Despite the conditions we may currently see when we look outside, spring is here! As temperatures begin to rise and snow begins to melt, we need to keep watch for changes in our stored forages. As many will remember, the corn silage harvest last fall brought with it plenty of challenges. Most dairies have not yet experienced any of the issues that are expected to arise in their silage piles thanks to those harvest challenges — but spring will change that. As temperatures increase, wild yeast will begin to awaken in silages, leading to a decrease in forage stability, as well as the potential for issues with the total mixed ration (TMR) fed to livestock.

Last fall, high yeast levels were found in the fresh corn silage samples collected for the Alltech Harvest Analysis – North America (HANA). I have not seen many stability issues for silages yet, but they will manifest. As the warmer weather awakens the wild yeast, we will start to notice activity in our silages that was not present during the long, cold winter. When wild yeast is active in silage piles, it begins to feed on the energy from the corn silage, decreasing the energy available to livestock. Wild yeast can create many issues for a dairy, from decreasing forage stability to causing rumen upset at feeding. Additionally, the silage will begin to warm, leading to an increased pH and spoilage on the silage face, top and sides of the pile or bunker. This is especially true when Mucor and Penicillium molds are present.

If these changes go unnoticed in the forage storage unit and the silage is fed, symptoms will begin to appear in the barn. Common symptoms of active wild yeast being fed in silage include inconsistent and loose manure, decreased dry matter intake (DMI), a downturn in the farm’s butterfat test and, of course, reduced milk production.

Wild yeast has a negative impact on rumen function and cow performance. When this happens, I am often asked, “What can we do about this?”

Common symptoms of active wild yeast in dairy:

• Loose, inconsistent manure
• Decreased butterfat
• Decreased milk production
• Decreased dry matter intake

TEST THE FEED

First, evaluate and address the issues and concerns at the silage face. Whether your corn silage is stored in a silo, a bag, a bunker or a drive-over pile doesn’t matter; if the environmental conditions allow for it, wild yeast and spoilage can occur in any storage unit. If you think wild yeast is present, my first suggestion is to test the feed through a local lab, as this will give you clear answers about the levels and the specific types of contamination you are facing.

MANAGE YOUR STORAGE UNIT PROPERLY

The next step is to evaluate the silage face, looking specifically for any visible signs of heating or spoilage. This can be done by the producer and nutritionist, but an Alltech on-farm representative can also help identify any potentially concerning signs by using a thermal imaging camera. If any heating or spoilage is detected, an improvement in face management will be necessary. This can be accomplished by increasing removal rates from the face and keeping the face smooth and clean by using a facer. I have personally seen many producers not using their facer daily in the winter months due to the extreme cold, and while this is understandable, when the weather warms and becomes more spring-like, using a facer will be critical to minimizing the effects of wild yeast and spoilage.

DISCARD SPOILED FEED

Next, do not be afraid to discard suspicious forage and spoiled feed. I understand that producers do not want to be wasteful by throwing away feed every day, but if poor-quality forage is fed to our livestock, their performance will be negatively impacted.

FEED A LIVE YEAST

Lastly, feeding a quality live yeast like YEA-SACC® can help livestock overcome the adverse effects of wild yeast. Yea-Sacc bolsters the rumen by modulating the pH, scavenging oxygen, eliminating stress brought on by the wild yeast strains and enhancing overall rumen function. These benefits keep livestock performance on track and allow the animal to utilize the forages efficiently.

I want to learn more about improving nutrition on my dairy.

The devastating flooding in the Midwest has led not only to human loss but has also destroyed infrastructure, homes and farm buildings — not to mention the additional financial loss due to flooded grain facilities. The images of ruptured grain bins and flooded grain show only a portion of the destruction caused by this disastrous event.

Grain that has been subjected to flood damage is considered contaminated for food and feed use. Grain that was stored in the same facility but did not come in contact with floodwaters can be utilized as normal, but precautions should be taken. Grain from the upper portion of the bin must be removed from the side or the top; due to potential contamination, it cannot be removed through the bottom of the bin. Make sure the electricity is disconnected, as there will be a greater risk of potential shorts and damaged electric motors. Once removed, grain can be handled in various ways, including flat storing and bins.

Flat-stored corn should be closely monitored for temperature and moisture, as moist grain can sometimes flare up in “hot spots” and warm temperatures. When the temperature inside the grain pile reaches 150° F, the grain begins to compost, so it should be mixed or stirred. If the temperature reaches 170° F, the grain may begin to smolder and has the potential to catch fire. Monitor pile temperatures with deep probes or by driving pointed pipes into the pile, followed by lowering in a thermometer. Since this grain could be subjected to rainfall, it is important to continue monitoring it until the grain can be moved or covered.

