Together they help digestion…a LOT
By Gilda V. Bryant
When added to beef cattle diets, prebiotics and probiotics may help maintain health, improve digestion and advance overall performance. These products enhance microbial balance in the intestine and rumen. Interest in these products has ramped up, especially with the implementation of the 2017 Veterinary Feed Directive (VFD).
Probiotics, also known as direct-fed microbials, are a live microbial feed supplement, which improve the intestinal microbial balance. Prebiotics are non-living cells that nourish beneficial microbes in the rumen. To understand prebiotics and probiotics, it is helpful to review the ruminant digestive system.
Ruminant animals have one stomach with four compartments, resulting in efficient forage digestion. The rumen is the first and largest section of the stomach, and works like a fermentation chamber. It contains up to 50 gallons of plant fibers, liquids and billions of bacteria, protozoans and fungi. The rumen constantly churns the contents, breaking plant fibers into smaller bits for the rumen’s “bug” population to digest. The fibers ferment and encourage cudding, which further breaks down fiber and increases saliva production. Saliva keeps the rumen pH at the proper level, maintaining a healthy microbial environment.
Without a robust, active microbe population, the rumen cannot work properly. If feedstuffs do not contain the right balance of ingredients, such as fiber, energy, nitrogen and water, the microbe species can become imbalanced. This may result in acidosis or large populations of E. coli, for example.
Kevin Glaubius, Ph.D., Director of Nutrition and Regulatory Support, for BioZyme, Inc., says probiotics are living microorganisms that work synergistically with other microbiota (Cowboy Dictionary alert! – this word means ‘an ecological community of microorganisms that work together in the rumen and small intestine’). They reduce E. coli by either directly competing with the organism or by introducing an organism that changes the optimal pH E. coli prefers, reducing its growth rate.
“Prebiotics, on the other hand, are not live organisms,” Glaubius explains. “They provide support to the microbiota, allowing them to bounce back and recover faster after a stress [event]. Many of the disease organisms like Salmonella, E. coli, and Clostridium are opportunistic, meaning they flourish during stress when conditions are right. By using a prebiotic to increase the growth rates of the microbiota and supporting a stable and diverse microbiota in the digestive system, this allows animals to more quickly adapt to stress, leading to improved performance.”
Larger feedyards have the ability to mix feed and probiotics daily and these products are commonly added in the starting and transition diets, which challenge the rumen environment. Probiotics are added through a micro-system or injected in liquid form into the complete diet.
Additionally, feeding a prebiotic allows microbes to remain more stable, able to rebound more quickly in hot weather. Then they can maintain efficient digestion and minimize digestive upsets, preventing bad bacteria to dominate and cause immune challenges. Prebiotics lead to a more stable rumen pH, minimizing the negative impact of heat stress, for example.
Seventy percent of the calf’s innate immunity is located in the digestive system. Glaubius says the compromised immune system is a direct result of digestive upsets or less than ideal diversity within the microbial populations. Prebiotics mixed with minerals improve barrier function, which helps prevent bad bacteria from attaching to the lining of the small intestine. Prebiotic research indicates there is also less inflammation and improved nutrient absorption, combined with fewer “leaky” gut symptoms.
The VFD has led to a greater interest in research and development of natural prebiotics and probiotics. Glaubius is convinced current probiotic research will result in products that work even better in the future.
Keeping pathogens out
Jeff Young, Territory Sales Manager with Life Products, Inc., says live bacterial products can have significant interaction and impact on animals. For instance, probiotics can be used to help calves develop and maintain a stronger gastrointestinal tract (GIT) microbiome, a better epithelial barrier in the digestive system and help balance the immune system in the GIT.
“Probiotics can help create a more resilient and efficient digestive system, making it harder for pathogens to penetrate the intestinal barrier, maximize nutrient absorption and balance pro and anti-inflammatory responses,” Young reports. “This can allow the animal to maximize its genetic potential for the producer’s business.”
While probiotics are more commonly used in feedyard settings, cow-calf operators can give them to young calves with boluses or pastes at birth, blended into a creep feed or included in a mineral supplement. Young says it is important to assess the viability of the product when adding to feeds and minerals because only a live product is beneficial to animals.
