A century ago - The working horses on each farm consumed about 10% of a farms output. Working horses in towns and cities took another 10% of the national production, much of this being oats and hay. Maybe a third of all land was used for hay-making, where the dried grasses were stored and used to get the animals through the winter, and kale and beets were also grown as animal fodder crops. Even animals wintering outdoors such as sheep and beef cattle would need additional feeds to be in good health for lambing and calving, depending on the intensity of grazing. Pigs were generally fed on left-over food from hospitals and schools, chickens found what they could in the farmyard, though extra feed would probably produce more eggs and fatter chickens.
Nowadays, there are great changes:-
- Hay is seldom made in the old way - silage is made instead. This is an anaerobic fermentation process (similar to sauerkraut !) where less nutrients and mass are lost,
- It is possible to have a profitable agricultural business with a large shed of animals, using entirely 'bought-in' feeds, although many farmers still grow a percentage of their own fodder on economic grounds
- Horses are now almost entirely 'hobby' animals
- In Germany, 95% of dairy cattle never go outdoors ! The winters are too cold for them to be outside, the summers are too hot for them, so they have a "luxury life" in stalls all year, and this is now also happening to British dairy cattle. This decision seems to have been made about 40 years ago, and this has allowed the Germans to remove nearly all fences from their agricultural land, which is a great economic gain.
- Most feeds are 'compounded' by feed manufacturers to provide a balanced diet for the animals. They might typically be composed of grains, grass, molasses, malt, potato residues, other food processing residues
The general economics of animal farming are that the input of approximately 10 tons of grain or equivalent vegetable matter will produce 1 ton of animal protein (beef, chicken, milk product, etc.)