Have you eaten your yogurt today? Has your doctor suggested you include a source of probiotics in your daily diet? If so, you certainly are not alone. Probiotics, also known as direct-fed microbials (DFMs), are sources of live, beneficial microorganisms, typically specific strains of bacteria or yeast.
In human health and nutrition, professionals and consumers increasingly recognize the benefits of some probiotics for improving digestion, health of the gastro-intestinal tract and overall immunity. The same applies to cattle production where, while not new, probiotic use is gaining credibility and acceptance.
In the past, probiotics sometimes got a “bad rap” among beef producers, largely because of some products that were big on marketing claims but short on research data demonstrating results. Today, though, a growing body of scientific evidence shows benefits of a variety of microbial products in terms of rumen health, immunity, feed efficiency and overall performance. These responses become particularly attractive as FDA guidance is resulting in the removal of production claims from most feed-grade antimicrobials and pressure mounts to reduce the use of antimicrobials for prevention of disease in food animals.
Generally, probiotics used in cattle production fall into categories of yeast-based products using strains of Saccharomyces cerevisiae, or bacterial products such as Lactobacillus acidophilus, Megasphaera elsdenii or combinations of microbes such as in Bovamine, which combines Lactobacillus acidophilus and a lactic-acid-utilizing bacterium Propionibacterium freudenreichii.
A body of research
Kevin Miller, PhD, is director of technical services for MS Biotec, the manufacturer of Lactipro. In summarizing research on DFMs, he says multiple types and strains have been shown to alter gut microflora, improve digestion, compete against pathogenic bacteria and aid in host immune response. Despite some inconsistencies, a growing mass of data suggests that DFMs are a viable means for improving performance and health of cattle.
Data have shown benefits of DFMs during the post-weaning period, Miller says. Weaned heifers fed a 63 percent forage diet containing Aspergillus oryzae (Amaferm, Biozyme Inc.) gained 22 pounds more over the first 28 days than heifers that were not fed Aspergillus oryzae. Over the entire 84-day study, feeding Aspergillus oryzae increased average daily gains (ADG) by 5 percent and improved feed efficiency (FE) by 6 percent.
Similarly, the addition of a yeast product (Diamond V-XPC) to a coarse-texturized complete feed improved gains of ranch-weaned calves by 8 percent during a 28-day post-weaning period.
Miller adds that multiple studies on the use of DFMs in feedlot receiving programs have shown improvements in ADG and FE, and reductions in morbidity.
Charles Jamison, DVM, ABVP, technical services manager for Nutrition Physiology Co., outlines trial data on the company’s well-established Bovamine products, which combine Lactobacillus acidophilus and Propionibacterium freudenreichii.
· · In a summary of 13 feedlot trials with Bovamine Defend, live finished weights for treated cattle averaged 10 pounds heavier than those for control cattle, while carcass weights averaged 6 pounds heavier. ADG was 2.1 percent higher in treatment cattle, and researchers noted similar results with a 1.7 percent ADG improvement in large-pen trials in Kansas, Texas and California.
· In an Arizona feeding trial, first and second pull rates were reduced by about 40 percent.
· The product also has applications as a pre-harvest food-safety intervention, with up to 99 percent reduction in E. coli O157 concentration in feces in feedyard trials. Several trials also have shown 30 to 50 percent reductions of non-O157 pathogenic E. coli strains, and up to a 90 percent reduction of Salmonella in cattle lymph nodes.
· In five trials at different universities, hot-carcass weight in finished Holstein steers improved an average of 16 pounds.
Kerry Barling, DVM, PhD, global manager of beef technology at Lallemand Animal Nutrition, says his company has conducted extensive research on its probiotic products for cattle production, which include:
· ProTernative (Saccharomyces cerevisiae boulardii strain I-1079) is a naturally occurring active dry yeast shown to help reduce the negative impact of stress in cattle.
· Levucell SC (Saccharomyces cerevisiae CNCM I-1077) is a rumen-specific active dry yeast selected to help optimize rumen function.
· Micro-Cell LA contains Lactobacillus acidophilus BT1386, which exhibits significant probiotic properties in the lower gut of beef cattle fed all types of rations.
Barling says that in research at Texas Tech University, Lallemand’s ProTernative yeast product significantly improved dry-matter intake during the stressful receiving period and consistently reduced BRD morbidity rates by about 40 percent.
Research has shown the company’s Levucell product improves rumen maturation in nursing calves and increases rumen pH and fiber digestibility and optimizes rumen function in beef cattle of all ages. In controlled trials with growing cattle with higher than 30 percent neutral detergent fiber diets, treatment cattle averaged 5.2 percent better feed-to-gain ratio and 6.7 percent higher ADG. In finishing trials, treatment cattle averaged 5.6 percent better feed-to-gain ratios on conventional diets and 4 percent better on natural diets.
