Sickening reports released recently from an investigation of two large egg-producing farms in Iowa would shake anyone’s confidence in the safety of America’s food supply.

Federal Food and Drug Administration inspectors were drawn to the farms following a salmonella outbreak that prompted the recall of half a billion eggs produced in Iowa.

What they found was a situation that many Americans wouldn’t think could exist in this country. Barns where eggs were being produced had dozens of holes chewed by rodents that allowed mice, insects and birds to enter and live inside the barn. Manure piles had built up to 4 to 8 feet high in pits below hen houses sometimes pushing pit doors open allowing more rodents and wild animals to enter. Dozens of hens had escaped their cages and were roaming free, tracking manure as they went. Even the water used to wash the eggs before they were sent to market was found to be contaminated with salmonella.

The FDA also announced that this month, it would begin inspecting the nation’s 600 largest egg farms, which produce 80 percent of the nation’s eggs.

It’s about time.

The fact that just 600 farms produce 80 percent of the nation’s eggs may be part of the problem. In 1987, there were about 2,500 commercial egg-producing farms, according to United Egg Producers, a trade group. Now, 192 large, profit-driven commercial egg producers control 95 percent of all the nation’s laying hens; half the nation’s hens are concentrated in just five states.

Iowa is by far the largest egg-producing state. It is perhaps not surprising that, according to food safety experts, Iowa also has far fewer rules than most states regarding inspections of food and feed operations and therefore produces some of the least expensive eggs in the country. You get what you pay for.

Particularly maddening about the current situation is that so many of the violations inspectors are finding now could have been so easily detected by anyone taking a stroll through the farmyard. The fact that they weren’t discovered until there was a major salmonella outbreak casts real doubt on the regulations and regulators that supposedly ensure the safety of America’s food supply.

In recent years, several outbreaks of food-borne illness have been traced to produce that came from Mexico or other locations outside the U.S. Many Americans may have smugly thought that “buying American” would protect them from such dangers.

Well, think again. Ensuring the safety of the American food supply should be a basic responsibility of government. Consumers deserve — and must demand — better.