What is Silage Time?
Silage time is one of the busiest and most important events on a dairy farm. It’s when surplus grass is harvested and preserved to feed cows during the winter months, when grazing isn’t possible. Here’s what happens during silage time:
The Silage Process
- Silage is usually made in late spring or early summer, once grass growth is strong and the first grazing rotation is complete.
- The goal is to harvest high-quality grass at the right stage — typically before it becomes too stemmy — to ensure good nutritional value.
- Silage is essential for feeding cows during the dry period (winter) when pasture is limited or unavailable.
- Fields are closed off several weeks in advance, meaning cows are kept off to allow the grass to grow.
- Farmers may fertilize fields with slurry or nitrogen to boost growth.
- Machinery is checked and serviced, and contractors may be booked in advance if the farm doesn’t do its own harvesting.
- When the weather forecast predicts a few days of dry, settled conditions, silage-making begins.
- Grass is mown, then left to wilt in the field for 24–48 hours to reduce moisture.
- It is then raked into rows and collected using a forage harvester (‘chopper’) or silage wagon.
There are two common ways to store silage:
- Clamp or pit silage: The cut grass is brought to a concrete pit (the clamp), spread in layers and tightly rolled to squeeze out air.
- Baled silage: Grass is baled into round or square bales and wrapped in plastic to ferment individually.
- In both cases, the aim is to create anaerobic conditions (no air) so the grass ferments properly and doesn’t spoil.
- Once sealed, the grass ferments over several weeks, turning into silage — a sour-smelling, moist, preserved feed.
- This fermentation process locks in nutrients and makes the silage stable for storage over winter.
- High-quality silage is crucial for maintaining cow health and body condition during the non-grazing season.
- On spring-calving farms, silage supports cows during their dry period and early lactation if grass is not yet fully available.
- It’s the second-most important feed after grass — and the best way to make sure cows stay productive year-round.
In Summary
Silage time on a spring-calving, grass-based dairy farm is all about capturing the goodness of spring and early summer grass to feed cows through the winter. It takes planning, good timing and teamwork — and the quality of the silage made can have a big impact on the farm’s success in the months that follow.