deadly antibiotic- resistant bugs also led to change.

Pictures of sick cows that cannot stand being carried by a forklift to a processing line or of pigs or chickens being brutalized also have an impact — and put pressure on farming operations to change their methods, even if only a few bad actors are abusing animals.

Pictures have an impact in reducing abuse of animals and for that reason it was encouraging last month when a federal judge in Idaho ruled that the state’s “ag gag” law, criminalizing the filming of an agricultural operation without permission, was unconstitutional.

The factory-farm industry fights any restrictions on operations, and regards animal activists as vandals and criminals. But if consumers demand change, then big buyers of chicken, beef and pork, such as McDonalds, Burger King, Costco, Wal-Mart and others will demand change — and the food production industry will have to change.

Anyone who eats meat has to accept certain unpleasant realities about food production — animals are killed. But that does not mean that animals grown for food should not be treated humanely while they are living.