Grain that is moved to bins will also need to be monitored. Aim for the recommended grain moisture level of 14 percent moisture for storage. Some producers utilize standard natural air bin drying systems with perforated floors and high-capacity fans. Supplemental heat can also help speed up drying time, but take caution not to raise the air temperature more than 10°–15°F.

Along with moisture, grain must also be monitored for mold and mycotoxins. Molds may or may not be visible and, as such, the grain should be analyzed. Mold can produce mycotoxins that impair animal performance and health while also reducing the grain’s nutritional value by lowering its energy level. Propionic acid can help control and maintain mold levels in stored grains, but application rates will vary based on the grain’s moisture level and the percent of propionic acid used in the product.

If it has not been contaminated by floodwaters, grain from flood-damaged facilities can be salvaged and properly removed, monitored for health and moisture in a new storage facility, and analyzed for mold and mycotoxins.

The recent flooding speaks to a larger concern for grain producers in the Midwest, where some areas experienced the wettest 12 months (April 2018 to April 2019) in 127 years. Overall, corn planting in the United States is 6 percent behind the five-year average — but some Midwestern states are even further behind than that. Of the top 18 corn-producing states, five had not begun planting by April 21. Topsoil moisture is at a 29 percent surplus for the entire U.S., with subsoil at a 26 percent surplus. A wet, delayed spring planting can put crops in jeopardy of pollinating and maturing in a more challenging environment. These trials could also subject the plant to mold and mycotoxin infestation.

Visit knowmycotoxins.com for more information on mycotoxin risks and solutions, such as the Alltech 37+® mycotoxin analysis test.

Download a free poster!

Molds and mycotoxins can be detrimental to both crops and livestock feed. Toxin-producing molds may invade plant material in the field before harvest, during post-harvest handling and storage, and during processing into food and feed products. Prevention through sound management practices is essential, since there are limited ways to completely overcome problems once mycotoxins are present. 

1. Understanding contamination:

Plants are infected with mold and mycotoxins when spores of certain diseases are released and blown onto plants and soil. Spores can overwinter in the soil, leading to infection in the following years. 

2. Prevention:

Three steps can aid in the prevention of mycotoxin infestations. The first step should be to act before any infection has occurred. If that is not possible, you should act during the period of fungal invasion of the plant material and mycotoxin production. If, unfortunately, you should miss either of those opportunities, action should instead be initiated when the agricultural products have been identified as heavily contaminated. Most of your efforts should be concentrated on the two first steps because once mycotoxins are present, they are difficult to eliminate. 

• A list of recommendations for attempting to limit mycotoxin presence in corn has been released by the North Carolina State University College of Agriculture and Life Sciences. The suggested steps include:

  • Early planting

  • Reducing drought stress

  • Minimizing insect damage

  • Early harvest

  • Avoiding kernel damage during harvest

  • Drying and storing corn properly

  • Disposing of corn screenings instead of feeding them to animals

3. Seed hybrids:

If mycotoxins or diseases have been present in previous years, selecting seed hybrids that are resistant to them can reduce the risk and/or the severity of the infection. Some diseases can also be seed-borne, so it is important to be selective with the seed hybrids chosen for upcoming years.

4. Crop rotation and tillage:

Due to the cycle of fungi and spores wintering in the soil and on crop residues, increased tillage and crop rotation are recommended to help control crop residues and potential mycotoxin contamination. Removal, burning or burial of crop residues aids in the reduction of Fusarium inoculum, which could affect the subsequent crop. 

5. Planting date:

The date when seeds or seedlings are planted can also affect the contamination of your crop. Ideally, the flowering stage of the crop and spore release would not occur at the same time, in order to reduce the chances of infection. However, weather changes could challenge any advantages manifested by appropriately timing your planting.

6. Plant nutrition:

Well-nourished plants have more effective defenses. A proactive fertilizer program, accompanied by the best practices listed above, can help reduce the need for chemical pesticide intervention later in the season. 

7. Managing the problem:

Sound management practices in the field won’t eliminate the need for a mycotoxin management plan during storage or at the feed mill — they can help make an unmanageable problem manageable, but no approach is 100-percent effective, and new contamination can occur at multiple points, including during transport and storage. Consequently, mycotoxin risk should be evaluated and addressed throughout the feed chain. 

