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Jump-start calf rumen development with viable microbial products

Andy Skidmore for Progressive Dairy Published on 06 May 2020

From birth, calves’ naïve immune systems are assaulted by challenges: new environments, fast diet transitions, exposure to disease and sometimes transportation and commingling. That makes it no surprise the dairy industry continues to battle pre-weaning losses.

The Dairy Calf and Heifer Association (DCHA) Gold Standard for early survival rates is greater than 97% 24 hours to 60 days after birth. Yet the average mortality rate for pre-weaned calves is about 7.8% in U.S. dairies. That means nearly all operations can make improvements in this area. Some industry experts believe morbidity and mortality rates for pre-weaning dairy heifers are still alarmingly high even though U.S. producers decreased losses by 6% from 2007 to 2014.



Why are these mortality rates so high? Of course, any dairy producer will tell you a major calf disease threat is scours. At birth, the gut of a calf is just beginning to develop. During the past few decades, our knowledge of intestinal health has grown. There is conclusive evidence that microbes within the gastrointestinal (GI) system communicate and influence many aspects of an animal’s performance and well-being.

Microbes communicate with the brain and central nervous system. In fact, we now understand the lower gut is the primary immune organ of the calf. Many calfhood illnesses start in the gut and can be prevented with good gut health and proper management.

The next frontier in calf health

Now that we know what the gut is capable of, we can begin to positively influence it. One of the most effective ways to do this is through the use of probiotics. A probiotic is defined as a live micro-organism, which – when fed in adequate amounts – confers a health benefit on the host.

Certain probiotics have been proven to stimulate microbial communities, enhance gut health and support the immune system. In a recent study published in the Journal of Dairy Science, researchers found that Saccharomyces cerevisiae boulardii CNCM I-1079 fed to calves at a rate of 10 × 109 colony-forming units (CFU) per day resulted in calves experiencing less incidence of scours and requiring fewer antibiotic treatments (Figure 1).

Calf diarrhea over time


Plus, the study’s authors noted the calves fed S. c. boulardii maintained their growth performance while experiencing severe diarrhea.

S. c. boulardii works in the animal’s lower gut to positively influence the calf’s natural immunity through an active process. It causes beneficial microbes to flourish in the lower GI tract and help inhibit pathogenic bacteria. This action has been proven in multiple species including cattle.

Preparing the rumen for forage

Proper rumen development sets the stage for future growth and lactation performance. During the first months of its life, the calf’s digestive tract undergoes significant changes as it evolves from its initial monogastric function to a fully functioning ruminant. Poor management during this pre- through post-weaning period will result in reduced rumen development, lowered feed intake and growth with increased diarrhea and morbidity.

This can lead to long-term consequences. Performance as an adult lactating cow can be lost, and studies have shown a clear link between post-birth live-weight gains and future performance into the third lactation.

By weaning, calves need to have a suitably developed rumen to be able to digest forage-based diets. Peer-reviewed research has documented improvements in performance and rumen health in cattle fed active dry yeast (ADY) probiotic. The specific strain Saccharomyces cerevisiae CNCM I-1077 has shown increases in weaning weight and feed intake in calves.

One study in New Zealand showed calves supplemented with S. cerevisiae CNCM I-1077 in their starter feed had steady feed intake and weight gain during the weaning phase, leading to improved bodyweight (Table 1).


Feed intake for weaned calves

The researchers attributed this to better rumen functionality at this important time of development.

Specific strains needed for success

Not all probiotics provide this response and not to the same level. Specific strains of probiotics are needed to influence the calf’s natural immunity through an active process. This process works by favoring beneficial microbes in the GI tract.

Specific strains of probiotics are much more efficient and perform to a greater level at delivering these effects, particularly in pre-weaned calves. Producers should look for specific strains that achieve the desired result and are proven to produce that result in dairy calves. It’s similar to choosing a breed of cattle. All cattle give milk and make steaks – it’s just that some breeds do one or the other more efficiently than others. All cows are not the same. The strain of a specific probiotic is as important as the breed of cow is to the desired outcome. They are all very different. You wouldn’t use the same strain of yeast to make a donut as you would to improve calf health.

In addition, the efficacy of probiotics is directly linked to manufacturing and quality-assured production processes. These are live, active microbes and must be carefully handled to ensure the desired results. The formulation of the probiotic is also important. Well-formulated probiotic yeasts can be added to milk replacer, raw or waste milk for easy delivery to neonatal calves or micro-encapsulated to be incorporated in growing rations.

Management remains a priority

Probiotics can help support the immune and digestive systems, but they must be combined with other good nutrition and management practices that help reduce stress and promote growth. To further improve calf health and performance, it is important that producers continue to implement good management practices to reduce or eliminate the main causes of stress, such as:

  • Abrupt feed changes
  • Poor ventilation
  • Overcrowding
  • Exposure to sudden weather changes
  • Excessive heat or cold

In addition, carefully transport, vaccinate and handle pre-weaned calves to reduce the stress associated with these events.

Calves are less likely to experience scours when the natural balance of microbes in a calf’s digestive system are in balance. In addition, the digestive system is where feed provides the nutrients that power all other functions. An efficient, balanced digestive system can have positive systemic effects on the immune system, which can help the animal stay healthy, get the most out of their feed and attain its genetic potential.  end mark

Andy Skidmore received his DVM from Kansas State University and his Ph.D. in animal sciences from Cornell University and is employed by Lallemand Animal Nutrition, North America as a technical services – ruminant team member.

References omitted but are available upon request. Click here to email an editor.

Andy Skidmore
  • Andy Skidmore

  • Technical Services – Ruminant
  • Lallemand Animal Nutrition, North America