A food-safety pathogen-reduction trial performed by North Dakota State University found that cattle fed Lallemand’s bacterial product, Micro-Cell LA, had significantly less fecal shedding of E. coli O157:H7 and significantly lowered risk of new infections of Salmonella than did control cattle, based on natural exposure to these pathogens in a feedlot pen environment.
Lactic acid is produced in the rumen when highly fermentable feedstuffs are consumed and can be problematic if cattle are not accustomed to consuming highly fermentable feedstuffs, Miller explains. Accumulation of lactic acid decreases rumen pH and leads to disorders such as acidosis and founder.
MS Biotec’s Lactipro product is a live culture of Megasphaera elsdenii, a lactate-utilizing bacterium with applications for improving rumen health and digestion in several classes of cattle and production stages. The product is administered in a liquid drench. In newly received calves fed a 55 percent concentrate diet, the product improved intake by 7 percent, ADG by 19 percent and FE by 15 percent during a 64-day 2013 receiving trial. In addition, morbidity was 30 percent lower for treatment calves.
Miller says much of the recent interest and growth in demand for Lactipro comes from operations raising young dairy calves, where clinical research has shown the product aids in rumen development.
Miller also notes beef producers who graze cattle on crop residues have found Lactipro beneficial, especially in fields where hail damage or other factors have resulted in more grain available than usual. Treating cattle with Lactipro prior to turnout on these fields helps prevent digestive problems without the owner resorting to laborious measures such as hauling in round bales for roughage, pulling cattle off the residue fields at night or adding bicarbonate to water.
Practical field application
Feedyard consulting nutritionist John Beckett, PhD, operates Beckett Consulting Company and develops receiving and general nutrition programs for a variety of feedyards.
He says the yeast-based probiotics, in his tests and practical experience, produce a health response. Several of his feedyard clients also have used Bovamine for years, and Beckett has seen a performance response to the product. In a commercial feedyard setting, he says, a small improvement in performance can be difficult to measure and even more difficult to attribute to a single variable such as feeding a DFM. However, he notes that Bovamine costs about a penny per head per day, so for an animal on feed for 180 days the cost is about $1.80. At today’s fed-cattle prices, just a 2-pound average improvement in finished weights easily provides economic justification for using the product.
Just as importantly, Beckett cites the scientific data supporting the benefits of Bovamine as a pre-harvest food-safety tool. From an industry standpoint, he believes using such a tool will benefit consumers and, thus, benefit producers in the long run.
He sometimes recommends other bacterial products such as Lactipro and believes the product has merit. One of his client yards routinely uses Lactipro in the receiving program, and Beckett believes it is particularly useful for cattle coming into the feedyard directly off grazing programs, with little to no exposure to high-energy feeds. Those cattle are at highest risk for acidosis and other digestive problems.
Miller agrees, saying feeder cattle coming out of backgrounding programs or crop-residue grazing where they have consumed some grain along with forages should have higher natural populations of lactate utilizing bacteria in their rumens and less need for inoculation with a product such as Lactipro.
Barling says recent years have brought a significant change in perceptions regarding the role of probiotics in cattle production. Twenty to 30 years ago, some companies were marketing probiotic products for livestock, but there was little to no trial data or other information to support their claims. Some producers used them, primarily to treat underperforming cattle, with the idea they didn’t cost much and didn’t seem to do any harm.
Today, science backs up the roles of specific microbial species and strains in supporting digestive health and feed utilization. Barling notes that specific strains of live yeast can help offset the effects of stress in cattle due to weaning, transport and commingling. This tends to help keep them on feed, meaning less morbidity, less treatment and lower mortality.
Barling stresses that probiotics cannot replace antibiotics, particularly in treating sick cattle, but can help prevent disease and perhaps serve as an adjunct therapy to limit severity and duration of disease, thus helping reduce overall antibiotic use. Probiotics also can help offset the consequences of antibiotic treatments by restoring the balance of microbes in the gut. And as consumer interest in food safety, antibiotic use and animal welfare increases, he says the industry needs technologies that will benefit animal health and production while maintaining consumer trust.
Probiotics tend to have fairly specific sites of activity, with some working in the intestine to improve gains and feed efficiency or reduce the incidence of food-safety-related pathogens. Others work in the rumen to enhance digestion and modify pH levels.
A key to successful use of these products, Barling stresses, is to know their source and work with your nutritionist or veterinarian to review supporting research. All yeasts are not the same, nor are all bacteria, even within a species. Barling notes that Lallemand’s ProTernative product contains Saccharomyces cerevisiae boulardii strain I-1079 as the active ingredient. S. cerevisiae is a common yeast species, with strains used for brewing, winemaking, baking and other purposes. The specific strain, however, has unique health benefits well-documented in scientific literature. So, he stresses, look for data from reputable sources in selecting these products.