Before turning to new and often costly alternatives, it makes sense to rely first on proven methods. For more than a decade, the livestock industry has been working to remove antibiotic growth promoters from feeds.
In the U.S., some producers are moving toward “no-antibiotics-ever” systems, meaning birds are not treated even when sick. Because coccidiostats are also classified as antibiotics there, this shift has created serious challenges, since there are few true substitutes. Fortunately, this classification does not apply everywhere, including much of the EU.
This discussion concerns antibiotics that act against bacteria, not coccidia. Drawing from extensive field experience and research, the following six categories of additives are the most reliable starting points before experimenting with newer approaches.
Organic acids
Used for decades, organic acids can replicate the growth-promoting effect of antibiotics in healthy birds, though they cannot cure disease. They work best in blends and at higher inclusion levels than are commonly used. Selecting the right mix depends on each farm’s specific bacterial challenges. They may perform even better when combined with phytogenic compounds, although this needs further study.
Copper and zinc
Zinc oxide is ineffective in broilers, but copper sulfate can help and is still permitted within regulated limits. Modern, more bioavailable forms of copper and zinc can improve performance and premix stability at low doses. Because regulations vary by region, it’s essential to confirm legal limits before use.
Probiotics
Many poultry nutritionists consider probiotics the top investment when replacing antibiotics. They don’t kill harmful bacteria directly; instead, they promote beneficial microbes that crowd out undesirable ones. Not all products are equal, and results can vary. Probiotics are most effective when paired with ingredients that serve as food for them, though this synergy is often overlooked.
Feed-grade amino acids
While they don’t influence microbes directly, these amino acids allow crude protein levels to be lowered while still meeting nutritional needs. Less excess protein means fewer nutrients available for pathogenic bacteria, which rely heavily on protein. In some regions, however, lower-protein feeds are viewed skeptically, limiting one of the most powerful tools available.
Fiber
Generally, nutritionists agree that insoluble fiber helps manage moisture and digesta flow in the upper gut, while fermentable fiber supports beneficial bacteria in the lower gut. Yet there is little agreement on how to measure these fibers or how much to include. The ideal balance likely differs between healthy and challenged birds, and practical guidance is still evolving.
Enzymes
Enzymes indirectly support gut health by breaking down complex carbohydrates into simpler forms that beneficial bacteria can use. Proteases also improve protein digestibility, reducing nutrients available to harmful microbes. Their impact is usually modest on their own and becomes meaningful mainly when combined with other strategies.
Conclusion
No single product can completely replace antibiotics. Effective programs rely on thoughtful combinations tailored to each situation. Although transitioning away from antibiotics adds cost — and those costs are not easily passed on to consumers — the best approach is to work with proven tools while carefully evaluating promising new options.