I want to learn more about recommended crop management practices.

Fumonisin is commonly found in corn at levels of 2 parts per million (ppm) or less, but in recent years, testing has confirmed levels well above 30 ppm, and some even above 100 ppm. Livestock producers should be aware of the fumonisin contamination when purchasing grain because, when consumed by animals, fumonisin toxicity affects several of their biological systems, leading to reduced feed intake and efficiency and liver damage. Understanding the effects of these mycotoxins in cattle feed is key to maintaining animal health and productivity.

Mycotoxins in contaminated feeds have differing effects on animals. 

Mycotoxins are secondary metabolites of molds and fungi that infect plants. More than 500 mycotoxins have been identified, and most animal feedstuffs are likely to be contaminated with multiple mycotoxins. The effects of mycotoxins vary, as each mycotoxin has its own specific impact on the animals consuming the contaminated feeds.

The Fusarium species are the predominant types of mold that contaminate crops and, eventually, animal feed. Ranging from white to pink or red in color, these molds are associated with wet conditions and moderate temperatures, especially following insect or hail damage. They are found worldwide, largely in corn. Fusarium molds produce several mycotoxins, including fumonisin, deoxynivalenol (vomitoxin) and zearalenone, with higher concentrations in the stalks and cobs than in the grain.

Signs of fumonisin in cattle

While cattle are generally resistant to many of the negative effects of mycotoxins, thanks to the degradation of the compounds by rumen microbes, high levels of mycotoxins in feeds can significantly impact animals. Fumonisin, in addition to not being significantly degraded in the rumen, is also not well-absorbed. The majority of fumonisins consumed by cattle are passed out in the feces. However, fumonisins can overwhelm the gut and cause significant issues in cattle.

The presence of fumonisin in the feed reduces palatability and, as a result, slows intake. Cattle may stand off a bunk contaminated with high levels of fumonisin. Calves without fully developed rumens and animals that are dealing with stressful situations, such as weaning or transportation, have an increased sensitivity to fumonisin due to reduced rumen fermentation and weakened immune functions.

Fumonisin can negatively impact animal health:

Even low levels of fumonisin affect gut health.

The gastrointestinal tract is impaired when cattle consume mycotoxins. Gut epithelial cells need protection from direct interaction with microbes and the gut environment. Specialized cells in the epithelium provide this protection. One example of these specialized cells is goblet cells, which produce mucus, coating the epithelial cells to lubricate and protect them from the contents of the gut. Intestinal cells also have specialized structures to form tight junctions, limiting the passage of molecules between cells. These mechanisms and others work in concert to prevent pathogen colonization and systemic access by toxins and pathogens.

Although fumonisin is poorly absorbed and metabolized by cattle, it induces disturbances in the gastrointestinal tract. Rumen motility can slow down, resulting in the increased exposure of the intestinal epithelium to the effects of fumonisin and other mycotoxins. Even low amounts of mycotoxins in cattle feed can impair intestinal health and immune function, resulting in altered host-pathogen interactions and an increased susceptibility to disease. The epithelial cells in the gastrointestinal tract are damaged by fumonisins, reducing the mucin layer thickness, tight junction strength and cell proliferation and, ultimately, increasing the opportunity for pathogen invasion.

Fumonisin has toxic effects on the liver and kidneys.

An analysis of tissues from cattle fed Fusarium in high doses indicated that the majority of fumonisin absorbed is retained in the liver, with lesser amounts retained in the muscles and kidneys. This accumulation is concerning, as fumonisin is toxic to the liver and kidneys and causes apoptosis, followed by the proliferation of regenerative cells in the affected tissues. Fumonisin also reduces the antioxidant levels in the liver, decreasing the animal’s defense mechanisms. This leads to liver lesions and elevated enzymes that are indicative of liver damage.

Fumonisins interrupt sphingolipid synthesis and metabolism.

The disruption of sphingolipid metabolism is the mechanism underlying much of fumonisin’s negative impact in the body. Sphingolipids are specific types of fats that protect cells from environmental damage by forming a stable, chemically resistant layer on the cell membrane. Fumonisins disrupt cell signaling by inhibiting ceramide synthase, interrupting sphingolipid synthesis and metabolism, and can alter the morphology of affected cells. This reduces cellular stability and protection, leading to cell death and significant alterations to cellular metabolism and cell-to-cell communication. 

Mycotoxins can increase susceptibility to diseases.

