Zinc oxide is to be phased out of pig diets by 2022 under new EU rules. We spoke to one UK producer to find out how he is already managing without it to see what others can learn.
Pig producer Simon Watchorn has successfully removed zinc from rations after working with his vet and adopting rigorous biosecurity, hygiene and nutrition measures.
Mr Watchorn runs a 650-sow outdoor breeding-to-finishing unit on his 400ha Park Farm near Bungay, Suffolk.
The decision to remove zinc from diets was taken 12 months ago and followed a successful programme to end routine antibiotic use on the farm.
Mr Watchorn wanted to stop using antibiotics because of the publicised concerns over resistance and because the regular use in rations was costing £15,000 a year.
The target was to cut out zinc as well, but he and his vet felt that removing both elements at the same time carried too great a risk.
Instead, they decided to cut antibiotics first and devised a plan to bolster the pigs’ immune systems by cutting down the disease challenge.
“We introduced an acidification process to the water supply to reduce the presence of harmful bacteria,” Mr Watchorn explains.
Lowering the water to a pH of 3.8 kills the salmonella bacteria and, at a total annual cost of about £5,600, acidifying the water saved £10,000 a year compared with the previous antibiotic treatment cost.
Cleaning and biosecurity programme
The acidification process went hand in hand with a rigorously applied cleaning and biosecurity programme, which included:
- All huts de-greased, cleaned, then disinfected and left for the active ingredient to penetrate the structure between batches
- Disinfectants with different active ingredients used to widen scope of control
- All overalls washed daily
- Boots cleaned and disinfected between sites
- Separate personnel used for the breeding site
- Weaner site always moved to fresh ground
- Insulation in arks increased to keep pigs warm to help fight off infection
“Only once the policy was in place and working did the vet and I agree to take out zinc,” Mr Watchorn says.
“We were extremely nervous about removing zinc because it has been vital in reducing scours in piglets at weaning,” he adds.
The first few months in the high-health environment passed with little difficulty.
But the winter showed how important it was to have every element of the stringent programme working perfectly.
Plummeting temperatures froze pipes, which meant the acidified water could not be pumped to troughs.
“Instead, we tankered water out to the fields. But it didn’t have the added acid and so was a higher pH. Within days weaned piglets began to scour,” Mr Watchorn says.
“If we had still been feeding zinc the vet and I felt we would not have seen the scours return.
“The setback showed us how vulnerable piglets are without the zinc and how you have to be on top of every element of cutting the disease risk when it is not in the ration anymore,” he says.
Once the acidified water supply returned, the scours ended.
“After 12 months I am more confident, but I would warn anyone that removing zinc cannot be done without a great deal of planning, a ruthless approach to hygiene and biosecurity and a working partnership with a vet,” he says.
What is zinc oxide and why is it important?
Zinc oxide has been added to piglet feed since the early 1990s and is included in up to 90% of starter diets.
Its inclusion is to help piglets fend off infections and reduce diarrhoea when their immune systems are lowered during and immediately after weaning.
Research has indicated that zinc oxide has an antibacterial effect against bacteria like E coli, Staph aureus and Enterococcus species. But certain EU countries have raised concern that zinc is contaminating soil. In June the European Commission announced proposals for a programme to phase out the use of zinc oxide in pig feed on environmental grounds by 2022.
AHDB tips and advice
It is essential that pigs at the point of weaning are in the best condition possible that will allow them to thrive in the post-weaned period, writes Dr Mandy Nevel, veterinary senior manager at the AHDB.
- The changes that the young pig experiences at weaning are stressful and anything that can be done to reduce the impact of these will help
- Some of these changes are obvious and difficult to modify. For example, the dietary change from mother’s milk to pellets and moving to different accommodation with mixing and possibly transport to a new site.
- Others may be less obvious but are very important and may be easier to control, such as the temperature of the new accommodation
- New accommodation should be similar to that from which the pig has come – ensure the receiving pen is heated before the pigs are put in rather than putting the pigs into a cold room and waiting for it to heat up
- With the changes in diet, the pig’s stomach will be changing both in acidity and in microflora (important for the pig’s immunity)
- Use of antibiotics at this stage can disrupt this process and actually lead to digestive problems in the post-weaned period
- Good stockmanship is paramount
- Robust pigs (each and every pig, not just the group) should be a minimum of 6kg and as close to 28 days of age as possible (this means tight farrowing and service periods)
- Pigs should be healthy with no signs of physical (lameness) or infectious disease (scour)
- The receiving pens should be clean, dry and disinfected
- Avoid thermal stress; ensure the new building temperature closely matches the farrowing house and that draughts are excluded
- Consider carefully the group size. Is it suitable for the facilities available? Avoid mixing and moving where possible.
- Consider the sex and size (and importantly the range of sizes) of pigs you group together. Handle pigs gently.
- Do all you can to ensure feed intake is maximised. Fresh, palatable, highly digestible food of uniform grist size, which can be eaten without excess competition as often as desired, is essential. Remember pigs before weaning have been having lots of small meals on their mother – trying to recreate this will pay dividends.
- Pigs need to have clear day and night (dark) periods. In the first few days after weaning consideration should be given to the length of the dark as pigs will be unlikely to find food in the dark.
- Ensure feed and water is clean and fresh. Weaning food has a high milk content and can become rancid quickly in the warmth of a weaning pen.
- Ensure pigs are able to find the clean, fresh water quickly and water drinkers are suitable for the size of pig
- Establish an appropriate vaccination programme
- Prompt action should be taken to help sick pigs or those failing to thrive