What are the most important animals on your dairy: lactating cows, dry cows, heifers or calves? The correct answer is: All of them. While lactating cows are your current source of income, calves and heifers are your future source of income.
Proper investments of time and effort to calf raising will definitely pay off in the long run. We all know that good calves make good cows, but the opposite is also true. Poor health during early life of calves is associated with reduced milk production when those calves become fresh heifers.
Producing and maintaining healthy calves will ensure quality replacement heifers for the next generation.
What is a probiotic?
The Food and Agriculture Organization and World Health Organization define probiotics as “live micro-organisms that, when administered in adequate amounts, confer a health benefit on the host.” For bacteria to be classified as probiotic, they must not only be alive when consumed by the host but remain alive inside the gut of the host.
Probiotics have a wide variety of modes of action and can therefore confer a wide range of benefits to their host. These benefits can include, but are not limited to: reduction in harmful pathogenic bacteria, improved feed utilization, development of healthier gut tissue and enhanced immune responsiveness.
Do your calves need probiotics?
Just as a ration is often supplemented with vitamins and minerals to supply a cow with a consistent source of required micronutrients, probiotics can be fed daily to calves to ensure a consistent population of healthy gut microbes. Maintaining a healthy population of gut microbes improves the likelihood of producing healthy, thriving, feed-efficient animals.
Calves are constantly faced with stressful situations, and we cannot predict the extent to which those stressors will negatively impact them. Sick calves cost money; some you pay up front for treatment, the rest you pay in poor lifetime performance. Having probiotics in your calf’s diet will help it get through stressful times faster, with less effort, and reduces the risk of lingering effects.
Improving your herd with probiotics
Calves are born with innate immune systems that are not fully formed. This makes them highly susceptible to infections during their first few months of life, and there are many types of pathogenic bacteria (e.g., E. coli, salmonella, clostridia) that will make calves sick. Severe infections can even lead to death.
Daily feeding of effective probiotics can help reduce the prevalence of pathogens within the herd as well as their concentration within individual animals.
Probiotics are especially effective against pathogenic bacteria because they do everything they can to enrich the environment for themselves while creating a hostile environment for their pathogenic competitors.
Fed daily, probiotic bacteria will compete with pathogens for space and resources in the gastrointestinal tract. Probiotics will produce bacteriocins, which are biologically active proteins with antibiotic-like activity. Bacteriocins kill pathogens directly. Probiotics will convert feed to acids, changing the intestine pH to make the environment undesirable for pathogens.
By reducing the pathogen load within the calf, it will also reduce the pathogen load being re-introduced into the environment through the feces. This reduction of pathogens within calves and in their environment leads to a healthier herd, where fewer animals will need to be handled or treated. Healthy calves will be able to put energy from feed into growth, while sick calves will have to divert some of that energy toward their immune systems.
Coping with stress
Calves experience many changes in the beginning of their lives that induce stress, which can negatively affect performance. Everything from weather changes, pathogen exposure, animal handling, diet changes and pen moves can cause stress on young calves. We are learning that the energy required to support an immune response can have significant impacts on animal performance.
Research from Penn State demonstrates the long-term effect of illness. In this study, for each day a pre-weaned calf was clinically ill, there will be an associated loss of 277 pounds of milk in its first lactation.
Probiotics work within their host animal to promote health. Probiotics are capable of signaling immune cells to help mediate an immune response. Feeding probiotics was shown to improve the immune response of cattle challenged with pathogenic bacteria.
Probiotics also work inside the gut to help protect the gut tissue and maintain the barrier function of the intestines, thereby preventing the absorption of harmful toxins or pathogens.
Promoting gut development
Calves are born with undeveloped rumens incapable of utilizing starch and fiber as nutrient sources. Therefore, it is important to set calves on a path to develop their rumen into a functional fermentation chamber early in life.
The rumen of a newborn calf is small, with smooth walls, and has little to no microbial population. As the rumen develops, we see an increased capacity and a simultaneous increase in absorptive surface area as the rumen wall develops small finger-like projections called papillae.
Nutrient byproducts of fermentation, such as volatile fatty acids, are absorbed through the rumen wall – so the greater the surface area, the greater the absorption of nutrients.
As calves begin to eat solid feed and are in contact with pathogens in their environment, there is an increase in the number and variation of rumen micro-organisms.
The physical development of the rumen and the establishment of a large, diverse microbial population must occur simultaneously in order to achieve optimal rumen function.
Probiotic bacteria can help stimulate the development of the rumen in wet calves, improving the efficiency of digestion of starter rations. Likewise, effective probiotics can improve the stability and function of the lower gastrointestinal tract.
Tissue samples taken from the ileum of calves fed probiotics are more pliable with a greater surface area, allowing for improved nutrient absorption.
A healthy microbial population is responsible for helping the calf break down plant-based feeds. This converts feed into energy to put toward growth, pregnancy and milk production later in life. In the adult cow, constant inoculation of novel bacteria is required to shift the microbial population and fermentation profile.
On the other hand, recent research suggests that in calves, early influence on the microbial population of the developing rumen may last into adulthood. By introducing key beneficial bacteria during early microbial programming, we may be able to set calves up for a lifetime of improved rumen function.
Selecting the right probiotic
So you’ve decided you want to add probiotics to your calf program, but how do you decide which one? The key is to know that “strain matters.” Strains of bacteria are like breeds of cows. Holstein and Jersey cows are the same genus and species (Bos taurus), but there are obvious breed differences in physical appearance and performance.
Likewise, there are many probiotic strains available that may be the same genus and species (e.g., Lactobacillus acidophilus), but the difference in performance can be profound. Each company will have its own combination of strains, each with its alleged benefits.
It is most important to solicit the help of your nutritionist or veterinarian to find the research conducted on the specific products you may be interested in feeding to your animals. Choosing a science-based, research-proven product is in your best interest.
Jill Havlin, Ph.D., P.A.S., is a technical services manager – Pacific Northwest, Chr. Hansen. Havlin provides dairy nutrition technical support to the sales team, customers and consultants, including insight on cow comfort, cow movement, bunk management and feed management. Havlin has her doctorate in animal biology from the University of California – Davis.
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