More intensive industrial production has placed greater demands on birds and given rise to several challenges related to gut health, including unspecific dysbiosis problems, reduced nutrient digestibility and impaired barrier function. These issues put pressure on farm profitability and explain, at least in part, the motivations for sub-therapeutic application of antibiotics for disease prevention and growth promotion.
A recent scientific study notes that the poultry industry’s global consumption of antibiotic growth promoters (AGPs) is three times higher than that of cattle: 45 mg/kg vs 148 mg/kg (Van Boeckel et. al. 2015). Without indicating any relationship between resistance level and antibiotic usage, Teillant and Laxminarayan (2015) point out that recommended dosage of sub-therapeutic antibiotics has increased over last 60 years, from 10–20 g/ton in the early 1950s to 40–50 g/ton in the 1970s, to 30–110 g/ton nowadays.
New ways to promote growth
The experiences in countries that were early to adopt AGP bans, such as Sweden in 1986 and Denmark in 1998, demonstrate that while a move to antibiotic-free production is not without short-term challenges, these can be overcome and flock performance can reach even higher levels. Replacing AGPs relies upon a holistic approach to improve animal health status and performance through better management, biosecurity measures, vaccination programs, diagnostics and feeding strategy.
Since feed costs account for a significant part (up to 70%) of total production costs, feeding strategy is a crucial point. Organic acids, phytogenic feed additives (botanicals, or PFAs), probiotics (direct-fed microbials, or DFMs) and prebiotics have all been identified as potential in-feed antibiotic replacements. They work in different ways (various modes of action) in order to prevent the proliferation of harmful bacteria, to promote health and immune status, and to enhance animal performance, e.g. by influencing a bird’s anti-inflammatory response.