By Casey L. Bradley, Public Policy Committee Member
In December 2016, the European Medicines Agency’s Committee for Medicinal Products for Veterinary Use (CVMP) proposed a ban of pharmacological levels of zinc oxide in swine rations. The CVMP has concluded that the treatment benefits of zinc oxide (ZnO) for the prevention of diarrhea in pigs do not outweigh the environmental risk associated with its use. However, effective measures to manage and reduce the accumulation of zinc in the environment could not be identified.
Furthermore, the CVMP acknowledged a risk exists for co-selection for antimicrobial resistance associated with the use of zinc oxide, but currently the risk was not quantifiable. Based on its scientific conclusions, the committee recommended withdrawal of marketing authorizations for zinc oxide products.
A number of professional associations related to pig production have already said they will fight a future ban on the use of medicinal ZnO in animal feed, as it would remove a key tool for controlling post-weaning diarrhea.
In most EU member states ZnO is licensed as a medicinal product for use at 3.1 kg/t feed to provide 2500 mg/kg zinc for 14 days post-weaning. It is licensed for the treatment and control of post-weaning diarrhea and its widespread use as a prescription-only medicine (POM) shows the effectiveness it continues to have in controlling this common post-wean challenge.
Although the mechanism by which ZnO elicits this effect is still poorly understood, its link to maintaining tight junction integrity indicates its importance in supporting gut health. The effectiveness of ZnO in controlling post-wean diarrhea becomes even more critical as it is playing a significant role in reducing in-feed antibiotic use in pig production.
Recently Pig Progress (February 2017) published an article by fellow ASAS members, Pete Wilcock, Carrie Walk, and Ian Wellock, discussing the ramifications and potential alternatives to such a ban.
The effectiveness of ZnO in controlling post-wean diarrhea becomes even more critical as it is playing a significant role in reducing in-feed antibiotic use in pig production. For example, data from one major UK starter feed manufacturer shows veterinary prescriptions for antibiotics in combination with ZnO at medicinal levels has declined; falling from 61% of all UK feed manufactured at the beginning of 2016 to 37% in December 2016. In contrast there has been an increase in ZnO only POMs from 26% to 40% of all feeds manufactured over the same time period. Antibiotic only POMs have remained unchanged at 3.5%. This change in POM’s associated with antibiotics clearly demonstrates the importance ZnO has had in allowing for this rapid reduction in antibiotic use in starter feeds. Any removal of medicinal uses of ZnO may well slow down, if not reverse, the reduction of antibiotic use currently seen as the key focus within the pig industry as the best way of reducing the potential, although limited, risk of antimicrobial resistance.
The authors also discuss opportunities to reduce overall ZnO consumption in swine without banning medicinal use of ZnO in young starter diets. With the potential alternative plans for ZnO reduction in swine diets, medicinal or pharmacological levels of ZnO could still be maintained while aiding in producers’ ability to reduce and eliminate antibiotics within production systems.
This situation is a great example of how ASAS members can continue to voice their professional, scientific-based opposition of unjust and damaging regulations developed in the absence of scientific evidence and imposed by uninformed legislation.