This month saw the release of the final report of the EIP-AGRI FG on Animal Husbandry – an EC backed initiative bringing together 20 experts from the domains of science, farming and animal health to analyse how enhancing every aspect of pig farming from biosecurity, to facilities, to welfare to feeding could help reduce antibiotic usage.
It provides an overview of current knowledge related to the use of certain feed micro-ingredients.
The publication says adding probiotics to pig diets can help to create a healthy gut, but the experts stressed their effects are diverse and need to be further explored.
Genomic-based knowledge on the composition and functions of the gut microbiota as well as its disturbances would allow the selection of more specific products, said the team.
“It seems necessary to target as much as possible the use of any potential modifier of the intestinal microbiota (probiotic, prebiotic etc) towards a specific stage of the animal (lactating piglets, weaned, etc) and towards a specific digestive problem or disease,” said the report.
David Burch, a veterinarian, animal health consultant and member of the FG, told us the members remained unconvinced of the effectiveness of probiotics and some additives in vivo.
“While there is plenty of data on their efficacy in vitro, it is debatable whether they have the desired effect in the pig’s gut. There would seem to be a lack of consistency in terms of in those results. So there is a need to build that evidence base through further investigation,” he said
Zinc oxide benefits
He said there was much greater acceptance among the experts involved of the value of zinc oxide in the post weaning diet of pigs.
The report concluded: “The use of therapeutically effective levels of zinc (2,500 ppm Zn) in the form of zinc oxide is effective in the prevention and treatment of diarrhea in young pigs; the pigs also grow faster and need less food to produce the same amount of meat. The mechanisms of action of copper and zinc in high pharmacological doses are not well understood, but they seem to modify the bacterial population in the gastro-intestinal tract.”
However the specialists note that prolonged exposure to high levels of zinc is associated with increases in some forms of antibiotic resistance in microbes, including co-selection of methicillin resistant Staphylococcus aureus (MRSA).
The publication also flags up the concerns about environmental accumulation of heavy metals. “The authorized use of zinc oxide as a feed additive does not pose a direct concern for the agricultural soil compartment. However, there is a potential environmental concern related to groundwater, drainage, and run-off of zinc to surface water.”
The experts find a reduction in Zn levels might be obtained by introduction of new, more efficient Zn compounds or forms, including Zn in complexes or as nanoparticles. “The addition of phytase to diets has reduced the binding of zinc by phytates and may allow a reduction in inclusion rate,” found the report.
The report stresses the importance of good nutrition and feed composition as best practices to enhance animal health and welfare so as to control the disease risk.
However, Burch said while there is huge political pressure to migrate away from the use of antibiotics in EU pig farming, a glut of endemic diseases in certain markets and a lack of a competitive playing field across the bloc means it is not realistic to expect a ‘one size fits all’ approach to implementation of regulation on lower antibiotic usage.
“The UK pig industry had been in the doldrums for years. We have only recently begun to feel, as a sector, that we can compete with the Danish and Dutch systems. And compared to those markets, there has been a significant lack of investment in housing and infrastructure.
Also, there needs to be streamlining of medicated feed rules given that some EU countries use medicated premixes, which are produced in the controlled, homogenous environment of the feed mill and other markets use oral powders, which often result in the pig having uncontrolled access to that medicated feed, leading to huge variances in intake in a pig.
So any EU antibiotic reduction Bill would have to take account of where each market is at,” he said.
Burch also disagrees with some aspects of EC regulatory proposals on ways to reduce antibiotic usage in livestock production. “It has been suggested that animals should not be treated with antibiotics before there are clinical signs of illness but it is extremely hard to treat an animal once it is sick. It is far easier to prevent the disease occurring in the first place.”
He said much work still needs to be done to ensure any measure to reduce antibiotics in pig production across Europe must be practical and must be applicable at farm level.
“It is feasible for corporate style farming operations, incorporating up to ten farms, to integrate antibiotic reduction drives but for individual farmers, it is much more difficult because of the loss of income for six months,” said Burch.
The report pinpoints five key areas for future research, which include:
- Exploring the causes of antibiotic prescribing habits in different countries more thoroughly.
- Developing and optimizing easy-to-use software platforms, based on smartphones, for data collection and information transfer.
- Showing the economic benefits for farmers and society of using fewer antibiotics in animals. The real effect on resistances should be linked to information on human resistance data and public health.
- Getting insight into social factors affecting the acceptance of technological innovations that would reduce the need for antibiotics on farms.
- Looking into motivations and attitudes on animal health products from different countries, to be able to propose national training schemes for veterinarians and farmers and educational measures at EU level.
The full report can be read here.
And a summary of the findings can be accessed here.