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Bale wrapping: How late is too late?

Melissa Beck for Progressive Forage Published on 01 June 2017
Wrapping round bales

When it comes to bale wrapping, there may be a little more wiggle room for putting up a quality product than once thought – according to research at the University of Arkansas and the U.S. Dairy Forage Research Center in Madison, Wisconsin.

Weather conditions such as mild temperatures, frequent rains, heavy dew and overcast days make curing early-season hay difficult. Waiting for perfect conditions can result in forages that are too mature and lower in quality, and rains can contribute to diminished quality by essentially washing away the water-soluble proteins and carbohydrates.

These factors increase the appeal of baleage technology.

Silage bales allow producers to store high-quality harvested forage with diminished curing time in the field. Another benefit is the decreased storage losses when compared to traditional hay stored outside. Losses of hay stored outside can range from 20 to 50 percent, while the losses of baleage typically are less than 5 percent.

Round bale silage can greatly improve the timeliness of harvest, which in turn, can improve the quality of harvested forage.

When processed properly, baled silage is often higher in quality than similar hay because of reduced leaf loss in legumes, shorter curing time, reduced spontaneous heating and less weather exposure in silage.

Wrapping recommendations

Cody Askew, a cattleman and forage producer from southwest Arkansas, has been baling silage for five years. Askew says the biggest benefit is getting the hay out of the field without having to waste time waiting for it to properly cure. Askew says, “I have a lot of ground to cover and if the ryegrass and clover dry out too much, I will wrap what I can and bale the rest as a dry hay.”

It has been recommended that baled silage should be wrapped within two hours of baling, with moisture content of 45 to 55 percent. Anaerobiosis, or an oxygen-free environment, is required to produce well-preserved silage. Oxygen trapped in the bale at wrapping is removed through respiration of the harvested plant cells, and new oxygen is prevented from entering the environment by good wrapping.

Simply put, silage is a process of increasing good bacteria (lactic acid bacteria) and eliminating bad bacteria (clostridia, enterobacteria) by excluding oxygen. Plants with higher water-soluble carbohydrates (WSC) tend to make better silage. Another factor that contributes to quality is the buffering capacity of the forage.

Clostridial fermentation causes the formation of butyric acid and ammonia, both of which contribute to the bad smell associated with poor fermentation. Clostridial fermentation can be caused by moisture over 60 percent, high contamination with dirt and manure, low WSC in the plant, high buffering capacity of some plants, high protein, excessive legumes and not wilting the forage prior to ensiling.

When silage is exposed to air, either from poor wrapping or not having the bale rolled tightly, the bales go through a heat and the plant sugars are converted to CO2. This causes a loss in dry matter and decrease in total digestible nutrients (TDN).

If weather, equipment failure or other conditions prevent wrapping silage in a timely manner, there could be a decrease in the quality of the resulting forage. In one of his studies, Wayne Coblentz, a research scientist at the U.S. Dairy Forage Research Center, looked at what happens to fermentation when silage bale wrapping is delayed by one, two or three days. An unavoidable delay in wrapping your baleage doesn’t mean all is lost for a quality end product.

In Coblentz’s delayed wrapping study, large alfalfa round bales were wrapped four hours after baling or after delays of one, two and three days to compare the effects on fermentation and forage quality. The internal temperatures of all bales were collected at wrapping, and bales were sampled after being stored for 97 days.

The internal temperature at baling was higher in all bales with delayed wrapping, but increased with longer delays. Peak temperatures during the 97-day storage period also increased as the wrapping delay increased. The water-soluble carbohydrate content decreased with increasing delayed wrapping, which was related to the increased temperatures during storage.

The total silage fermentation acids were higher for bales that were wrapped immediately and these levels also declined with longer delays in wrapping.

In summary, wrapping delays did inhibit fermentation and decreased the nutritive value of the silage after the 24-hour mark, but there appears to be more forgiveness in that first 24-hour period than previously perceived.

Additional research

New research from University of Arkansas conducted by Ken Coffey seems to confirm that producers have more time to get a quality product baled and wrapped. Coffey says, “The most exciting thing to me was we got greater digestible organic matter intake from the alfalfa haylage that was wrapped one day after baling.”

Producers, however, don’t want to delay too long. Coffey’s research showed dry matter percentage in the silage increased with a two- to three-day wrapping delay and two to three days between baling and wrapping substantially decrease lactic acid (from 2.25 percent at no delay, all the way down to 0.8 percent with two-day delay and 0.6 percent for the three-day delay).

Research conducted at the University of Arkansas Southwest Research & Extension Center at Hope, Arkansas, reinforces the findings by Coblentz and Coffey. In a project conducted by graduate research assistant Tyler Crook, annual ryegrass was baled at either 30-percent moisture (too dry) or 74-percent moisture (too wet) and wrapped after zero-, one-, two- or three-day delay.

Internal temperatures of haylage baled too dry were higher and heating increased with delay – the higher internal temperatures caused molding and lead to increased fiber, decreasing TDN content of the forage. Lactic acid content of the haylage decreased with wrapping delays of more than one day and butyric acid content increased with longer delays too.

In terms of dry matter intake and digestibility, both increased with a delay of 24 hours between baling and wrapping, but then both decreased with longer than a 24-hour delay between baling and wrapping. Therefore in terms of the feed value of the silage bales, 24 hours or less is the sweet spot.

Jon Vaught, a cattleman from southwest Arkansas who owned a dairy for 13 years, has always waited 24 hours to wrap baleage. He says, “It has always been an issue of getting it done when we could get to it.” But forage tests between what he wrapped on the day it was baled and the next day weren’t appreciably different, and he never noticed any difference in intake and animal performance by waiting a day to wrap.

The disadvantages to baleage include the cost of bale wrapping (costing upward of $8 per bale) and the extra steps of handling bales for wrapping at the time of baling. Additionally, the plastic used to wrap bales is susceptible to being punctured either by equipment or animals and should be examined for damage periodically during storage.

Another consideration is the waste associated with baled silage; the plastic cannot be reused and recycling isn’t a good option due to the residues of dirt and low demand for recycling the material.

Round bale silage is another method to produce high-quality, low-maturity forage. When, however, circumstances prevent the immediate wrapping of silage bales, producers can inventory those lower-quality bales and use them to feed livestock with lower nutritional requirements.

Producers have about 24 hours to wrap bales in order to get good fermentation and a highly digestible end product; however, delays beyond 24 hours will result in incremental declines in silage quality.  end mark

PHOTO: Research continues to prove that producers have about 24 hours to wrap bales in order to get good fermentation. Anything beyond that will affect forage quality. Photo by Melissa Beck.

Melissa Beck
  • Melissa Beck

  • Freelance Writer
  • Prescott, Arkansas
  • Email Melissa Beck