What do you Feed your Cows?

We asked the farmstead cheesemaker because we had heard much in cheese circles about milk from grass-fed cows. "Grass-fed" seemed almost a buzzword, increasingly applied to meats, milk, and products made from them. We had to admit that the term conjured up images of cattle munching on tasty plants in verdant pastures. Of course in most places the grass isn’t green all year, so there must be more to the story.

“Our cows are grass-fed,” she told us, adding “but of course they eat other things too.”

"Do you feed them silage?” We asked, knowing it is usually made from corn stalks and leaves in the familiar tall cylindrical silos or the in-ground pits covered with plastic sheeting and old tires.

“Yes,” she said, “bacteria in silos partially digest the rough plant materials, making them more digestible, and also tasty and slightly intoxicating. Our cows love it. It is a fermentation, just like the magic that produces cheese from milk.”

We hadn’t heard about “haylage.” Grass cut while still green and moist is stored in large, plastic wrapped bales, where the trapped moisture and shortage of oxygen also support fermentation, producing another nutritious, easily digested, and attractive food for cattle. She said that they are sometimes fed other materials. She mentioned peels and pulp left over from juicing oranges, noting that this and other feeds are adjusted as needed to ensure that the cows' marvelous ruminant digestive systems are working properly.

We were left puzzled by the meaning of grass-fed, and looked to the USDA for guidance. They weighed in in 2007 with the following definition, which when read carefully appears to exclude only mature grains such as corn and soybeans. According to the USDA:

"Grass and forage shall be the feed source consumed for the lifetime of the ruminant animal, with the exception of milk consumed prior to weaning. The diet shall be derived solely from forage consisting of grass (annual and perennial), forbs (e.g., legumes, Brassica, browse, or cereal grain crops in the vegetative (pre-grain) state. Animals cannot be fed grain or grain byproducts and must have continuous access to pasture during the growing season. Hay, haylage, baleage, silage, crop residue without grain, and other roughage sources may also be included as acceptable feed sources. Routine mineral and vitamin supplementation may also be included in the feeding regimen. If incidental supplementation occurs due to inadvertent exposure to non-forage feedstuffs or to ensure the animal’s well being at all times during adverse environmental or physical conditions, the producer must fully document (e.g., receipts, ingredients, and tear tags) the supplementation that occurs including the amount, the frequency, and the supplements provided."