Since the EU’s 2022 regulations heavily reducing the use of zinc oxide (ZnO) in animal agriculture, pig producers across Europe have had to adjust care for post-weaned swine, turning to alternative products and practices to keep their animals healthy.
Animal nutrition plays a key role in a holistic approach to addressing this issue, with a range of different additives available to try to mitigate the challenges the reduction in ZnO has brought.
Feedinfo delved deep into this issue with NOVUS’ Dr. Roberto Barea, Technical Service Manager for Swine, South Europe, to discuss the scale of the ban and how we have seen it affect the industry, additives being utilised to support swine producers since this development and what other sustainability-linked legislation we might see introduced next.
[Feedinfo] Can you start by giving a little history about the EU ZnO ban? How did it come about, and who is most deeply affected by it?
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[Roberto Barea] In March 2017, the European Medicines Agency (EMA) completed a report on the safety and effectiveness of veterinary medicine products containing ZnO that are administered orally to livestock. The report concluded the overall benefit-risk balance of using pharmacological levels of ZnO for pigs was negative, as the benefits of preventing diarrhea did not compensate the risks of adding zinc to the environment. It also asserted ZnO might increase the prevalence of antibiotic resistant bacteria, but the risk was not quantifiable in that report. |
Dr. Roberto Barea |
Following the EMA’s report, the European Commission issued a decision in June 2017 that member states accepted: five years to withdraw authorizations of veterinary medicine products containing ZnO. As of June 2022, medicinal doses of ZnO are no longer permitted in the EU (the maximum level admitted in piglets is 150 ppm of zinc in complete feed). It is acceptable to use ZnO as a feed additive so long as the final feed does not exceed the allowed limits for dietary zinc.
As such, the European pork industry has had to redesign post-weaning diets and management, following holistic approaches to address comprehensively animal nutrition, health, farm biosecurity and even animal welfare, in an effort to support piglets without nearly as much ZnO as the industry had come to rely on.
[Feedinfo] We know trace minerals support animal health and performance, but why has ZnO in particular become so widely used in the piglet stage of development?
[Roberto Barea] During the last decade of the 20th century, studies found that including 2,000 to 3,000 ppm of ZnO in the diet during the two weeks post-weaning reduced diarrhea occurrence, ultimately supporting piglet growth. However, despite hundreds of articles being published, the actual mechanism of action of pharmacological levels of ZnO is not fully understood. The beneficial effects of ZnO may be related to a substantial improvement in nutrient absorption and intestinal morphology rather than simply providing the zinc nutritional requirement to pigs. On the other hand, ZnO is shown to reduce bacterial adhesion to mucosa cells, supporting overall health and performance. Considering the reduction of diarrhea in piglets supplemented with high dietary levels of ZnO, we can expect a different mode of action between ZnO and traditional antimicrobials like antibiotics.
[Feedinfo] What have you and your colleagues seen in the field since 2022?
[Roberto Barea] We have seen production managers working more closely with nutritionists to help alleviate the instances of diarrhea they are seeing in piglets. Without corrective measures, we witness an increase in diarrhea and in the use of antibiotics in post-weaned piglets when ZnO is eliminated. The removal of ZnO is further complicated by the ongoing pressure to reduce antibiotic use in animal production and restrictions in the prophylactic use of antibiotics. The swine industry in Europe continues to evaluate alternatives to ZnO in a holistic manner, combining several strategies and tools from the nutrition sector while strengthening animal health, animal welfare and biosecurity.
[Feedinfo] What are producers and nutritionists doing from a management or feeding program perspective to combat post-weaning health challenges?
[Roberto Barea] The main objective of a piglet nutrition program is to avoid post-weaning growth depression while helping piglets to adapt to a grain-based diet. It is important to make this transition as rapidly as possible. Where feeding is concerned, there are two things producers can do. First, increase feed intake during the first week post-weaning to promote growth and overall health during the weaning phase as well as optimise performance throughout the whole pig's production cycle. Second, phase feeding can help facilitate the transition from one feed to another in the piglet’s gastrointestinal tract. This feeding management will not only help cover the piglet’s nutritional and energy requirements at each physiological phase of its growth, but it could also help support its immune system and intestinal health.
In addition, some nutritional interventions during this critical period should include: 1) supplementation of highly digestible and palatable ingredients; 2) coarse particle size of the ingredients and low buffering capacity of the feed to improve the functionality of the stomach and intestine (through proper use of certain raw materials, minerals and organic acids); 3) a low proportion of fermentable and inert fiber; and 4) low crude protein content in the diet to reduce the risk of protein fermentation and gut microbiota dysbiosis.
[Feedinfo] What additives are producers and nutritionists using to support the industry through the withdrawal of pharmaceutical ZnO from the market?
