🌾 Compound feed

Compound feed (mixed feed, formula feed) is a ready-made blend of plant and animal products fed to an animal as a complete ration; vitamins and minerals may be added. A feed mill balances it for one species and one stage of life, so a calf, a dry cow and a cow in milk each get a different recipe.

Grain does most of the work. FAO's figures from the early 1990s put cereals at over 60% of all concentrate feed in the world, and more than half of that cereal was maize. Protein comes mostly from oilseed meal and cake, which is what is left when seeds have been pressed for oil. Soybean meal is the biggest, at over 60% of the oilmeals. Vitamins and minerals go in through a premix, where tiny amounts are blended into a carrier first so they spread evenly.

You will meet it in three shapes. Mash is a loose meal. Pellets are pressed through the holes of a die and cut to length. Crumbles are pellets broken back into small grains.

For a dairy cow it sits next to grass, hay and silage. On intensive dairy farms concentrates make up over 30% of the diet; in intensive grazing systems in temperate Europe and North America, 20–30%. FAO's example of a UK dairy ration: 40–50% milling by-products from cereals and about a quarter oilmeals. Around a fifth is other things such as molasses and sugar beet pulp, and 10–15% is whole cereals.

Concentrate and compound feed are not the same thing, though the words get mixed up. A concentrate is a feed high in energy and low in fibre, like corn, barley or soybeans, often used as a supplement to something else. Compound feed is the finished recipe built from such parts. It can be mixed on the farm, but most published figures describe factory-made feed. Mills also make dietetic feed for stressed animals and medicated feed, which only a veterinarian can prescribe.

So when you read about milk from a large dairy farm, part of the story is what came out of the feed mill. For how cows are fed in general, see feeding.