Last year, overall harvested forage acres were significantly reduced throughout the Midwest, according to Progressive Forage, leaving forage inventories lower than usual in 2018. As we look to this year’s alfalfa harvest, it may be more critical than ever to do the little things right to ensure you harvest as much dry matter (DM) per acre as possible.

Always some DM loss

Even under the best management, some DM losses will occur. However, as you can see in Table 1, poor management can result in excessive DM losses throughout the harvest process. Under the worst scenarios, University of Wisconsin-Extension has seen DM losses as high as 71 percent from poor field curing, harvesting, storage and feeding. That means, for every ton of forage DM standing out in the field, only 580 pounds ends up being consumed by livestock.

That’s not a sustainable or acceptable loss, but, with good management, you can avoid massive DM losses. Let’s look at some opportunities to save DM during the harvest process. Keep in mind, this is a dynamic process and one parameter may influence others.

Field curing

Minimizing field curing time will have a powerful impact on resulting DM losses. If curing time is prolonged, plant respiration is extended and energy and other nutrients are lost. Essential fermentation sugars are then lost and a chain of events is set off causing DM losses of up to 26 percent of the crop. Judicious timing of cutting as it relates to predicted weather helps, but, sometimes, that’s just not possible. Wide-swathing will reduce curing time, allow for a more uniform pattern of wilting in the windrow, and shorten the time of exposure to changing weather. Ideally, cutting and harvesting occur in the same day.

Harvesting

Moisture content of the feed at harvest will have a great impact on DM loss because it affects many of the factors we measure to evaluate success or failure of a stored crop. If feed is harvested too dry, good packing density and low porosity will be difficult to achieve, fermentation acids will be reduced, and feed stability will be compromised. Beyond DM loss, digestibility will likely be compromised. Harvesting too wet can cause seepage and nutrient loss in the effluent, and clostridial fermentation is of greater concern with wet feeds.

Harvesting at the right maturity and chop length will also reduce DM losses. While maturity and chop-length mainly influence feeding properties, they can also impact density and seepage.

In storage

What happens to a crop in storage is often dictated by how a structure was filled, packed and protected from oxygen. Fill each structure quickly to reduce exposure time, pack in thin layers of 6 to 8 inches and pack tightly. To achieve more than 15 pounds per cubic foot DM density, you’ll need plenty of pack tractor weight. You can find the ideal pack tractor weight for your operation with this equation:

(Tons coming off the field per hour) X 800 = Ideal tractor weight in pounds.

For example, if a 12-ton load comes in every 10 minutes, that’s six loads per hour multiplied by 12 tons, or 72 tons per hour. Multiply that by 800, and you’ll need 57,600 pounds of packing equipment on the pile or bunker at all times.

DM losses just under the plastic can be challenging. You can reduce DM loss in the top three feet of silage by 20 percent by using a layer of true oxygen barrier plastic, such as Silostop^® 2-Step. Cover as soon as possible, overlap plastic pieces by 4 to 6 feet, hold the plastic down with wireless sidewalls that touch each other, and secure all edges with double sidewalls or gravel bags.

Monitor the condition of all plastic surfaces and repair or replace immediately if you find a compromise. Remember, exposure to oxygen is the enemy, so patch any rips quickly.

At feedout

According to UW-Extension, 8 to 30 percent of a harvested crop can be lost at feedout due to spillage during handling, or spoilage on the feed face or in the feedbunk. Sometimes spoilage is difficult to monitor because it may not show up as black, moldy feed. Generally, if feed seems even slightly warm, such as 10 to 15 degrees F warmer than the ambient temperature, DM losses are occurring on the feed face or in the feedbunk.

Once again, some of the events leading up to feedout set the stage for heating and DM losses, such as poor density or very low moisture. Proper bunker or pile sizing is also important. Make sure the feed face is an appropriate size to remove at least 12 inches per day in the summer. Using a facer can also prevent DM losses by decreasing the surface area exposed to oxygen.

Inoculants

Inoculants can have an influence on reducing DM losses, but start with good management practices. Choose an inoculant based on independent research and proof, and one that will fit your forage program goals. Kansas State University research showed upfront fermenters improved DM recovery by an average of 1.6 percent. Vita Plus Crop-N-Rich^® forage inoculant with MTD/1 technology improved DM recovery by 2.1 percent. If alfalfa haylage is valued at $80 per ton as-fed, a 2.1-percent DM improvement results in $1.68 saved per ton. Application costs to inoculate is generally much less than $1 per ton.

If silage heating at feedout is a challenge, L. buchneri-based inoculants can be helpful. L. buchneri produces slightly elevated levels of acetic acid, a powerful antifungal, that help reduce yeast and subsequent mold and heating. Vita Plus Crop-N-Rich Stage 2 forage inoculant combines an upfront fermenter with a high dose (400,000 cfu per gram) of L. buchneri.

Although you can feel pressed during harvest season, slowing down to do the small things correctly can help save DM and lost dollars along the way.  

Jon Urness is with Vita Plus. You can view more forage-related articles on the Vita Plus Forage Foundations page.