One reason why farmers are so busy in the summer is that they are having to grow most of the food that the cows and sheep will eat in the winter when nothing much grows.
Even though it’s the winter, the cows (and the bacteria in their rumens!) like grass. As any gardener knows, the grass doesn’t grow much in the winter so the cows need to be given grass preserved in some way – either dried (hay) or pickled (silage). Silage is a lot more palatable because it is moist and it is also more nutritious.
The key to making good silage is to exclude the air so that the carbohydrates in the grass ferment rather than decompose.
Grass may be ‘ensiled’ by packing it into a silo or by rolling it up into large bales covered with plastic to keep the air out. This favours the growth of acid-making bacteria such as Lactobacillus, and the weak acids they make preserve the grass and its nutrients. Another species of Lactobacillus plays a similar role in the making of yogurt and cheese.
Another form of silage is made using chopped maize plants and ‘wholecrop’ wheat. The maize and wheat are harvested using a ‘forage harvester‘. It gathers the crop in a similar way to a combine and then chops the plants and blows them into a trailer. The chopped plants are then put into a ‘clamp’ and packed down to exclude air by driving the tractor over them.
In addition to silage, which is largely composed of fibrous cellulose, farmers give their stock ‘concentrates’ to enable faster growth and milk production by providing extra protein and carbohydrates. Concentrates are comprised of rolled barley (which is home-grown), and soya bean and molasses which are bought in.
The maize/wholecrop silage, rolled barley, soya, and molasses are combined in a ‘mixer wagon’ and taken to the feeding areas. Judging by the eagerness of the cows, it’s pretty tasty!