Background 13 comments

4 reasons why ZnO ban in pigs is unfortunate

The therapeutic use of zinc oxide (ZnO) should be banned and existing national registrations should be withdrawn also. That is the recommendation of the European Medicines Agency (EMA) to the EU Commission. Health expert David Burch shares his doubts.

The actual text of the recommendation of the European Medicines Agency (EMA) is as follows:

“The Committee concluded the referral procedure for veterinary medicinal products containing zinc oxide to be administered orally to food producing species. The matter was referred to the Committee by the Netherlands and France under Article 35 of Directive 2001/82/EC due to concerns related to potential risk to the environment and increase of prevalence of antibiotic resistant bacteria from the use of products containing zinc oxide.

The Committee adopted by consensus an opinion concluding that overall the benefit-risk balance for the products concerned by this referral is negative, as the benefits of zinc oxide for the prevention of diarrhoea in pigs do not outweigh the risks for the environment. The CVMP acknowledged that there is a risk of co-selection for resistance associated with the use of zinc oxide, but at the present time, that risk is not quantifiable .

The Committee therefore recommended the refusal of the granting of the marketing authorisations and the withdrawal of the existing marketing authorisations for veterinary medicinal products containing zinc oxide.”

Unfortunate decision for EU pig producers

This is a most unfortunate decision for the majority of pig producers in the EU, who use zinc oxide at high levels in their peri-weaning feed to control post-weaning diarrhoea. At a time when we are trying to reduce the use of antibiotics in pig medicine it is bad news.

Some personal experiences regarding the use of zinc oxide in feed:

1. Zinc oxide helps post-weaning diets

Back in the 90's a good farm got infected with Abbotstown Escherichia coli (O149). It was a clean farm and had a well controlled weaning shed, which had not had problems before. In spite of the use of antibiotics like trimethoprim/sulphonamide, neomycin, they did not stop the diarrhoea and increase in mortality to about 10%. Zinc oxide was added to the post-weaning diets and the problem disappeared.

Zinc oxide can help post-weaning piglets overcome E. coli-related diarrhoea. Photo: Henk Riswick.
Zinc oxide can help post-weaning piglets overcome E. coli-related diarrhoea. Photo: Henk Riswick.

2. Explosion of mortality without ZnO

I was carrying out a swine dysentery eradication on a farm and the local vet inadvertently forgot to prescribe the zinc oxide in the weaner feed and there was an explosion of mortality (2%) and diarrhoea and he was blamed.

3. Dirty weaners without zinc oxide

I was visiting a farm with respect to eradicating PRRS virus and enzootic pneumonia and noted the weaners were dirty and showing unevenness of growth, which lasted for 2 weeks. I have not seen this for years. I asked if he was using zinc oxide and he said he wasn’t. I have seen a similar farm in the Netherlands, where they do not use zinc oxide in the feed at all.

4. A 70% reduction of diarrhoea

The incidence of post-weaning diarrhoea in the UK since farmers switched to 4 week weaning and zinc oxide in the feed has reduced by nearly 70%.

Further reviews to ZnO are needed

If you are in a member state which allows the use of therapeutic levels of zinc oxide and want to retain it, then I suggest you contact your local representatives to contact their EU equivalent bodies – Copa-Cogeca, Fefac, Fefana, FVE, Epruma, IFAH-Europe to try and request that DG Agri and DG Sanco halt the decision until a further review can be carried out.

The benefits are very high for weaner pig health and welfare, EFSA (2012) has already passed a positive opinion on the environmental aspects of zinc oxide – no impact for 50 years and the EMA admit the antimicrobial resistance risks are unclear. I think the decision should be reassessed or the national registrations should be allowed to remain.

What do you think?


  • M. Varley

    I totally support David Burch's comments in relation to zinc. At the present time each piglet eats around 550 g of feed per day for 2 weeks post weaning when the zinc oxide is included at 0.3 %. You do the maths but this is not a lot of zinc at all. !! But the benefits in terms of diarrhoea control are known by every farmer in the EU.


