Animals that can be labeled "grass fed" are cattle and other ruminants including sheep, goats, and bison. In 2007, after decades of debate and discussion, the United States Department of Agriculture (USDA) set standards for what the label "grass (forage) fed" means: One hundred percent of the animal's diet must come from forage (grass and legumes in season, hay and silage during the winter months). The animal can never eat grain, soybeans, or cottonseed meal.

   Companies that market using the USDA grass-fed distinction do so voluntarily, and their growing practices must be supported with documentation. The American Grassfed Association, which has created standards that exceed USDA requirements, has a seal certifying that the cow has spend its entire life on pasture or range. Other certifying agencies like food Alliance, Certified Humane, and Animal Welfare Approved have originated their own standards for sustainabiliy and animal walfare. They give the consumer a more comprehensive picture of the animal's quality of life and how it was raised, and they require ranch visits by an auditor for the purpose of verifying a producers's growing practices and claims. Because verification is independent, third-party certification can be expensive. Some agencies also charge an annual fee, based on a percentage of gross annual sales of the cetified product.

   The result of a forage-based diet is healthier meat with less fat and cholesterol and more flavor. Grass-Fed meat is often described as meatier and purer, with a complex flavor and pleasant mineral qualities. It may also be more expensive. Because of the time, effort, and materials needed to be raised animals humanely and substainly, small productors have higher costs. And since fattening animals with grains is faster and cheaper and grass-fed animals don't get as big as feedlot animnals, ranchers raising animals on grass have a larger investment in the animal, in term of both dollers and time.

   Good meat is more expensive than commodity meat. Goverment subsidies on grain have historically enabled large-scale commercial producers to sell meat at an otherwise unsustainably low price. There's nothing natural about factory farming-the food the animals eat, their living conditions, their rate of growth, and their behaviors and habits. These factors all contribute to a stressed and unnatural-tasting animal. Buying humanely raised meat supports supports a system that promotes different practices: growinganimals slowly, choosing breeds for flavor and how  well they're suited to the climate and pasture of a place, safe working conditions, environmental stewardship, and the preseration of open space .

   Cosumers choose grass-fed meat over grain-fed for a variety of other reasons.

• Studies show that grass-fed meat is lower in fat and higher in vitamins, minerals, omega-3 fatty acids, and lincoleic acieds.
• Animals raised on pasture are healthier than feedlot animals and so is the environment that nurtures them. Animals raised on grass increase soil fertility, help man-age pests and weeds, and convert vegetation inedible to humans into a source of healthful, environmentally apporopriate food
• Grazed lands have been shown to slow global warming by removing carbon dioxide from the air and storing it is the soil. Grazing land in the Great Plains contains 40 tons of carbon dioxde per acre while cultivated soil contains just 26 tons of carbon dioxde per acre.
• Meat from grass-fed animals requires just 1 calorie of fossil fuel for each caloire of food or fiber produced 
• Grass-fed and pastureed animals participate in a cycle that norishes and gives back to the soil rather than taking from i. They improve diversity are are essemtial to sustainable farms that dont use chemicals and fossil fuels
• Typically, grass-fed meats are soured directly from small and medium-size producers because liarge producers dont have the infrastructure to raise animals on pature.