Such AGP-free approaches are further driven by increased consumer demand for antibiotic-free beef in both the retail and restaurant industries. In the U.S., many retailers offering such niche-market products are forced to get meat from overseas, citing that there is not enough AGP-free beef produced in the U.S. to meet demand.
This would seem to provide a tremendous opportunity for beef producers in the U.S.
There are still many roadblocks that stand in the way of the “would-be” AGP-free producer. Most important is the concern that in order to maintain animal health through to market weight, AGP-free beef cattle must be fed diets with higher forage and lower concentrate levels.
The associated changes in feed cost and feed formulations, coupled with losses in performance and production efficiency, may make AGP-free beef production price-prohibitive.
However, a quick review of available technologies suggests it is possible to produce beef without antibiotics while maintaining standard dietary concentrate levels and the performance associated with industry-wide practices in the beef cattle industry.
The development of effective AGP replacement programs will most likely not be simple and will require strategic programs that result in changes in feed formulation, the use of non-antibiotic feed supplements, and changes in biosecurity and management practices. Several aspects of nutrition and supplementation strategies are becoming useful in this respect.
Mineral management: Strengthening the immune system
Resistance to disease and optimal function of the immune system are highly dependent on a supply of nutrients. Important nutrients include sufficient protein, energy and micronutrients.
As a result, the goal of AGP-free production is to strategically use functional nutrient forms to support the animal immune system at all stages of life. Specific trace mineral supplementation strategies can be used as functional tools to help boost immune function and disease resistance.
Simply put, healthy animals do not need antibiotics if the immune function is appropriately adapted to protect the animal. A solid nutritional foundation for the animal’s optimal immune function requires particular focus on mineral management and gut health, and these can be delivered to the animal in a tailored feeding program.
Trace minerals are particularly important to the function and regulations of the immune system. As a result, appropriate mineral nutrition is critical to optimal immune function.
Unfortunately, it is difficult to ensure that cattle consume sufficient minerals. This is due to the fact that inorganic mineral salts, the form in which they are most often fed, tend to interact with each other in the diet and with other minerals in the water supply, ultimately making the inorganic minerals less available to the animal.
Organic minerals can be used to ensure the immune system is adequately supplied with trace minerals, which is why they are becoming increasingly important tools for improving the health of challenged feedlot cattle.
By being complexed with organic molecules, mineral preparations are protected from adverse interaction in the gut, making them more bioavailable to the animal.
The latest research in this area suggests these alternative forms of minerals may also prevent unintended oxidative damage to animal tissues associated with inorganic mineral salts, resulting in other benefits to animal health, performance and product quality.
Gut health management: Creating proper balance for improved gut health
Another central objective of a proper nutritional foundation for AGP-free beef production is to ensure optimal gut health. The two fundamentals of gut health in cattle are rumen functionality and microbial balance.
Rumen functionality
Ensuring a functional rumen is critical to the digestion of feed and to providing energy and high-quality protein to the animal. Any nutritional strategies that adversely affect rumen function can seriously influence production efficiency and animal health.
Low levels and prophylactic antibiotic applications have been used as rumen modifiers for decades to improve efficiency, maintain health and regulate rumen function.
However, recent research has shown there are alternative strategies that can be used to effectively manipulate rumen function without antibiotics.
One of these strategies is the use of direct-fed microbials. These are live organisms supplemented in the feed to modify the fermentation processes in the rumen and to support beneficial microbial population in the gastrointestinal tract.
Specific strains of yeast cultures are particularly effective at maintaining a stable rumen pH, enhancing the digestion of feed and improving the efficiency of microbial protein production. This is critical when feeding the typical high-energy commercial feedlot diets.
Another strategy for manipulating rumen function is the use of enzymes as tools for modifying ruminal bacterial populations and overall rumen function. These generally require diet-specific applications but are often as effective as antibiotics as tools for manipulating microbial activities.
Research is also ongoing on the use of specific plant-derived compounds and essential oils to beneficially mitigate rumen function.
Again, the selective activity of many of these materials can be as effective as AGPs and may be used to enhance specific types of antimicrobial activities and changes in ruminal microbial populations.
Gastrointestinal balance
There is a fine balance in the intestine between beneficial and pathogenic organisms. When this balance is disturbed, opportunistic bacterial infections in the intestine can wreak havoc on the efficiency of digestion and absorption of feed.
Antibiotics have traditionally been used sub-therapeutically or in prophylactic strategies to control potentially pathogenic gut bacteria in an attempt to prevent intestinal infections. These are particularly important in stressed cattle.
However, these antibiotics do not necessarily differentiate between pathogenic bacteria and the beneficial bacteria essential for the proper function of the intestine. The results can compromise normal intestinal balance and the long-term health and performance of the animal.
Antibiotic-free strategies help address such issues by supporting a healthy microbial population of bacteria in the gastrointestinal tract. Prebiotic technologies, such as associated supplements containing specific fractions from yeast cell wall, are designed to do just that.
By supporting populations of beneficial micro-organisms, preventing colonization by pathogens and modulating immune function, these supplements have been shown in numerous studies to significantly improve animal health and performance in animals maintained on AGP-free programs.
Building the nutritional foundation of AGP-free production: A tailored feeding program
The foundation for an effective AGP-free program can be built using the appropriate application of existing nutrition strategies such as those developed with organic trace minerals, direct-fed microbials, prebiotics and enzymes.
However, these nutritional technologies must be delivered to the animal properly through a tailored and targeted feeding program. The timing of each of the interventions is paramount to their success.
More research has validated these approaches. A recent trial examined the use of one such nutritional program for replacing the traditional use of Monensin and Tylosin in feedlot rations.
While such programs require specific attention to feed formulation and management, they provide alternative, cost-effective feeding strategies that produce similar feedlot performance and carcass composition when compared to traditional AGP programs.
Such programs also improve water-holding capacity of the resulting meat products, leading to greater overall consumer acceptance.
It is clear from this work that AGP-free beef production is achievable through targeted support of the immune system and establishment of optimal gut health without antimicrobial supplementation.
These types of strategies will provide the tools needed to effectively introduce AGP-free programs in beef production systems. 
Dr. Karl Dawson is vice president and chief scientific officer at Alltech.
References omitted due to space but are available upon request. Click here to email an editor.
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Vaughn Holder
- Beef Specialist
- Alltech
- Email Vaughn Holder
