Silage Safety
Beware of mycotoxins even without visible mold.
In many cases, mycotoxins won’t alert livestock producers to their presence. There may be no visible mold and no bad smell.1 Yet, the infestation can be there — waiting to drag down production, decrease herd health, lower fertility and even be a food safety hazard.
“While mycotoxins are produced by specific molds, visible signs of mold may not translate to measurable mycotoxin levels and vice versa,” says Renato Schmidt, Technical Services — Silage, Lallemand Animal Nutrition. “It’s virtually impossible to completely avoid mycotoxin exposure. The toxins can be produced both on the growing crop and during storage and feedout.”
To help reduce mycotoxin production, producers can plant insect- and disease-resistant varieties, avoid leaving stubble standing in the field and practice crop rotation. It helps to avoid or minimize the effects of plant stressors like inadequate fertilization. Still, producers cannot avoid damage from pest infestation or weather events that can predispose crops to mold infestation and mycotoxin production.
When the crop has been stressed or physically damaged, the potential for mold infestation significantly increases. In these cases, Schmidt advises producers to take extra care with silage management.
To help minimize mycotoxin-producing molds — and all molds that cause spoilage — producers should use proven silage inoculants as part of a good overall management program. For example, silage inoculated with Lactobacillus buchneri NCIMB 40788 will be more resistant to heating and spoilage as this organism reduces the growth of yeasts, the initiators of spoilage. In fact, applied at 400,000 colony-forming units (CFU) per gram of silage, or 600,000 CFU per gram of high-moisture corn (HMC), it has been uniquely reviewed by the FDA and allowed to claim improved aerobic stability.
In the ensiling structure, molds tend to grow in hot spots where there is air (oxygen) present, Schmidt notes. This is typically in poorly sealed surface layers, corners or shoulders of ensiled forages, or where pockets of air were trapped and packing was inadequate.
“If visibly moldy silage is identified, discard it,” Schmidt advises. “Feeding even small amounts of spoiled silage into a ration has been shown to reduce dry-matter intake and NDF (nondigestible fiber) digestibility of the whole ration.2 While it may feel like an economic hit, you’re risking more in terms of lost production, herd health and reproduction if you choose to feed spoiled silage.”
For more information about mycotoxins and mold in silage, livestock producers can download a free copy of the Silage Quick Facts Handbook at qualitysilage.com/contact.
Editor’s Note: This article is from Lallemand Animal Nutrition.
1 Rankin M and Grau C. Agronomic Considerations for Molds and Mycotoxins in Corn Silage. University of Wisconsin-Extension. Focus on Forage,2002;(4)1. Accessed March 8, 2018. Available at https://fyi.uwex.edu/forage/agronomic-considerations-for-molds-and-mycotoxins-in-corn-silage/.
2 Whitlock LA, Wistuba T, Siefers MK, Pope RV, Brent BE, Bolsen KK. Effect of level of surface-spoiled silage on the nutritive value of corn silage-based rations. Cattlemen’s Day 2000. Accessed May 21, 2015. Available at: http://krex.k-state.edu/dspace/bitstream/handle/2097/4652/
cattle00pg22-24.pdf?sequence=1.