By Howard Blalock, Ph.D
The growing season in 2018 was quite diverse across the Midwest, upper Midwest and Eastern United States in particular. Across these geographies, we saw everything from drought to near-perfect growing conditions with the addition of late harvest due to a very wet fall. I think it is safe to say that it was at least interesting. Even though there are some spectacular corn and corn silage out there, we have seen severely elevated yeast counts in many corn silage samples across the upper Midwest and Eastern U.S. Yeast and/or mold utilize nutrients that otherwise would have been available to the cattle but once the feed is put up, you can’t really do much about that aspect.
High yeast feeds aren’t anything to panic over but they should be monitored. The initial result of feeding too much of a high yeast feed would be a reduction in DMI as the rumen is being impacted. Rumen function, and ultimately performance, would be jeopardized under these situations. The secondary effect of high yeast counts is that it is often followed by greater mold prevalence. If high yeast counts were found in your feedstuffs, you may consider running a mold count approximately 60 days after the feed was put up for storage. If you see elevated mold counts and you have questionable cattle performance/intake, I would suggest also running a mycotoxin screen on the feed. These values should provide enough information to your nutritionist to help you determine the best way to utilize the feed in question.
So, how do you utilize the feeds in question? First off, dilution is typically the best solution. A healthy rumen can handle a lot as long we keep it within reason. You may also consider using a yeast extract product such as Celmanax or LiquiPro Yeast Extract as these products help to provide the right conditions to handle high yeast and or moldy feed. A TMR preservative could also be considered under extreme conditions, especially where heating of the TMR becomes an issue. If the prevalence of mycotoxins is beyond control through dilution, you may need to consider the use of a toxin binder of some kind. Most of the time, these types of issues can be mitigated by properly balancing diets with these aspects in mind. Dilution being the solution. Focus on rumen stability and health (timely feeding, good bunk management, proper mixing, etc.)
If you have any questions regarding your particular feedstuffs, contact your local QLF Representative.