Calves that consume fumonisin experience decreased immune function, due in part to the impairment of lymphocyte development. Sphingolipid metabolism in immune cells is involved in the signaling pathways that control lymphocyte development, differentiation, activation and proliferation. Lymphocytes are the white blood cells that are important for maintaining a strong antigen response. These lymphocyte-related problems mean that consuming Fusarium molds can increase an animal’s susceptibility to diseases and reduce vaccine efficacy.

Handling contaminated feed in your beef cattle operation

Unfortunately, once mycotoxins are formed in the plant, there is no commercial method of removing them from contaminated feeds. Harvesting and storing contaminated crops at low moisture levels (i.e., less than 15%), along with the separation of highly contaminated feeds, is important in order to reduce the risk of mold growth and mycotoxin production in uncontaminated grain.

While the European Commission recommends that adult cattle can tolerate fumonisin levels of up to 50 ppm in diets, the U.S. Food and Drug Administration’s guidance for fumonisins recommends a maximum concentration of 30 ppm in the diet of feedlot cattle, 15 ppm for breeding stock and 10 ppm for calves. Furthermore, contaminated corn or corn byproducts should contribute no more than 50% of the diet. It is crucial to check the level of fumonisin in the complete diet, as it can be three times more concentrated in corn byproducts, such as distillers grains and corn gluten feed, and 10 times more concentrated in corn screenings.

If contaminated feeds must be used to feed cattle, elevators may blend the corn to reduce the fumonisin concentration to acceptable levels, or producers can include feed additives to mitigate the risk of mycotoxins. As fumonisin is associated with reduced feed consumption, there is a concern that low levels of fumonisin can interact with other mycotoxins, reducing the growth of calves and slowing the weight gain of feedlot cattle. Fumonisin contamination can be especially detrimental to newly received cattle and calves, preventing them from getting off to a healthy start.

Testing services like Alltech® 37+ and Alltech® RAPIREAD® can help producers and feed mills assess their mycotoxin risk so that the appropriate management and nutritional measures can be put in place.

I want to learn more about nutrition for my beef cattle.

[DUNBOYNE, Ireland] – The Alltech 37+® mycotoxin analytical services laboratory in Dunboyne, County Meath, Ireland, was accredited in accordance with the international standard ISO/IEC 17025:2005 from Perry Johnson Laboratory Accreditation, Inc. This objective, third-party assessment distinguishes the managerial and technical requirements of the lab and ensures the accuracy and impartiality of analytical results.

The European Alltech 37+ mycotoxin laboratory, which opened in April 2016, is the third of its kind for Alltech, which has two similar laboratories in the U.S. and China. The proprietary 37+ LC/MS/MS analytical method, developed by Alltech, is included in the scope of accreditation. This analytical method is state-of-the-art in its detection and quantisation of more than 37 mycotoxins at parts per billion (ppb) and parts per trillion (ppt) levels.

“This accreditation sets the bar in global mycotoxin investigation and reaffirms our customers’ confidence in the precise, accurate and thorough testing of the Alltech 37+ mycotoxin analysis programme,” said Steve Mobley, manager of the European Alltech 37+ mycotoxin laboratory.

“Our diagnostic approach allows us to further investigate livestock and poultry health issues, study global mycotoxin trends and develop comprehensive, customised mycotoxin management programmes for our customers,” continued Mobley.

Led by Dr. Emma Daniels, senior analytical chemist and laboratory coordinator, the Alltech European 37+ laboratory provides much-needed, high-throughput mycotoxin profiling services to accelerate the detection process while saving time and money for European farmers and food producers.

Run in conjunction with the Alltech® Mycotoxin Management programme, Alltech continues to collate a powerful database, which recognises mycotoxin issues throughout the world. To date, Alltech’s mycotoxin laboratories have analysed more than 14,000 samples since opening its first dedicated facility in Lexington, Kentucky, USA, in 2012.

Research carried out on mycotoxin samples analysed in January and February in North American silages showed evidence of type B trichothecenes and fusaric acid. Although type B trichothecenes are still a prevalent mycotoxin group found in silages that can damage the health and productivity of animals, recently, there has been increase in the number of cases of type A trichothecenes and other Penicillium mycotoxins. In Europe, type B trichothecenes are still common among silages, but there is also a high risk from the other Penicillium mycotoxins, which occurred in 45 percent of samples at an average of 1,533 ppb.

For further information on the Alltech Mycotoxin Management programme, please visit www.knowmycotoxins.com.