By: Eric Dorr of Novel Feed Technologies
Spring is finally here, which means that first cutting harvest is rapidly approaching. Wilted forages that are harvested for silage such as grass and alfalfa can often present a nasty challenge to overcome. That challenge is when Clostridial organisms dominate the fermentation race and they produce butyric acid in the silage. Butyric acid is not only extremely stinky and unpalatable for cattle, but it can come with health concerns as it is produced by Clostridial organisms which could potentially infect cows.
The Clostridial spores in the silage actually come from soil that the crop is grown in. When we swath and wilt the forage, we lay it on the ground in direct contact with the soil. As we attempt to dry and move the crop by raking and merging, we can mechanically incorporate more dirt contamination into the windrow. This necessary management step unfortunately increases our risk of Clostridial contamination. Another risk is the moisture content (or rather dry matter content) of the crop itself. Wetter silages have a higher risk of going butyric than dryer silages. This risk can be compounded when the chance of rain forces one to harvest earlier or to shorten wilting times. The wetter the feed, the more likely that Clostridia will grow during the fermentation. Wilting to a higher dry matter (>40%-45% DM depending upon the crop) can almost eliminate the risk of a butyric fermentation.
These risk factors are real. If not controlled, they can result in poor fermentation and feed that is not only unpalatable and unproductive, but also damaging to cow health. Understanding the cause and effect of these factors is key to developing effective protocols that help reduce or prevent the risk of Clostridial silage.
Probably the most important management decision is to wilt the crop to a higher dry matter. If you consistently find butyric acid in your silage, consider increasing wilting time. Next, focus on limiting soil contamination in your feed. It may be time to upgrade your raking equipment or consider using a merger. Be sure to check the ash content on your silage analysis report. If your ash content is higher than average, then dirt contamination is your additional ash.
There’s no sense in bragging at the coffee shop about the tons you made if the cows won’t eat the feed. Knowing that the problem stems from undesirable contaminants dominating the fermentation process, consider controlling fermentation with the highest quality inoculants available.
A drop in pH to below 4.5 as quickly as possible is vital to outcompeting Clostridia in the fermentation race. A key factor in achieving this is speed and the rapid removal of oxygen from silage. While physically removing oxygen by packing is critical, there are a few modern silage inoculants that also include oxygen-scavenging bacterial strains that have changed the market. If you are still in the “all inoculants are the same” camp, you are not doing your forages any favors.
Phoenix Feeds and Nutrition is the only vendor in the Northeast offering inoculants with oxygen-scavenging technology that greatly enhances the fermentation process.
When faced with wet feeds and weather risk, the tendency is to operate as fast as possible. This is great—but only if we don’t compromise on packing time. One of the most crucial components to avoiding butyric feed is to have a high density silage. You have probably seen pockets and clumps of butyric feed in your silages when nearby silage is normal. These pockets are almost always the result of a rushed packing job, where a thick layer of feed is pushed up and not properly packed. The key to high density silage is to push and pack thin layers of feed. Trying to pack thick layers does not work, and butyric clumps are the result.
Even with all the right management decisions, the risks are still high. Small amounts or pockets of butyric acid can occur. It is wise to feed a daily probiotic such as Probac™ 6 to enhance the gut health of your cows and to directly combat pathogens such as Clostridia that may occur.
Ultimately, preventing butyric silages is not impossible, but it requires attention to detail and a strong understanding of the risks.
Have questions or want to improve your approach? Reach out to your Phoenix Feeds and Nutrition representative. We are here to help.