Live Probiotics – A Growing Trend in Calf Diets

Published on: 14:21PM Dec 02, 2013

The use of probiotics is not new to the dairy industry; however, feeding live probiotics to dairy heifers is a relatively new concept that is beginning to receive attention.

By Dr. Charles A.Jamison, veterinarian and technical services manager with Nutrition Physiology Company

According to USDA’s National Animal Health Monitoring System’s Dairy 2007 study, 20 percent of dairy and heifer operations used probiotics for preventative purposes, an increase from the 14.4 percent in 2002.

What are living probiotics and how do they work?

To many producers, probiotics remain a foreign concept because of a lack of information on what they are and what they do.

Simply put, probiotics are feed additives. They contain microbial species that are considered to be non-pathogenic (not harmful) normal gut flora. A probiotic is defined as "a live microbial feed supplement which beneficially affects the host by improving its intestinal microbial balance."1 Probiotics are also commonly referred to as direct-fed microbials.

Living probiotics typically consist of a combination of bacteria for both the rumen and the gastrointestinal tract of dairy cows and calves. The most common bacteria found in modern living probiotic products are lactobacilli.

A live probiotic’s mode of action is multi-modal in which one interaction may involve interfering with the attachment of E. coli and other gram negative bacteria to the lining of the intestinal tract. If bacteria can’t attach to the lining, it will be difficult for them to cause serious health issues for the animal. An animals’ immune system is also positively influenced by a healthier, more resilient digestive system micro-biome that can provide more energy for the animal’s immune system to utilize and also interact positively with the mucosal membrane/GALT (gut associated lymphoid tissue).

Living probiotics support calf health

Living probiotics have received acceptance in dairy heifer operations because of their proven abilities to improve calf and heifer health during times of stress and to incrementally increase the efficiency of feed conversion. Most research data suggests that improvement in animal performance from the inclusion of a live probiotic in the feeding regimen is due to a more balanced intestinal environment (micro-biome and development) and greater energy availability.

Research has also shown improved development of intestinal villi at weaning and improved development of the rumen papillae post-weaning.

Two of the most stressful times in a dairy animal’s life occur in the first couple months of life. The immediate days following birth and the weaning period are two critical periods that have been shown to benefit from the use of live probiotics. Stress can alter the gut’s micro flora population. Stressed calves with diarrhea have a lower population of lactobacilli in their intestinal tract and supplementing calves with specific lactobacillus acidophilus have shown to improve fecal scores with less incidence of diarrhea.

Opportunities to impact the development of the naïve digestive system of a young animal by creating a healthier gastrointestinal micro-biome that maximizes the energy capture from a diet can have a tremendous influence on the overall health and development of a calf.

Stress induced from weaning, transportation, changes in weather or medical treatment can negatively affect the normal micro-flora in the intestine. This recurring intestinal imbalance can make calves and heifers more susceptible to disease. The establishment of a normal bacterial profile can aid in maintaining optimal animal performance. The introduction of live probiotic bacteria has been shown to improve performance in young calves because of decreased scouring and improved growth rates.

Research has found that feeding calves a live probiotic resulted in greater body-weight gain and feed efficiency, not only during the milk feeding period, but also post-weaning. Improved average daily gain in post-weaned calves can be attributed to this improved intestinal development and a more stable digestive system micro-biome.

Considerations for use

Strain Selection

  • Living probiotics are currently being marketed with a combination of several bacteria, which makes it difficult to determine which organism contributes to an improved response. All strains are not the same and do not function in the animal’s digestive system equally. Take time to identify products that have a solid research program to support claimed benefits.


  • Live probiotics are living organisms, therefore the way in which they are manufactured, shipped, stored and handled is very important.
  • Conditions that can kill a living probiotic include but are not limited to storage for long periods, high temperatures, low temperatures, direct sun, high humidity and oxygen, and presence of mineral premixes.
  • Always follow manufacturer’s recommendations for storing and using all living probiotics.


  • Chlorination, temperature and mineral content all can affect viability of living probiotics.

Mixing with Milk Replacer and Waste Milk

  • Always follow manufacturer’s recommendations on use with milk replacer.
  • High water temperatures may kill the living probiotics.
  • Antimicrobials in milk replacer or waste milk may interfere with the viability of probiotics.
  • When using pasteurized waste milk, live probiotics should be added only after the milk has cooled to feeding temperature.

As continued research is released, demonstrating the benefits that feeding a live probiotic to dairy calves, it is important to realize that not all probiotics are equal. Make sure that the product you choose is backed by solid research trials for quality assurance. Take note of the strains of bacteria that are used in addition to the guarantee that the product is actually living.

It is important to read product labels and consult with a specialized product representative to ensure that you are following best practices to ensure that living probiotics are maximizing the potential of your heifers and grower calves. Live probiotics are a great technology to consider in any well-managed heifer rearing operation.