DFMs help balance microflora

Since man first brewed beer, baked leaven bread or made yogurt, naturally-occuring microorganisms have been used to process our food. Health benefits of beneficial bacteria were suggested as far back as the early 1900s. Today, the health benefits of probiotics for humans are well known and growing in popularity and consumption. What are called probiotics for humans are called direct-fed microbials (DFM) for livestock. And likewise the health and performance benefits of beneficial DFM is growing.

The concept of DFMs began in the 1950s when researchers observed a positive growth response in animals fed antibiotics. This led scientist to theorize that the intestinal microflora plays a role in the growth and development of an animal. Research determined that a healthy animal’s intestinal microflora consist of a delicate balance of two general types of microorganisms, beneficial and potentially pathogenic.

The coexistence of beneficial and potentially pathogenic bacteria is an important factor in the general health of the animal. If this balance is upset, the number of beneficial bacteria decline while the number of potentially pathogenic bacteria increase, comprising the animal’s health and growth. Feeding a DFM containing live, beneficial bacteria helps to maintain this balance, which assists in optimal animal health and performance.

DFMs in Animals

All animals have a complex collection of approximately 100 trillion microorganisms in their digestive tract, which has a major impact on animal metabolism, physiology and nutrition. Some of these microbes are beneficial to protecting the animal from disease and contributing to improved growth particularly where healthy gut balance exists.

By way of example a newborn animal quickly acquires beneficial bacteria from its mother and surrounding environment, and establishes natural resistance to enteric diseases caused by Escherichia coli and other pathogens. Studies of newborn animals show that as numbers of Lactobacillus and Enterococcus in the gut increase, E. coli numbers decrease. Therefore, it is desirable to establish early colonization of the gut with beneficial bacteria, however research has proven that animals can benefit from DFM at every life stage.

In fact, antibiotic therapy, ration change, weaning or other stress can upset intestinal microflora balance, causing a decrease in the number of beneficial microorganisms and an increase in pathogens, resulting in lower animal performance. There is good evidence that certain gut microorganisms are beneficial to the animal on a routine basis. The development of DFMs is based on this concept of influencing the intestinal microflora so as to improve animal health and performance.

Modes of Action

A number of modes of action have been identified for DFMs. There’s most likely a combination of these modes that contributes to the balancing of the animal’s intestinal microflora and subsequent

improvements in performance. However, the FDA restricts manufacturers from making performance or health claims in their promotional materials.

Production of Organic Acids

DFM bacteria produce a variety of organic acids that are reported to inhibit E. coli and other intestinal pathogens. The most common are lactic, acetic and formic acids, which lower intestinal pH and this, in part, may suppress harmful organisms. Acetic acid also lowers the O/R (oxidation-reduction) potential. If the O/R potential is reduced, organisms that require oxygen for growth, such as Salmonella and Shigella, will be inhibited. Organic acids also can serve as energy sources to the animal or other beneficial bacteria.

Production of Antimicrobials

Many researchers have reported that certain strains of lactic acid bacteria produce bacteriocins, antibiotics and other compounds that inhibit intestinal pathogens. These antimicrobial substances include acidilin, acidophilin, lactolin, nisin and hydrogen peroxide.

Deconjugation of Bile Salts

Bile assist fat digestion, and conjugated and deconjugated (free) forms of the compound inhibit growth of enteric pathogens. Certain Lactobacillus strains can deconjugate bile salts, which are the more inhibitory form.

Stimulation of Immune Response

Researchers have reported that when animals are fed lactic acid bacteria, the activity of their immune systems increases. These beneficial bacteria may stimulate antibody production and phagocytic activity against pathogens in the intestine and other body tissues. These animals are better prepared to resist a bacterial infection, and therefore less susceptible to disease.

Enzyme Activity

Beneficial bacteria, especially Bacillus, produce a variety of enzymes, which may help to explain increased feed utilization seen in normally healthy animals fed DFMs. Proteases, amylases, glycosidases, ureases and other enzymes produced by DFM bacteria break down complex feed molecules into simpler nutrients. These smaller components are more readily absorbed by the animal, or are used by other intestinal bacteria for growth and maintenance of a proper microbial balance in the gut.

