What are the key things to remember in making good silage?

Adequate levels of water-soluble carbohydrates (WSC), low buffering capacity, appropriate moisture levels of forage, packing and sealing oxygen out of the pit, pile or bag.

What do I need to know about water-soluble carbohydrates (WSC)?

Generally a minimum of 6 to 12% WSC is required for silage to ferment properly. If a forage is nearly dry enough to make hay, (15 – 18% moisture), and gets wet again, the water-soluble carbohydrates remaining in this forage is lower and may not be adequate to make good silage.

What are some average WSC levels in commonly grown forages?

  • Alfalfa
    • Vegetative stage – 9%
    • Full bloom – 7%
  • Legume grass mix (50:50) – 13%
  • Barley
    • Flowering – 18%
    • Milk stage – 32%
    • Soft dough – 24%
  • Orchard grass – 6%
  • Reed canary grass – 7%
  • Brome grass – 9%
  • Timothy – 10%
  • Quack grass – 13%

What is the buffering capacity of a forage and how does it affect WSC?

Plant proteins increase the buffering capacity of silage. The higher the buffering capacity of forage, the longer it takes to ensile and more WSC are required. Legumes generally have a high buffering capacity, requiring a higher percentage of WSC to ensile properly.

  • Legumes with a high buffering capacity require about 10 – 12% WSC to ensile.
  • Grasses with a moderate buffering capacity require a minimum of 6 - 8% WSC.
  • Beet pulp with a low buffering capacity requires only 4 – 6% WSC for good preservation.

What is the best moisture level for making silage?

The optimum moisture level for pit silage is 60 to 65%.

The optimum moisture level for wrapped bale silage is 50 to 55%.

What forages make the best silage and why?

Cereals make the best silage because they generally have low buffering capacity and high WSC. Alfalfa is much riskier to ensile because of the high buffering capacity and lower levels of WSC. There is more room for error when putting up barley silage. There is no room for error when putting up alfalfa silage.