Sustaining animal resilience post-AGP

Increased animal resilience supports the reduction in antibiotic use and improves sustainability within the livestock industry.

Antibiotic use as antibiotic growth promoters (AGPs) has allowed to increase food production at lower cost but antimicrobial resistance (AMR) has also a cost both monetary and human. This observation pushes countries to adopt more strict regulations or antibiotic reduction programs. In addition, final consumers are expecting more natural and healthier products. They are more inclined towards animal welfare and environmentally friendly products and are increasingly aware of AMR issues. This pressure on the animal sector obliges the chain to adapt and find solutions to reduce their antibiotic use.

The animal production sector should have realistic expectations on antibiotic alternatives potential. For example, feed additives are not able to cure an upcoming disease. The experience in the EU with the AGPs ban in 2006 taught us that an integrated approach including strict government regulations, improved farm management, general animal health status and production processes minimises the effect of the ban on performance drop. The whole industry was worried but finally the efficacy of AGPs was very limited in terms of growth promotion or feed efficiency. Before 2000s, studies comparing performance with and without AGPs were showing very high performance increases when fed AGPs. A meta-analysis of more than 1000 experiments showed that on swine, AGPs improved the feed efficiency by 6.9% in average, and daily gain by 16.4 % but the effect has changed over time. Indeed, studies after 2000 showed lower productivity gain. In 2002, Engster et al showed that the inclusion on AGPs on feed allowed only an increase in daily gain of 0.8% and 1% for the feed conversion ratio.

This apparent decrease of AGP efficacy has various causes, upon them optimisation of production conditions. Indeed, hygiene practices, genetic potential, nutrition and health status of animals are ensuring optimal production conditions. Functional feed additives can be good levers to maintain high performance, while supporting a responsible use of antibiotics, by sustaining animal resilience.