The fear of loss in animal performance and profitability can make farmers and integrators apprehensive to reduce antibiotic growth promotors (AGPs) in animal diets. However, a better understanding of nutritional stressors and appropriate biosecurity measures can provide reassurance, that life and profitability will go on with antibiotic-free feeding.
In the US many farmers use antibiotics to treat, prevent, and control animal diseases and increase the productivity of animals and operations. However, there is concern that routine antibiotic use in livestock will contribute to antimicrobial-resistant pathogens, with repercussions for human and animal health. Given these concerns, pressure to limit antibiotic uses for purposes other than disease treatment is mounting. Maintaining a profitable future is looking promising with sound management and new alternatives to AGPs.
The U.S. Centers for Disease Control and Prevention (CDC) estimates that antibiotic resistance is responsible for more than 2 million infections and 23,000 deaths each year in the United States (CDC 2013).
Earlier this year, researchers have found a person in the United States carrying bacteria resistant to antibiotics of last resort, for the first time. According to a top US public health official this could be the end of the road for antibiotics. Another report mentions that the “new superbug” MCR—a gene, carried by gut bacteria, that confers resistance to the absolutely last resort antibiotic Colistin—has been in the United States for at least a year.
Relationship between use and resistance
In their 2015 report «The state of the world’s antibiotics» the US Center for Disease Dynamics, Economics & Policy states that the greater the volume of antibiotics used, the greater the chances that antibiotic-resistant populations of bacteria will prevail and that antibiotic resistance is a direct result of antibiotic use.
Two trends are threatening to increase global antibiotic consumption and therefore the risk for antibiotic resistance: First, rising incomes are increasing access to antibiotics, which is increasing the use in the human population. Second, the increased demand for animal protein and resulting intensification of food animal production is leading to greater use of antibiotics in agriculture. In the United States an estimated 80 percent of all antibiotics consumed are used in food animals (U. S. FDA 2010).
Changing consumer demands in the US
Consumer awareness of antibiotic use in livestock production has increased. One indication of the growing demand for products raised with limited antibiotic use is a Consumer Reports 2012 survey of 1,000 U.S. residents finding that 86 percent of consumers would like the ability to buy meat raised without antibiotics at their local supermarket. This survey found that over 60 percent would be willing to pay an additional $0.05 per pound for meat raised without antibiotics, and 37 percent were willing to pay an additional dollar per pound.
Major retailers and restaurant chains such as McDonalds, Subway, Panera Bread, Chipotle, Applegate, Whole Foods and Costco have picked up on this and are taking a proactive stance to eliminate the use of antibiotics over a given time frame. For instance, Chic-fil-A, the largest U.S. chicken chain by domestic sales volume, has committed to serve only 100 percent antibiotic-free chicken by 2019. The company announced that as of March 2015, it had already converted 20 percent of its chicken supply.
In 2013, the U.S. Food and Drug Administration (FDA) issued final guidance on voluntarily phasing out the use of medically important antibiotics (those important for therapeutic use in humans) for livestock production purposes.
How to stay profitable
For farming operations, the biggest fear of reducing the use of antibiotic growth promotors in feed or stop their preventive use entirely is that it will reduce economic returns from animal production. However, there is research showing that antibiotics used for production purposes generally have limited effects on the productivity of raising livestock at the farm level and the effect has been decreasing significantly over time (Table 1).
Latest research in Belgium and the Netherlands has shown that reducing the use of antibiotics in animal feed, does not endanger the economic situation of pig farms when biosafety measures and vaccinations are applied. On the contrary, in finishing pigs it can lead to €2.67 more profit per head.
In this research, there was an active emphasis on improving biosecurity status, the vaccination scheme and farm management. On average, the farms received advice for a timeframe of roughly 8 months. While there was a reduction of use in antibiotics by 52% from farrow to slaughter, there was a significant increase in biosecurity. At the same time there was higher daily growth (+7.7 g/d) and a reduced mortality during finishing (-0.6%).
Success will depend on operations
In practice, the effects of eliminating antibiotic growth promotors from animal feed are likely to vary considerably and will depend on current practices and external conditions (Laxminarayan et al. 2015). Operations with better sanitation, less crowding, and more modern production practices are likely to be affected less than older operations that have not updated their facilities and practices. In Sweden, the ban on growth promoters had a greater effect on producers with lower hygiene standards (Wierup 2001).
Keeping up with the top players
Major meat producers such as Smithfield foods, Seaboard foods, Tyson and Perdue, Pilgrim’s Pride, Foster Farms have already taken steps to reduce the use of antibiotics in their operations and/or even to introduce antibiotic-free production lines. Perdue announced in July 2015 that more than half of their birds are produced antibiotic-free.
A global feed survey carried out by WATT revealed that 58 percent of respondents consider the elimination of antibiotic growth promotors in feed as a critical obstacle to overcome in 2016 and 65 percent of the participants in the survey report that their company is actively testing or using alternatives to AGPs.
The above trends are clearly following consumer pressure and/or government regulation mentioned earlier.
Ready, steady, agile – new alternatives to go antibiotic-free
Agility is the capacity to anticipate change, respond, adapt quickly and thrive in a changing environment. The key question is whether the natural ability of animals to adapt to nutritional challenges and other stressors can be deliberately accelerated and optimized to benefit animal performance and the agility of animal production systems.
Research in genetic selection shows that improving the ability of animals to cope with stressors is a better way of improving performance than selecting only for increased growth potential. Genetic selection is certainly going to play an important role for advancement in this capability of the animal. However, nutritional strategies supporting the speed and efficacy with which the animal adapts to stressors will bring a more immediate competitive advantage in animal production.
A new approach to nutrition is to support the agility of the gut, i.e. its ability to adapt to nutritional stress factors efficiently. The agile gut is quicker to respond to prevent negative stress reactions, such as oxidative stress, loss in appetite, increased gut permeability and inflammation, which can cause waste of metabolic energy and increased risk of disease.
Agile nutritional concepts are designed to empower animals to adapt to a variety of nutritional stress factors, for more robust and energy-efficient animals. They rely on bioactive substances mainly derived from plants, known to prevent some of the negative stress reactions seen at the cellular level and offer a safe alternative to AGPs.