Feed Lot Magazine Online, Proper Silage Management Increases Forage Preservation

Volume VII Number 5

September/October 1999

Proper Silage Management Increases Forage Preservation

Advances in silage technology have made it a principal way for cattle producers to preserve forage, according to research from Kansas State University (KSU). Several factors influence the quality and nutritional value of silage. They include crop species, type of silo, weather conditions at harvest and feedout, and additive use. However, the two dominant features of silage are the stage of maturity of the crop being ensiled and the management knowledge of the silage maker.

Silage Additives

Silage preservation has been enhanced by additives throughout the 20th century. Additives can be divided into three general categories: fermentation stimulants, such as bacterial inoculants; fermentation inhibitors, like sulfuric acid; and nutrient sources, including molasses.

Crops ensiled with an effective bacterial inoculant ferment faster and more efficiently and are chosen for properties including rapid growth under a wide range of temperatures and moisture conditions, low cost, and no residues or environmental problems.

Enzymes, another fermentation stimulant, are capable of degrading plant cell walls and starch, which can provide additional sugars for fermentation to lactic acid. This increases the nutritive value of the ensiled material.

Silage Additive Research at KSU

The department of animal science and industry at KSU began evaluating silage additives in 1975. Their research indicates inoculated silage had faster, more efficient fermentation, greater dry matter recovery, and improved feed to gain ratio, indicating inoculants are sound investments for producers who make and feed silage.

Silage Protection

Covering horizontal silos can minimize silage nutrient loss. One method of covering silos is with polyethylene sheets and using soil or tires to weight it down. This will help the degree of anaerobic conditions achieved and maintained during the fermentation and storage phases. Substantial losses can be incurred by not sealing silage, according to researched-based calculations.

Important Points

A corn hybrid should have a whole-plant dry matter content of 30 to 36 percent when the kernel is in the 60 to 80 percent milk-line stage of maturity.

Grain sorghum compares favorably to corn as a whole-plant silage and should be harvested at the mid- to late-dough stage of kernel maturity.

For corn, sorghum and small cereal grains, it is probably better to harvest too early rather than too late.

Whenever possible, very wet grasses or legumes should be field-wilted before ensiling.

The proper bunker, trench, or drive-over pile silo size is determined by the amount of silage to be fed daily and the amount of crops to be ensiled. The dimensions should be small enough to allow a rapid progression through the silage mass during the feedout phase.

Losses in very good silage range from five to 15 percent, with losses in very bad silage ranging anywhere from 25 to 50 percent.

The type of silo does affect silage quality, but high quality silage can be achieved in any type of silo that is well managed.

The silage face should be maintained as a smooth perpendicular surface to the floor and walls to minimize the surface area exposed to the air.

Silage effluent is very nutrient-rich and can pose an environmental hazard if it is allowed to enter a watercourse.

Causes of problematic silage include: delayed filling, forages ensiled too wet or too dry, chop lengths are too long, inadequate sealing of the ensiled forage, slow removal of silage during the feedout phase, aerobically deteriorating corn silage, failure to apply an effective bacterial inoculant

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