That’s $1.1 to $1.3 billion in feed inventory “down the drain.”
Dry matter losses influence nutritional value of silage. For example, if two silages are made from the same crop, the silage that has a 10 percent DM loss will have a higher nutritional value than the silage that has a 20 percent DM loss.
The good news is that it is possible, with proper planning, attention to detail and a well-prepared silage team, for beef producers to achieve significantly higher DM recoveries.
But a practice that producers control but sometimes poorly implement or overlook entirely is properly sealing/covering bunker silos and drive-over piles.
Another problem associated with not sealing bunkers and piles or not sealing them properly is the visible, surface-spoiled silage created by months of deterioration.
What do a lot of beef producers do with this visible spoilage? They mix this poor-quality silage with good-quality silage and it goes into the ration along with all of the other feedstuffs.
So what effect does feeding poor-quality, surface-spoiled silage have on the performance of growing cattle?
Research conducted at Kansas State University shows that feeding surface-spoiled corn silage has a significant negative impact on the DM intake and nutritive value of a silage-based, growing ration.
In the Kansas State University trial, the original top three feet of corn silage in a pilot-scale bunker silo was left unsealed for the first 90 days post-ensiling, and the surface-spoilage was fed to steers fitted with ruminal cannulas.
The four rations compared in the trial contained 90 percent corn silage and 10 percent supplement (on a DM basis), and the proportions of silage fed were:
- 100 percent good-quality silage
- 75 percent good-quality, 25 percent poor-quality from the original top three feet of silage in the bunker
- 50 percent good-quality, 50 percent poor-quality from the original top three feet of silage in the bunker.
- 25 percent good-quality, 75 percent poor-quality from the original top three feet of silage in the bunker
The good-quality corn silage was made in a 9-foot diameter bag from the same crop on the same day as the silage in the bunker silo.
The poor-quality corn silage in the original top 18-inch layer of silage had a final depth of only about 7 inches and was quite typical of silage that had undergone several months of deterioration in the presence of air and water (Image A).
It had a foul smell, was mostly black in color and had a “mud-like” (slime) texture.
The extensive deterioration during the first 90 days of storage produced very high pH, ash and fiber values.
The corn silage from the original bottom 18-inch layer of silage had a final depth of about 15 inches and had an aroma and appearance usually associated with wet, high-acid-content corn silage (i.e. a bright yellow color and a very strong acetic acid smell).
The proportion of the original top 18-inch and bottom 18-inch layers of corn silage in the composite surface-spoiled silage was 23.8 percent and 76.2 percent, respectively.
The amount of “slime” surface spoilage was 0, 5.4, 10.7 and 16 percent of the DM in rations 1 through 4, respectively.
Results from the trial showed that the addition of surface-spoiled silage to the ration had large negative associative effects on DM intake and organic matter (OM), neutral-detergent fiber (NDF) and acid-detergent fiber (ADF) digestibilities (Table 1).
The first increment of spoilage had the greatest negative impact.
Rumen evacuation revealed that surface-spoiled silage severely damaged the integrity of the forage mat.
The results clearly showed that feeding poor-quality, surface-spoiled silage reduced the nutritive value of corn silage-based growing rations more than was expected.
The results from the Kansas State University trial also show there are both intake and nutritional benefits to feeding only good-quality silage.
But what is the economic impact of feeding poor-quality, surface-spoiled corn silage for a growing cattle operation?
The predicted combined effect of silage management and feeding practices associated with poor-quality, surface-spoiled corn silage is presented in Table 2.
Cattle fed good-quality corn silage, ration 1, had a DM intake of 17.0 pounds and an average daily gain of 2.25 pounds.
The DM recovery was 87.5 percent of the crop ensiled for the bunker or pile of good-quality corn silage.
Performance of cattle fed ration 2 assumed that only DM intake was negatively affected by creating and feeding 2.7 percent “slime” spoilage.
This produced 2.8 pounds less live weight gain per ton of crop ensiled, and the value of this lost gain was $3.92.
Performance of cattle fed ration 3 assumed that creating and feeding 2.7 percent “slime” spoilage also negatively affected the NEg of the ration and silage DM recovery in the bunker or pile.
This produced 12 pounds less live weight gain per ton of crop ensiled, which had a value of $16.80.
Performance of cattle fed ration 4 assumed that the NEg of the ration and DM recovery in the bunker or pile were further decreased and this produced 20.4 pounds less live weight gain per ton of crop ensiled and the value of this lost gain was $28.56.
The up-side is clear: Silage management practices that prevent surface spoilage benefit a beef cattle operation’s bottom line by increasing silage DM recovery and improving rate and efficiency of gain.
It’s estimated that a cattle operation that goes from the scenario described for ration 3 to the one described for ration 1 could increase the value of live weight gain produced per 1,000 tons of corn silage made in a bunker or pile by as much as $16,800.
When looking to properly seal silage in bunker silos and drive-over piles, select an oxygen-barrier film.
Research shows that oxygen-barrier film reduces the DM loss in the outer 1.5 to 3 feet of silage by 50 percent or more compared to regular silage covers.
In addition to being economically better for your silage program, it also is safer for you and your employees.
It’s simply too dangerous to pitch surface spoilage off the top of many bunkers and piles. When used appropriately, oxygen-barrier film can reduce or eliminate the need to pitch any silage. 
For more information, email Keith Bolsen or call (512) 301-2281.
References omitted due to space but are available upon request. Click here to email an editor.
PHOTOS
TOP: In the Kansas State University trial, the original top three feet of corn silage in a pilot-scale bunker silo was left unsealed for the first 90 days post-ensiling. The poor-quality corn silage in the original top 18-inch layer of silage had a final depth of only about seven inches. The corn silage from the original bottom 18-inch layer of silage had a final depth of about 15 inches.
BOTTOM: When looking to properly seal silage in bunker silos and drive-over piles, select an oxygen-barrier film. Research shows that oxygen-barrier film reduces the dry matter loss in the outer 1.5 to 3 feet of silage by 50 percent or more compared to regular silage covers. Photos courtesy of Keith Bolsen.
