Retailers may soon start selling "animal compassionate" meat products.

Some food retailers are preparing to offer meat products that are touted to be from animals that were raised in loving environments. Whole Foods Market is preparing to roll out a line of meat that will carry labels saying "animal compassionate," indicating the animals were raised in a humane manner until they were slaughtered. The grocery chain's decision to use the new labels comes as a growing number of retailers are making similar animal-welfare claims on meat and egg packaging, including "free farmed," "certified humane," "cage free" and "free range."

While the animal-welfare labels are proliferating, it remains unclear whether they appeal to anyone other than a niche market of animal lovers, particularly since the meat and eggs are as much as twice as expensive as products that do not carry the labels.

The increase in animal-welfare labels has been driven in part by animal-rights organizations. The Humane Society of the United States, for instance, has been working for nearly two years to end the practice of confining hens to cages. But, like organic and natural labels, the animal-welfare claims are also a way for food retailers to offer something their competitors do not.

It's unclear whether consumers would be willing to pay extra for meat that comes from contented cows or happy chickens. "We went from four companies that are certified to 55," said Adele Douglas, executive director of Humane Farm Animal Care, which has a certification program. "These companies wouldn't be signing up if the products weren't popular."

The federal government generally does not regulate how farm animals are treated, nor do they verify animal-welfare labels. The government does require that labels be truthful and has established definitions for such designations as free range, natural and organic.