Forage harvester

While towed harvesters continue to be used by small-family farms, the more efficient way of silage-making is with a self-propelled machine with a tractor or truck running along with the forager.

Today's largest machines have engines producing up to 1,100 horsepower (820 kW), are fitted with headers able to cut up to a 35-foot (11 m) swath of corn in a single pass, and an output exceeding 400 tons of silage per hour.

Maize and whole crop silage are cut directly by the header, using reciprocating knives, disc mowers or large saw-like blades.

In most forage harvesters, the KP can be quickly removed and replaced with a grass chute for chopping non-cereal crops.

[6] Silage made from grass, canola, oats or wheat are chopped into 5 to 76 millimetres (0.2 to 3 in) pieces (depending on knife, cutterhead, and length of cut transmission configuration), and treated with additives including bacteria, enzymes, mold inhibitors, and preservatives to accelerate the fermentation process.