At the American Forage & Grasslands Council annual meeting earlier this year, forage experts presented a number of updates on baleage – and why it’s so important to do it right.
Looking at “Assessing Fermentation Quality and Botulism Risks Associated with Baleage,” Jimmy Henning, Extension professor in the Department of Plant & Soil Sciences at the University of Kentucky, presented research done by his team there.
“What’s your biggest fear when making baleage?” Henning asked. “Botulism. And it’s not for lack of good information.”
The ideal pH to avoid it is 4.5, but he noted that a lot of producers never get it that low. With that goal in mind, though, his team worked on a project that sampled various kinds of baleage and sent it to Dairy One at Cornell for testing.
Out of 129 total samples, the proper moisture levels were hit about 50% of the time; there was very low occurrence of ash; and there were good butyric and lactic acid numbers. “Farmers are doing things right!” Henning said.
As always, following the best practices for good baleage is crucial. Farmers want moisture content between 40% and 60%; tight, uniform bales; early cutting, if possible (for more water-soluble carbs, faster fermentation and that key pH drop); and to wrap quickly after baling, with six layers of plastic or more.
Additionally, those baling should have the following fermentation targets: a pH of 5.0 or lower; lactic acid at 3% or higher; butyric acid at 0.1% or lower; the percentage of nitrogen as ammonia at less than 15%; and the amount of ash lower than 8% to 11%.
Anything outside those targets could lead to clostridial growth (and secondary fermentation). That could result in lower intake, gastrointestinal upsets, low gains and lower milk production (but not necessarily botulism – although the symptoms can be similar). The pH needed to inhibit clostridial growth varies with the moisture content.
Leading “Baled Silage Research Needs Going Forward” was Dennis Hancock, Ph.D., dairy forage research center director at the USDA Agricultural Research Service in Madison, WI. This was more of a hypotheticals discussion in which he spoke about areas that need to be looked at and gathered input from those in attendance.
First, Hancock noted the anecdotal advantages of pre-cutting systems – but added, surprisingly, that almost no research has been done with baleage feed intake on animal performance. Hancock’s previous research looked only at animal preference and palatability of the feed.
“I think there’s a lot of work that needs to be done with animal performance,” he said.
When pondering whether pre-cutting “pays” or not, he added that not a lot of economic work has been done here either.
What about baling at higher moisture? How wet is too wet? It’s a careful line to toe, as in more northern latitudes, that baleage might be an ice cube when it comes time to feed. And with additional moisture, how stable would it be at feedout?
Hancock noted that forage species differences may change the management options. Some farmers are using cover crops and making them into dual-purpose plants, particularly rye and triticale. But are they effective?
“What we’ve found is if you’re doing baleage with bermudagrass, it’s never gonna pay for itself,” he said. “If you’re doing it with ryegrass or higher quality feed, it’s most likely gonna pay for itself.”
Another thing farmers need to look at is wheel traffic yield reductions. “With haymaking, that’s a huge factor that we don’t take into consideration,” he said. “Seventy percent of the plants in a field are driven over at each harvest and there are some plants that are driven over 10 times during a season.”
As for whether inoculant use makes sense, Hancock replied, “The theory with inoculants is that we’re shifting the balance of that lactic acid bacteria earlier on in the cycle, dropping that pH more quickly and getting a more rapid fermentation. I think there’s some merit to the benefits of that, and I think there may be even some real merit to those heterofermentative inoculants where we get a lot more acetic acid formed at the tail end of the fermentation period. Acetic acid helps us make this [baleage] more stable, less prone to mold and yeast development.”
Finally, when asked if there were any advances in reducing or reusing the plastic wrap used in storing baleage, Hancock answered honestly – not really.
“The best strategy I can see is that cattlemen’s associations could make a bin available for collection [at state meetings], but the economics of it right now are not in our favor,” he said. The silver lining is that there is a company in Wisconsin, and a few others, trying to work on that particular problem.
by Courtney Llewellyn
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