Arm & Hammer Animal and Food Production
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WEBINAR: Avoid events that trigger Clostridia outbreak.

Posted November 02, 2020 by Tom Rehberger, Ph.D., Director, Research and Product Development


Bacteria are everywhere on a dairy. Some bacteria are beneficial, even supportive to the production of large volumes of high-quality milk. Other bacteria are harmful, lying in wait to cause harm to people, animals and milk. 

One of those destructive bacteria is Clostridium perfringens. It’s a difficult pathogen to control, because it’s present in all areas of the dairy—in the soil, feed, manure, and in many other areas. They can lay dormant for a long time, creating spores that are resilient to a variety of adverse environments. Present inside the gastrointestinal tract of calves and cows, they become pathogenic once their host is compromised. 

An infection caused by C. perfringens can be devastating to the animal. Off-feed events are one symptom which can have a negative impact on the immune system. If the infection remains subclinical, the result can be reduced production, increased gastric disturbances and generally poor and variable performance. Clinical signs can include leaky gut or Hemorrhagic Bowel Syndrome (HBS). Severe cases can result in death. 

Growth inside the cow

The most common way for animals to get a clostridial infection is to consume contaminated feeds. Even if clostridial counts are low in the feed, the animal consumes a tremendous amount of feed throughout the day which can push bacterial loads to harmful levels. Once inside the animal, there are several factors that favor the development of clostridia infections in the intestinal tract:

  • Off-feed events that cause slug feeding. This could be due to weather when an animal could be off-feed during the period in the day when temperatures are the hottest, and then slug feed when temperatures are lower. This also happens in overcrowding situations when the less-aggressive cows slug feed when there is an opportunity to eat.
  • Bypass starch. Reduced starch utilization in the rumen could be a factor that leads to clostridial growth in the lower GI tract. This may be why some animals in the same pen, eating the same diet could have large variation in the levels of perfringens and total clostridia in their GI tract.
  • Excess of metabolizable protein. Some clostridia are scavengers of amino acids. If they can find additional sources of protein, particularly in the lower GI tract, it can provide the necessary building blocks for proteins necessary for rapid growth in the GI tract.
  • Stress. Any stressors, such as weather conditions, pen events, feed changes and so forth can increase health events associated with clostridial outgrowth. 

Assess and control

The first step to control clostridia and build herd resiliency is to conduct an assessment to determine the total clostridia and C. perfringens risk factors. Fecal, TMR and forage samples are collected and analyzed at the ARM & HAMMER lab in Wisconsin. The results indicate risk factors and identify available tools to help control outcomes, and producers can make management adjustments to help reduce the impact of clostridia on their herd.

Building a resilient herd can start with feeding CERTILLUS in the ration. CERTILLUS contains Bacillus, traditionally used to target toxigenic and non-toxigenic clostridia. Research1 shows that Bacillus strains found in CERTILLUS can increase the types of proteins used to tighten junctions between cells responsible for creating a barrier that prevents pathogenic bacteria, like C. perfringens, from entering the animal. 

The positive impact of feeding CERTILLUS includes more consistent feed intakes and fewer off feed events. This leads to a decrease in issues resulting from a compromised GI tract, and subsequently fewer cows in the sick pen. A healthier, more resilient herd translates to higher production, including more pounds of milk and associated components. 

While not all strains of clostridia are harmful, those that do cause harm can have a significant impact on cow health and productivity. It’s important to take not only the proper management steps to avoid clostridial contamination, but include the right feed ingredients in the ration to reduce the impact of clostridial outgrowth.



1 Lillejoj et. al., 2017. USDA Beltsville



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