It has also been shown that lactic acid bacteria can influence enzyme activity in the gut, which may increase nutrient absorption by the animal. Bifidobacterium bifidum produces a DNA polymerase that has been reported to be important in the repair of damaged cells.

Reduction of Toxic Amines

Amines, produced by some intestinal microbes, are irritating and toxic, and have been associated with diarrhea. Lactic acid bacteria have been reported to reduce the level of amines in the gut, and to neutralize enterotoxins.

Competitive Exclusion

Certain strains of Lactobacillus may associate with the mucous layer of the intestinal villi. Both the outer surface of the bacterial cell and the mucous layer are highly charged because of their amino acid and carbohydrate composition. These charges may interact to form an association between the bacterial cell and the intestinal site. This blocking of the intestinal site by a desirable organism prohibits a pathogen from adhering there. It has also been reported that beneficial bacteria can out-compete other bacteria for nutrients in the gut, thereby dominating the colonization of the intestinal tract.

When to use DFMs

The effectiveness of DFMs depends on when they are used. The best response is observed during the following situations:

At birth – The intestinal tract of newborns is basically sterile, which provides the best opportunity for introducing the beneficial bacteria found in DFMs. In several farm trials conducted through the University of Wisconsin, Holstein calves received a Lactobacillus and Bacillus DFM in their colostrums and milk replacer. The treated calves exhibited improved starter intake, weight gain and feed efficiency, and less incidence of scours.

During weaning or other diet change – At weaning, a young animal’s digestive system is not fully developed to efficiently change from milk to plant-based rations, which can result in poor feed intake and weight loss. A University of Nebraska research study reported that early-weaned pigs fed Bacillus exhibited 6%-9% improvements in feed efficiency and gained more weight.

During periods of stress – Handling, shipping, vaccination, weather changes and extremes, surgery and other situations can put stress on the animal, resulting in reduced appetite and feed intake and weight loss. In a trial at the University of Illinois, steers were shipped from Missouri, vaccinated, and then fed a Lactobacillus and Bacillus DFM daily. ADG (average daily gain) and total feed intake were significantly improved in the treated cattle. A 27% reduction in sick animal days was also reported.

After antibiotic therapy – Antibiotic treatment often lowers the number or growth of Lactobacillus and other beneficial microbes in the digestive tract. DFMs assist in the replenishing of these beneficial bacteria, resulting in a quicker return to a balanced intestinal microflora.

Daily feeding – Since many stressful situations can’t be anticipated, daily feeding of a DFM is recommended as a preventive measure. DFMs have been shown to improve animal performance and health when included in the diet.

Not all bacteria are alike; different strains of the same genus species, i.e. Lactobacillus acidophilus, can have different characteristics. When choosing a DFM, it is important to evaluate the microbial strain and the manufacturer.

Due in part to the recent popularity in both probiotics and DFMs, marketplaces have been pushing for a new level of industry standards and practices. While DFM manufactures must guarantee the number of microorganisms present in their products (which are enumerated using laboratory tests) they also have driven the next generation of manufacturing protocol.

Choosing a Good DFM

Evaluating the Manufacturing Company

An effective DFM product should be manufactured by a reputable company that:

• Has a core competency in all aspects of microbiology including the selecting, growing, harvesting, and stabilizing of microbial cultures

• Has a modern food-grade manufacturing facility that follows FDA guidelines and practices

• Has highly concentrated and stable products that do not require refrigeration

• Meets all HACCP food safety criteria

• Guarantees the level of viable organisms

• Has conducted extensive university research to support product effectiveness

Evaluating the Bacteria

An effective DFM product should contain strains that:

• Have fast growth rates and metabolic cycles

• Are acid and bile resistant

• Out-compete other intestinal organisms for nutrients

• Have a complex enzyme system

• Resist inhibition by other intestinal organisms

• Are effective in several animal species

Learn more:

To learn more about direct fed microbials, contact (add hyperlink to Contact here) your MojoMoo representative who can help ensure your cows are getting the most from their feed sources and your investment.