Currently used prebiotics and probiotics work in different ways, including:
Specific prebiotics made from yeast tend to attach to and bind E. coli, Staphylococcus aureus and Salmonella, and are able to exit the animal before causing illness.
Some yeast species may reduce the physiological load during beta-agonist feeding periods during hot weather.
Certain plant-based prebiotics may improve mineral absorption in cattle.
Although producers are willing to look at these products, Young reports skepticism has grown since the market has been flooded with probiotics with little or no research or quality manufacturing to support them.
In the “figuring out” stage
John Richeson, Ph.D., who conducts feedlot trials at West Texas A&M University, says the recent VFD was a major signal for the cattle industry to consider antibiotic alternatives. It has been a struggle to find a probiotic that is a direct replacement for some of the feedyard antibiotics previously used to promote feed efficiency and increased performance.
“There are yeast and bacterial probiotic products available and many different species within those,” Richeson explains. “There are different times of application, duration of application and concentration to consider. I think the industry is still trying to figure out which probiotic strategies are the most efficacious.”
What are the appropriate concentrations and feeding durations? “Obviously, there are key times during the beef production process where physiological stress, nutritional stress and pathogen pressure is greater,” Richeson explains. “A lot of the research has been aimed at evaluating probiotic supplementation during those key times, but then some companies recommend providing their probiotic throughout the entire feeding period. We don’t exactly know yet what the best probiotic strains might be, the appropriate timing and duration of feeding and concentration. Research is still needed to refine probiotic supplementation.”
In Richeson’s extensive feedyard experience, it has been challenging to clearly show probiotic effectiveness in the commercial feedyard setting. He has had good responses in some cases and no responses in others. It is possible to feed a probiotic at a greater concentration or for too long a period, resulting in undesirable enteric inflammation in some cases.
How can feedyard managers get optimum benefits from probiotics? “Just as they normally would with any product, ask to see what research has been done because there are a lot of different products available,” Richeson advises. “Not all probiotics are created equal. There can be big differences of efficacy between two different products. The only way to differentiate that is to evaluate [the research].”
One area where probiotics often display positive results is when they are provided to commercially fed cattle during heat stress and/or beta-agonist feeding periods. Richeson encourages feedyard managers to plan for heat stress during hot summer months and beta-agonist feeding periods by providing a probiotic in preparation for those events.
“I think the industry is really pulling for probiotics to work,” Richeson explains. “We need to continue to research and fine-tune the feeding regimen with probiotics and discover which strains are the most efficacious. There could be different areas of application, where one strain works well for newly received cattle and another strain for mitigating the impacts of heat stress. We are definitely pulling for them to work, because we need non-antimicrobial tools in our toolbox to reduce antimicrobial use in the industry.”
From Yawner to “The BIG GAME”
Imagine, if you will, Dear reader…we are at ‘the game’. Actually, this event is happening in the rumen of a stressed feeder animal or young calf, so humor me here.
Everything in a typical ‘game’ harmonizes together to make it all work; the players, hot dog vendors, marching bands, ticket booth attendants, parking lot crew, EMT’s, security, referees, announcers, military, media and the fans. This analogy I have so generously concocted represents all the diverse microbiota and elements that make up the warm, moist and very active rumen environment that keeps the stressed feeder critter or young calf on its feet.
Now…let’s take this functioning but stressed rumen and make it even better.
Probiotics are itty-bitty living critters that are like a team of all-star athletes that run out onto the field (introduced in the feed) and take control. If the conditions are right they can transform a mediocre game (the stressed but functioning rumen) and supercharge it into a top-draw event where the scoreboard goes wild. A regular season yawner now becomes the BIG GAME!
Prebiotics are not live critters. They are non-digestable sugars, and they act like Security Guards at the BIG GAME. They attract nasty organisms like E. Coli and Salmonella, and they arrest them, toss them into the back of the Paddy Wagon and shuttle them off the property before they can run onto the field and attack the All-Star Probiotic Team.
See how that works now? Probiotics up the game, Prebiotics protect the game from unwanted attendees, and the crowd goes wild (because the calf performs better).