Considerations when choosing direct-fed microbials for poultry
By Carla Price, PhD
In-feed antibiotics are highly regulated and help ensure the health and welfare of poultry, but many poultry integrators are feeling the pressure from foodservice companies and consumer groups to reduce or even eliminate the use of these valuable medicines.
This trend has created many challenges for producers, particularly operations that have elected to go antibiotic-free. The biggest, most consistent issue is the effect of clostridia and resulting necrotic enteritis (NE).
As producers are well aware, the subacute form of NE may cause minimal mortality but it impairs performance; acute NE results in even greater performance losses due to ongoing malabsorption problems and leads to morbidity and, sometimes, high mortality. Other concerns in antibiotic-free production are Salmonella and Campylobacter, which pose a food-safety risk to consumers.
There are a number of potential products now being marketed as feed ingredients intended to “replace” in-feed antibiotics. Among these are organic acids, essential oils, yeast extracts, yucca extracts, and probiotics and prebiotics.
All of them have pros and cons, including odor, stability during feed manufacturing, stability of the product in feed prior to consumption, handling issues and cost.
Probiotics and prebiotics
At this time, probiotics and prebiotics have gained the most traction in the poultry industry and are the most likely to be consistently cost-effective.
Probiotics can be loosely defined as beneficial microflora that improves the health of the host. Prebiotics are defined as indigestible (to the bird) feed ingredients that help maintain the health of the beneficial microflora supplied in the probiotic.
Several probiotics are currently available to the poultry industry, and the claims associated with them range from improved weight gain, feed efficiency and livability to improved immune function and competitive exclusion of undesirable bacteria — particularly Salmonella and Campylobacter. How does a poultry integrator choose which probiotic to use, test and evaluate?
Some integrators search for a product to help manage a specific concern, such as NE. High Salmonella counts at processing and resulting pressure from regulatory agencies are sometimes the incentive for considering probiotics. Other integrators try to compare the efficacy of probiotics to in-feed antibiotics in preparation for producing antibiotic-free meat production. Yet other integrators choose a probiotic that’s supposed to improve immune function in the face of other health issues, such as viral diseases or high mycotoxin levels in feed.
Cost per pound
More often, as it is with all feed-inclusion products, the primary deciding factor in selecting a probiotic will be cost per pound of meat production. Probiotics are evaluated based on the initial cost and expected improvements in weight gain, feed efficiency and/or livability, resulting in improved feed costs per pound of meat.
Most probiotics are priced at or below the price of in-feed antibiotics. From experience, I can tell you that the least expensive probiotics may not be the most efficacious, but the same also may be true of the most expensive ones. In addition, I’ve seen one product work well at one location within a company but not at all of the company’s locations. I’ve also seen probiotics that worked well for one company but not for others, even when they’re in the same area. So again, how can integrators decide on a probiotic?
Beyond performance and cost of the probiotic, experience with the vendor must come into play. Is there good customer support, including reliability and assistance with assessing flock performance? It’s also a good idea to consider how extensively the product is currently in use within the poultry industry.
Now to prebiotics: Fewer of them are commercially available to the poultry industry and, consequently, there’s less hard data available. However, a case can be made that the use of a prebiotic with a probiotic may enhance the effects of a probiotic. Theoretically, a prebiotic allows the probiotic to more easily colonize the gut of the bird, thereby optimizing the effects of the probiotic in performance and competitive-exclusion situations.
The criteria for choosing a prebiotic would be the same as it is for selecting a probiotic: Consider economic and performance factors that improve feed cost per pound of meat over and above the costs of the product.
The possible final case for the use of probiotics and prebiotics gets back to consumer sentiment. A brief Internet search for these products, particularly probiotics, demonstrates that they are aggressively marketed to average consumers. In North America alone, probiotic sales increased from US $2.6 billion in 2010 to a projected US $3.5 billion in 2015. This indicates that an increasingly agriculturally unaware consumer market is likely to be comfortable with probiotics and will be equally comfortable with their use in animal agriculture.
Dr. Price, formerly a corporate nutritionist at Sanderson Farms, is an independent poultry nutritionist based in Mississippi, who provides nutrition consulting services to poultry integrators.
 Sales of probiotic products worldwide from 2010 to 2015 by region (in billion US dollars). http://www.statista.com/statistics/252941/probiotic-products-sales-worldwide-by-region/ Accessed February 20, 2015.