A Guernsey calf. (Photo by Tricky.)

As heirloom produce gains a growing cult following among eaters, the more under-the-radar interest in heritage livestock breeds may see a resurgence, too. The first National Heirloom Exposition in California last month featured heritage farm animal breeds in addition to the fruits, veggies, and seeds that get foodies excited. Cheese devotees, especially, should take note — buying and enjoying cheese made from the milk of certain rare breeds of cattle helps ensure their survival. Over on the blog It’s Not You, it’s Brie, cheese enthusiast Kirstin Jackson collected notes from dairy farmer and veterinarian Dr. Noreen Dmitri. Here’s a condensed version what we learned.

Back in the day, before industrial agriculture was the norm, breeds like the Milking Devon, Ayrshire, and Randall Lineback had traditional uses on the family farm, and each produced cheese of a unique flavor. But many of these breeds are now endangered: America’s first cattle breed, the Canadienne, has a population of less than 500 worldwide, while Holstein cows, favored by industrial farms for their large size and milk production, number 19 million and account for almost 20 percent of U.S. dairy cattle.

As the market for locally and sustainably produced food has grown, small dairies and the heritage-breed cows they use have found new life. The American Livestock Breeds Conservancy in North Carolina is working to preserve the breeds, and the number of small dairy plants in New York State doubled in the past two years. Something called the Swiss Village Farm Foundation is also using embryo transplants to boost Canadienne reproduction.

Lovers of fine cheese should look for a “Heritage Milk” label when they shop. If you’re in the Midwest or on the East Coast, It’s Not You, it’s Brie’s Kirstin Jackson has also collected a great list dairy farms selling heritage-milk cheese.