'No silver bullet' has been one of the most commonly used phrases in the pig industry when the topic of therapeutic zinc oxide removal is deliberated.
"Trialling zinc oxide removal has been, and continues to be a very long, drawn out process," said Dr Marian Scott, innovation and development manager at Devenish.
"We have to ensure that the animals are fed zinc-free for an extended period of time to ensure that the challenge on farm reflects the exact position when zinc is completely absent. Only then will the conditions required for an appropriate trial be reached.
"We have found that on some units, the negative control, the standard diet without therapeutic levels of zinc, can be the best performing treatment in the first batch of piglets trialled."
There are two main reasons for this, Dr Scott explained. The palatability of the feed improves when zinc is removed and the first batch is not truly challenged as the previous batch of pigs has received zinc - hence the environment may not be as 'pig sick' as it will be after a few batches zinc free.
"If we rely on a single trial we could be lulled into a false sense of security. I would be confident that we all have been seduced at one time or another with a product that has claimed to be a replacement for zinc," Dr Scott added.
"They are accompanied by very impressive trial results and, when they are first implemented, a good initial result often ensues. But when they are continued for a period of time, the performance of the weaned pigs often deteriorates significantly!"
This experience has driven Devenish and A-One Feeds, part of the Devenish Group specialising in starter feeds, to focus their research resources and facilities over recent years on identifying solutions to zinc removal.
They have undertaken a number of research projects in association with universities and research institutes around the world and have unearthed 'some very exciting findings'.
"Our results indicate that when our research innovations are implemented in our diets, not only is zinc removal possible, but they reveal a trend in performance improvement," said Dr Scott.
The low levels of immunity and high levels of stress in piglets at weaning leads to several physical changes in the gut, which increases the likelihood of disease and enteric issues.
Efficient reduction of these physiological changes post weaning can drive performance. Studying the exact effect and minimising the onset of the physical changes using specifically developed feed ingredients have allowed the company to improve the performance of its diets.
The most recent trial result from one of Devenish's trial sites that has had zinc removed for more than three months has revealed that zinc-free formulations improve performance in comparison to both positive and negative controls.
"This demonstrates clearly for me that our innovative feed ingredients and formulations have the potential to alleviate a number of issues that will arise due to zinc removal and, alongside good hygiene and good management, will be key in allowing our producers to cope without zinc," Dr Scott said.