    Dear David,
    As you know, David, for me this is a "fortunate decision" as long as the applicant does not submit data based on, yes expensive, Phase II studies requested as Zn is not degrated and is just accumulating in the ground and faeces This was known since years when I issued a report on the ERA ( environmental risk assessment) for medicines based on therapeutic levels of Zn ; this as case study for my degree in E.P.A (environment and animal production) at the veterinary school of Toulouse obtained in 2004. Every vet medicine has to implement to requirements of registration also a premix based on ZnO!! This is a very general comment; but I have comments to each of your 4 reasons!!
    Best regards,
    Bill VANDAELE, Dr Vet Med-Lic Zoot-E.P.A-MAVC Consultant in European Regulatory Affairs, Belgium

  • D J Kelliher

    At this juncture, I believe the role of protected encapsulated ZnO
    Needs To be more fully assessed even at the 150 ppm level in
    conjunction with appropriately formulated post weaning diets,
    As they are claimed to deliver the ZnO molecule intact and
    active to the small intestine , whereas at present ( subject to
    correction) the majority of the Zinc reaching the intestine is said
    to be in the form of the less active Zinc Chloride molecule ?

  • David Burch

    Thanks Mike for your practical support.
    Bill, could not some compromise be reached? In Spain they say put pig waste on a field every other year. This would halve the application rate. Did you take into account in your calculations the uptake by plants but in particularly corn crops that also need zinc to grow well?
    Dennis, I am not sure you are right here. Some will be converted to zinc chloride in the stomach but the bulk appears to go through unchanged. Experiments have been carried out with zinc chloride and completely different results were achieved though to be mainly associated with toxicity.
    Best regards David

  • JN Mr Gadd

    From John Gadd. I fully agree that this is a retrograde step imposed by people from a country with much low lying land and not much of it anyway to dispose of havy metals. Let them ban it under such circumstances and not penalise those pig producers who have ample disposable land area
    Blanket bans are nearly always poorly thought through and here is another of them.

  • David Burch

    Thanks John, much appreciated. I have come across another document that accommodated all the advised changes by the CVMP “Therefore, the CVMP recommended the granting of the marketing authorisations for the veterinary medicinal products referred to in Annex I with amendments to the Summary of Product Characteristics and package leaflet of the reference Member State. The amended Summary of Product Characteristics and package leaflet of the reference Member State are set out in Annex III.” So what has made them change their minds???

  • David Burch

    Advice suggests Member States can challenge this decision - “As per normal practice, the EU Commission will now consider the CVMP Opinion, and will decide whether the marketing authorisations for these medicines will be withdrawn, and if so, when. As you know, there will be further opportunity for EU MS to engage with the Commission on this proposal when it is discussed by the Standing Committee on Veterinary Medicinal Products, and this consultation will take place prior to the issuing of the Commission’s decision. Stakeholders with concerns relating to possible withdrawal of these products can also raise these with the Commission in the usual way.”

  • i wellock

    Thanks very much for the update David, much appreciated. Encouraging that we can perhaps have some open science led debate on this important topic before a final decision. kind regards Ian

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  • David Burch

    Wake up pig industry, this is the latest EU Government statement: - "It is acknowledged that the withdrawal of zinc oxide products is likely to require changes in pig farming practices to avoid increases in occurrence of diarrhoea at weaning and to ensure animal welfare and to prevent increases in the use of antimicrobials." Every week delay in weaning reduces sow productivity by 5%/annum. You will have to increase farrowing accommodation from 3 or 4 weeks to 6-8 weeks. This will potentially require doubling of farrowing accommodation at approximately 3000 Euros a place, to stand still. Then can you get planning approval - it can take up to 3 years for new buildings in the UK.

  • David Burch

    The EU Commission DG Sante are likely to have a Standing Committee meeting to discuss the recommendations of the EMA to ban zinc oxide therapeutic use on the 20th January, 2017. If you want to retain the therapeutic use of ZnO then you must contact your veterinary medicine regulators in your country and ask them to challenge the decision. Apparently Copa-Cogeca and other EU representative bodies should also make their positions known to the Commission.

  • David Burch

    It is a sad day, the CVMP/EMA have decided to ban zinc oxide. Their opinion will be passed o the European Commission for confirmation so one needs to lobby hard to make sure there is a suitable transition period, or it could go in 3-6 months, which would be disastrous. They could have 7.5 million piglet deaths on their hands if this goes through straight away - it is a sad situation, so we are asking for a long transition period to enable farmers and vets to prepare.

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