Prevention of post weaning diarrhea (PWD) of piglets without amending the feeds with medical doses of zinc oxide (ZnO) was the topic of ZeroZincSummit2022, held in Copenhagen, Denmark, on 22 – 23 June. The summit, organized by the Danish Pig Research Centre SEGES and Danish Veterinary and Food Administration, was very timely, as the ban on high doses of ZnO in piglet diets became effective from June 26 onwards within the EU. Despite several years of preparation for this change, the general view seems to be that open questions on feeding and management of piglets without medical ZnO still remain, and more research needs to be done in this field. 

ZeroZincSummit offered a generous package of information on management tools, feeding strategies, optimal nutrient composition, and feed additives for the pig industry. The total of 7 keynote lectures, 18 short oral presentations, and 84 posters also covered immunity and gut health, prevention and treatment of PWD, and practical experiences from farms which have already abandoned the use of medical ZnO in piglet feeds. Of course, the event of 450 participants was a great opportunity for networking and meeting colleagues, fellow scientists, and industry members after the long period of Covid-restrictions.

The event was opened by Christian Fink Hansen, Director at SEGES Danish Pig Research Centre, and Nikolaj Veje, Executive Director of the Danish Veterinary and Food Administration

Although PWD by definition happens in the post-weaning period, many of the presentations highlighted the importance of the pre-weaning phase for the health and performance of post-weanling piglets. Large litter size, low birth weight, insufficient colostrum intake, and immature digestive system are a combination which makes piglets susceptible to a variety of health problems and poor performance.

As pointed out by Mick Bailey, professor of Comparative immunology from the University of Bristol, UK, the immune system of neonate piglets is not fully competent in distinguishing harmless diet-derived proteins from potential pathogens, which leads into unnecessary inflammations in the intestine. Dietary changes during weaning initiate large changes in the intestinal microbiota, and at that time the maternal immunoglobulins are not any more present to help the piglet out of the stressful situation. If pathogens are present in the environment, the risk of PWD becomes even more prominent.

The keynote lectures and oral presentations raised several potential dietary solutions for improving the situation, such as optimizing the fiber and amino acid composition of the feed, and modulation of the intestinal microbiota and supporting the immune system by pro- or prebiotics or other feed additives. Balanced intestinal microbiota of sows and piglets, and the adequate availability of colostrum for all piglets are important factors which can be improved by dietary means.

For successful weaning, management is as important as feeding. Several presentations highlighted the importance of hygiene and climate control, as well as monitoring and stimulating the piglets. Washing, drying, disinfecting and warming up the pens for the newly-weaned piglets reduces the risk of PWD. Giving small extra portions of porridge or electrolyte solution for the piglets several times a day during the first days ensures that the piglets stay active and that they all quickly learn the location of feeders. By combining dietary modulation with good management practices, it is fully possible to stop using medical doses of ZnO without the need to increase the usage of antibiotics, and without seeing losses in production parameters.   

Hankkija has developed two unique products with proven capacity to help the piglets through weaning: the resin acid -based Progres® and yeast hydrolysate Progut®. Swine Nutrition Researcher Anouschka Middelkoop from Schothorst Feed Research presented a poster titled “Effect of dietary resin acids and hydrolysed yeast in piglets challenged with F4+ enterotoxigenic Escherichia coli“, which describes the positive effects of Progres® and Progut® in a controlled E. coli challenge study. Both products, in combination and alone, made the weaned piglets more resilient to enterotoxigenic F4-positive E. coli in this study.

R&D Manager Hannele Kettunen from Hankkija gave a short oral presentation which summarized the three main studies proving the benefits of Progres® for sows and pre- and post-weanling piglets. The presentation titled “Dietary resin acids improved performance of sows and piglets and acted as an immune modulator for piglets” proved that Progres®-amendment to sow and piglet diets acts as performance enhancer, balances the intestinal microbiota, and modulates the systemic immunity of piglets in a similar way as medical doses of Zn.   

In a poster titled “Raising weanling piglets without medical doses of zinc: an example from Finland”, Dr. Kettunen presented the dietary and management strategies of a Finnish farm (Heikkilä farm, Rusko, Finland) which successfully abandoned the use of high doses of zinc in piglet diets already in January 2016. Both Progut® and Progres® are being routinely used in piglet diets this farm.