[Roberto Barea] From a nutritional point of view, feed additives (prebiotics and probiotics, organic acids, trace minerals, etc.) are tools that can be used as part of these nutritional strategies, but clearly they cannot be used as a “silver bullet” to replace ZnO.
Organic acids are one of the most commonly used groups of feed ingredients in swine nutrition. In addition to their effective control of pathogens in the feed, due to their acidic nature, they can efficiently reduce the gastric pH in weaned piglets, counteracting the buffering capacity of the diet and ensuring adequate digestion of protein. The factor that limits the antibacterial efficacy of organic acids in the gut is the need to be released at longer parts of the intestine. Protecting the organic acids in a lipid matrix can ensure their release in more distal parts of the gastrointestinal tract, helping to positively modulate the gut microflora.
In a project led by NOVUS in collaboration with the Complutense University of Madrid and the University of Bologna, we used metagenomic sequencing, which analyses a sample’s total DNA to identify the presence of micro-organisms and their genomic content, in this case providing details about gut bacteria composition. We found dietary supplementation of a protected benzoic acid in a lipid matrix (PROVENIA™ Feed Solution) during post-weaning positively influenced the piglets’ fecal microbial profile compared to pharmacological doses of ZnO, as shown by an increase in alpha diversity (the measurement of a species’ richness in an ecosystem), which is considered a positive parameter of the intestinal microflora’s modulation. The study also found a proliferation of certain bacteria like Ruminococcus, Prevotella and Fibrobacter that are involved in dietary polysaccharide fermentation and the endogenous production of short-chain fatty acids (such as butyric acid), which are known to be beneficial to the gut, supporting intestinal integrity and offering antimicrobial properties. Definitely, piglets supplemented with PROVENIA™ Feed Solution saw reduced medication costs and improved performance growth parameters, modifying in a positive manner the intestinal microbial profile and the alpha diversity, as seen below.
Figure 1: Effects of PROVENIA™ Feed Solution vs. ZnO on alpha diversity measurements
Figure 2: Improvement on production parameters of PROVENIA™ Feed Solution vs. ZnO
Swine producers in Europe were using PROVENIA™ Feed Solution for many years before the ban of ZnO at pharmaceutical levels as they saw this protected organic acid as a good tool for supporting the growth performance and intestinal health of post-weaned piglets in combination with other nutritional and management strategies.
[Feedinfo] Are there other regulations on the horizon that the swine industry should be concerned about or be preparing for?
[Roberto Barea] In 2022, overall production of pig meat in the EU reached 23 million tons, making it the world's second largest pork producer after China and the biggest exporter of pork and pork products. However, production in the EU is expected to decline in the coming years due to a number of challenges including the high cost of complying with future EU farm management requirements, animal welfare and environmental sustainability regulations concerning water and air pollution. The EU recognizes there is an urgent need to reduce the dependence on agro-chemicals (reducing over-fertilization and pesticide use) and antimicrobials, to increase organic farming, improve animal welfare and reverse biodiversity loss. For example, the European Commission has taken measures to reduce total sales of antimicrobials for farm animals in the EU by 50% by 2030.
The EU pork sector is regulated by legislative acts relevant to food safety, public and animal health, environmental protection and animal welfare throughout the production process. All of these topics are of global interest, so we can expect other regions and countries to take similar paths to those taken by EU members.
[Feedinfo] To what extent is swine gut health a priority for NOVUS’ research and development teams? What kinds of developments should the market be expecting from you in the coming year in this space?
[Roberto Barea] Finding innovative ways to support pigs at weaning and beyond requires combining several of the strategies and tools discussed above to complement the different modes of action and targets synergistically. At NOVUS we are actively defining a holistic approach using MINTREX® Bis-Chelated Trace Minerals and PROVENIA™ Feed Solution in post-weaning piglets. We are studying the effect of this combination on piglet growth performance and intestinal microbial profile, among other parameters.
As part of a doctoral study in collaboration with the University of Belgrade (Serbia) supplementation of MINTREX® Zn, Cu and Mn, and PROVENIA™ Feed Solution were shown to significantly improve piglet growth performance, along with the integrity of the mucosa in different sections of the intestinal tract (measured as the villus-height-to-crypt-depth ratio), as well as demonstrating a positive impact on the composition of the intestinal microbiota, stimulating the growth of favorable bacteria at the expense of potential pathogens such as E. coli. We are continuing to study this combination in similar conditions in other experiments and hope to share those findings in the coming months.
Piglet post-weaning challenges are an ongoing concern for the industry. What we’re learning through research at NOVUS, together with our understanding of animal welfare, biosecurity measures and innovative nutritional strategies, is allowing us to create holistic approaches for pork producers in the EU and beyond.
Published in association with Novus International, Inc.
