Difference Between Hay and Silage


Main Difference

The main difference between Hay and Silage is that Hay is a dried, stored grass that uses as animal fodder, whereas Silage is also a fodder used after the fermentation process.

Hay vs. Silage

Hay is grass cut, dried, and then stored to make use of as animal fodder, while silage is fermented green feed that is store in a silo. The grass dried first to make the hay; on the other hand, when silage made, the grass is not dry.

Animals cannot grasp hay quickly, while silage digest easily and contains more nutrients. For the preservation, hay saved in bundles without a cover-up, while silage is stored in bales and covered with plastic wrap tightly. Hay dried in fields, but silage is not.


A crop with thin stems makes hay in 48 hours, but silage making process is complete within 21 days. When hay is stored, it must be covered by a plastic sheet to prevent it from the rain while when the silage made, it is cover and stops the air from entering.

Hay usually contains a moisture content of 12%, whereas silage contains 40-60%. The dry matter value of hay is 82%, while sillage has DM value 40-60%.

Comparison Chart

Cut and dried grass used as animal fodder is called hay.Fermented, green fodder, which stored in a silo, is called silage.
Sun-dried productFermented product
Moisture content is 12%Moisture content is 40-60%
Bales are store without a wrapBundles are store in plastic wrap
Dry matter value is 82%Dry matter value is 40-60%
Affected by weatherLess affected by weather
Dry in the fieldDry in tightly packed

What is Hay?

Preserved forage, which used as fodder made by mown grass, is called hay. Hay is grass, herbaceous plants, and legume are cut, dried, and stored. Use it as a pasture for livestock such as horses, sheep, cattle, and goats.

Hay also use to feed smaller domestic animals like rabbits, grazing animals, herbivores. Hay used as pig’s fodder, but they cannot digest it easily. Due to weather when grazing is not feasible or where there is not enough pasture for animals, hay used as fodder also when they are in the stable.

Making of Hay

Mowing of the grass crop is the first step in haymaking. In late June just before flowering, the making of hay starts usually. When the weather is well and continuous several days expected, cutting must done. It is affected by rain, becomes unpalatable and poor quality.

In the second step, cut grass will be dry in the sunlight. Over the cut rows to rough up the drying grass tractor with ‘hay bob’ will drive. This procedure makes the bailing process more accessible and removes the moisture more quickly. Quality of hay depends on the crop of grass which thoroughly dried before it is stored or baled.

A crop that can dry faster is suitable in the making of hay. Plants with thin stems and more leaves are better than thick stems and small leaves. It includes Maize, Oats, Disodium, Sorghum, Lucerne, Napier grass. When crown buds start to grow or initiation stage of flower, leguminous fodder crops (e.g., Lucerne, Cowpea, etc.) should be the harvest.

What is Silage?

The fodder fermentation process is silage. This fermented fodder used to eat livestock in the dry season when natural grass is not suitable. It is not dependent on the weather because the forage fodder stored in a silo. In the making of silage, more digestible material used.

To preserve its nutritional value, improve its taste, and quality, fodder will be pack airtight with polythene sheets. This process is entirely around 21 days. It contains many characteristics and heaving a pleasing smell.

Silage contains 40-60% moisture content. If it is too wet, then nutrients loss and spoilage of silage. If it is too dry, then it becomes hay. It is the main reason, bales wrapped in polythene sheets.

Making of Silage

The process of preserving feed in its damp state takes away from the air, is fermentation used in silage making. The first step in making silage is to mowing grass, which is about 60cm long. All mowers cut the plants into straight, known as swath.

A fodder harvester can pick up quickly. Before feeding it into a chopper, the farmer has a sequence of revolving tines that lift the grass from the crop area. After this process, the grinder cut it into a specific length, and the trailer used to transport into the storage area.

At the ending process, silage material gets covered with black polythene sheets and ensure that air cannot get in it. Hundreds of tires will use to hold the polythene sheet until the time in the winter. It is affected by wind and becomes poor quality silage.

Key Differences

  1. Hay is sun-dried forage, but silage is fermented forage.
  2. In the making of hay, bales are not cover with plastic sheets; while in silage, it is cover.
  3. Hay will be affected by the weather; on the other hand, the silage will not.
  4. Hay will dry in the field, but silage will dry in airtight.
  5. Hay will dry first and then made, while silage will dry in packing.
  6. Hay’s DM value is 12%; on the flip side, silage has value 40-60%
  7. Hay is affected by rain, but silage is affected by air.


Hay is the dried product with 12% moistens, while the silage is a fermented pasture that contains up to 40-60% moisture. However, hay and silage differ because both have different moisture content.

Aimie Carlson

Aimie Carlson is an English language enthusiast who loves writing and has a master degree in English literature. Follow her on Twitter at @AimieCarlson