Manage Molds And Mycotoxins For Optimal Rumen Function

Mycotoxins can be the source of several important herd health problems ranging from reduced feed intake to suppressed immune response. With consequences like these, it pays for producers to manage — and prevent — mycotoxins before contaminated feed hits the bunk.

Yet prevention isn’t always possible and ensuring rumen function is maximized can help head off herd health problems, notes Anthony Hall, MSc MSB, PAS, Technical Services, Ruminant, with Lallemand Animal Nutrition.

“Mycotoxins are produced by specific molds, which are impossible to entirely avoid in the process of growing and storing crops for cattle feed,” Hall says. “Ruminants are actually more resistant to the effects of mycotoxins than monogastric animals like pigs and poultry. However, the toxins can disrupt rumen function in important ways.”

Researchers have found that mycotoxins can cause lactic acid to build up, which can result in Sub Acute Ruminal Acidosis (SARA). SARA is a sustained period of time with lowered pH levels in the rumen. When SARA occurs, the animal’s ability to use the ration efficiently is impaired and can lead to other, more serious, health problems like laminitis. This research may explain why acidosis and laminitis are also commonly observed when mycotoxins are a problem.1

“SARA is simply an occupational hazard for the modern dairy cow, and mycotoxins are just one of the reasons it can occur,” Hall says. “The costs from SARA are estimated at $1.12 per cow daily,2,3 which can quickly add up.”

Mycotoxins can accumulate on plants in the field, during harvest, storage or feedout of silage. To reduce exposure, the first step is to reduce or eliminate mold growth in silage production. Mold growth can occur in hot spots where there is air present. This is typically in poorly sealed surface layers of ensiled forages.

“Proper silage management is key to reducing the presence of all kinds of molds, including those that produce mycotoxins,” Hall notes. “Plus, there are great benefits to good silage management beyond preventing mycotoxin production, including improved dry matter recovery and better quality feedstuffs.”

Hall recommends producers discard any visibly mold silage and to help minimize spoilage place, he recommends using proven silage inoculants. For example, silage inoculated with Lactobacillus buchneri 40788 will be more resistant to heating and spoilage as this organism reduces yeast levels, which improves feed stability. L. buchneri 40788 applied at 400,000 CFU per gram of silage or 600,000 CFU per gram of high-moisture corn (HMC), has been uniquely reviewed by the FDA and allowed to claim improved aerobic stability.

If contaminated feed manages to reach the feed bunk, it’s important animals’ rumen function is maximized. Producers can include a research-proven active dry yeast (ADY) probiotic in the ration to help achieve this goal.

“ADY probiotics that include the strain Saccharomyces cerevisiae CNCM I-1077 have a high capacity to increase pH and fiber digestibility in the rumen,” Hall notes. “Probiotic feed additives can help improve rumen function and increase fiber digestion. This can help avoid reduced production due to a number of herd health challenges, including mycotoxins.”