Silage: Production and Feeding – Part V

I have talked about silage for last couple of months in this column. My discussion so far has covered what is silage, what is a silo, the advantages and disadvantages of silage, crops commonly used for silage, the ensiling process and factors affecting silage quality.

Many factors, such as maturity stage of crops, type of stored crops, moisture content and length of chop, affect the quality of silage during storage, and at the time of feeding.

Today, I will continue the discussion on silage, looking at estimating quick moisture content and chopping length of silage, as well as preservatives and additives for silage.

For a quick estimate of moisture content in chopped forage, a simple field technique may be used. Below are some helpful tips for estimating moisture content. First, form a ball of chopped forage or silage in your hands and then observe the conditions of the ball.

The following observed conditions would tell us about the moisture content. If the ball holds its original shape and has considerable free juice, that represents over 75 percent moisture content of the silage. If the ball holds its original shape but has little free juice, the silage has between 70 and 75 percent moisture. However, if the ball falls apart slowly and has no free juice, this represents 60 to 70 percent moisture, and if the ball falls apart rapidly with no free juice, it has below 60 percent moisture.

When looking at the length of the chop, we have to consider the ensiling process. In the ensiling process, air exclusion is the first, and a very critical, phase. Finely chopped and adequately packed silage help to achieve this short phase.

In general, the length of chopped silage should be three-eighths to one-half inches. This length helps ensure appropriate fermentation through releasing juices of plant. This also allows better packing for exclusion of oxygen.

For improving silage quality, several investigations have been conducted and are ongoing. In certain situations, some additive and preservative products have proven to be beneficial.

For example, acid-forming bacteria seem to be promising as an additive, especially with early spring-cut and late autumn-cut haylage. However, products such as enzymes, yeast and antibiotics need to be further investigated.

It is important to give careful consideration before selecting any silage additives. No additives can replace or substitute the basic principles of making good silage, including harvesting at the right maturity stage, storing silage properly with the appropriate moisture content, fine chopping, proper packing and the right covering. Remember, as feed, silage can be no better than silage with additives added to the silo.

In the next article, I will continue this discussion on silo gases and their importance, followed by feeding of silage. Please keep an eye out for my next Extension columns.

Anowar Islam is an associate professor and the University of Wyoming Extension forage specialist in the College of Agriculture and Natural Resources Department of Plant Sciences. He can be reached at 307-766-4151 or mislam@uwyo.edu.