Dairy Excell: Are you producing top-quality silage?


Producing top-quality silage is certainly a goal of every dairyman. Bill Stone, veterinarian from Cornell University, presented forage management goals at the recent Northeast Ohio Dairy Management Conference in Canton.

Since feeding adequate quantities of high quality forage is the basis of profitable milk and livestock production, please consider the forage management ideas shared below.

Characteristics of quality.

To produce quality silage, producers should set forage quality goals, predict alfalfa maturity, learn fermentation basics, consider proper windrow width be aware of dry matter levels at harvest, understand chop lengths, investigate using inoculants, use proper packing techniques, cover properly, and use correct cutting intervals.

The characteristics of quality silage include; N.D.F. (neutral detergent fiber), dry matter, odor, and particle length. Alfalfa silage should have 40-44 percent N.D.F., with 34-40 percent dry matter in a bunker, or 34-45 percent dry matter in a bag. The silage should have little or no odor at a distance, with a slightly sharp sense up close. Particle length should be such that 12 percent of the TMR stays on the coarse upper screen of a Penn State Particle Separator, Producers should remember that 5/8 of an inch recommended cut length of silage means that many pieces will be more than an inch long.

Stone shared a chart showing the relationship of alfalfa maturity to possible milk production. Dairyman feeding at least 45 percent pre-bloom hay have the potential for milk production to reach 95 pounds per day, feeding 45 percent early-bloom hay topped out at 84 pounds per day, 45 percent middle bloom hay put the level at 70 pounds per day and finally full-bloom hay was also at 70 pounds per day. The moral of the story, cut your hay early and often! If we use Growing Degree Days to predict when to cut our alfalfa, then 700 GDD puts us at 40 percent Neutral Detergent Fiber. On average we reach 700 GDD at the Akron Canton Airport from May 18 to the 25.

Harvest and fermentation.

Silage fermentation has a less than one day aerobic (oxygen present) phase followed by another less than one day lag phase and by the end of the second day fermentation should be starting. Hopefully it will reach its peak at five to seven days and reach a stable phase by 14 days. The secret to good fermentation is proper packing, correct maturity (young) and proper chop length.

Windrow width and height affects the dry matter and sugar levels of the hay, depending on where in the windrow the stem or leaves are located. Basically, we want a fast dry down in order to have more sugar and to have higher quality silage. Until the plants dry down, they continue to metabolize or “use up” the sugars you are trying to preserve for your cows. Therefore, we need to cut hay, in the morning using a wide flat windrow or no windrow at all, raking it after the drying process has started, Rake late in the evening or early morning when the dew is on or with moisture on the bay to hold leaves.

Dry matter level at harvest is critical for the fermentation of alfalfa. At dry matter levels below 35 percent, the alfalfa plant does not have enough available sugar to complete the fermentation process, Producers need to be aware of how quickly alfalfa hay can dry down. While waiting to be chapped, forage quality can be lost in a hurry. Grass hay can go as low as 20 percent DM and field corn 17 percent and still have enough sugar for fermentation.

Particle size considerations relate directly to fermentation and sugar availability. Too long of a chop can reduce fermentation due to difficulty in removing the air (silage does not pack tightly enough to eliminate air). Less sugar is available for the fermentation process forages with larger particle sizes.


Inoculants potentially have the greatest economic benefit when used on the first and fourth outting. Farmers should be using liquid inoculants and be applying them at the chopper- Always ask the inoculants company for research and quality control procedures for applying the inoculants. Finally make sure you keep the bugs alive, and remember inoculants, increase your chances of adding value to your silage, but they do not guarantee it.

Bunker management.

To determine if you have enough packing weight for a bunker silo, divide the packing vehicle weight by 800, The result gives you the tons of haylage you can adequately pack per hour into the silo. An example would be a 25,000-pound tractor divided by 800 gives your 31 tons per hour. You can pack a little more corn silage per hour. When packing use a progressive wedge, pack constantly, use multiple tractors if necessary, pack in shallow layers, and try not to disrupt packed silage.

When covering your bunker, make sure to cover immediately when finished. Always cover the pile when rain shuts down the harvest. You will need to make sure you have a high enough tire density, if using tires, to hold down the cover properly.

Manage your cutting interval, start early and cut every 28 to 34 days, It is best to leave 42 days or more between the third and fourth cutting to assure good stand life if you plan to use the field for hay next year.

In summary, top notch forages are an essential component of high production and cow health. Silage making is a complex anaerobic fermentation process, but the manager has control of most of the system. Good luck this spring, may the sun shine when you want it to and may it rain when you need it!

(The author is an agricultural extension agent in Stark and Summit counties. Questions or comments can be sent in care of Farm and Dairy, P.O. Box 38, Salem, OH 44460.)


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