A Post-Zinc Oxide Guide to Weaned Piglet Feed Management

This is part 2 of a 3-part series. If you missed part 1, get caught up here.

The use of pharmacological levels of zinc oxide — 2,000 ppm or higher — has long been considered a practical solution to bacterial infections and diarrhea in weaned piglets. But that will soon change.

Beginning in June 2022, the use of zinc oxide at pharmacological levels will be banned across the European Union (EU). In France, the ban will take effect in January 2021. So swine producers like you will need to look for alternative methods to control bacterial infections in your herds.

Previously in this blog series, we looked at some practical management tips to help you prepare for the ban of zinc oxide. Together, we will look at some ways you can alter your feed formulations to help reduce the risk of bacterial infections. These solutions include the addition of specific enzymes, reducing the amount of protein in the diet, including inert fiber and utilizing feed acidification.

Addition of Specific Enzymes

As newly weaned piglets still have a rather small and underdeveloped digestive system, they usually benefit from the addition of enzymes to improve the digestion of nutrients. There is a large range of enzymes for specific carbohydrates, lipids and protein available. In addition, the use of phytases, often at superdosing levels (3-4 times standard recommendations), has been widely adopted in post-weaning piglet feeds. This offers the advantage of possibly further reducing zinc additions, as additional zinc is released from the binding with phytic acid, which normally can’t be digested by pigs.

Reduce Protein to Reduce Zinc Oxide

Many of the amino acids inside protein are essential nutrients for weaned piglets. Including high levels of protein in weaned piglet diets has proven to increase average daily gain but can be detrimental to gut health, particularly if the protein sources are not highly digestible. This is because any undigested protein will become food for harmful bacteria in the later part of the gastrointestinal tract and can increase the risk of infections and diarrhea, especially in the absence of pharmacological levels of zinc oxide.

Recent research published by SEGES Danish Pig Research Centre in 2019 has shown that we can reduce the risk of gastrointestinal problems in piglets by lowering the amount of protein in their diet by 3% to 4%-points. You can do this — without sacrificing growth performance — by formulating the feed with several free amino acids.

Feed proteins consist of many different amino acids, several of which are non-essential for piglet health and performance. Also, the proportions of amino acids in dietary protein do not match the proportions required by the piglet for optimal health and growth. By balancing the dietary amino acids with entirely digestible free (synthetic) amino acids, it is possible to reduce the amount of protein in the diet and limit the growth of harmful bacteria, thereby reducing the risk of infection.

Enhance Gut Development with Inert Fiber

Another way to improve gut health and reduce your reliance on pharmacological levels of zinc oxide is to formulate weaned piglet diets with inert fiber (non-digestible, insoluble and low fermentable). Such fiber helps manage gut health and to balance the microflora, keeping harmful bacteria in check.

Research conducted at Schothorst Feed Research showed that using coarse wheat bran to dilute a high-quality weaner feed reduced the risk of diarrhea to the same extent as pharmacological levels of zinc oxide. On top of that, the inclusion of wheat bran led to a higher average daily gain than the premium weaner feed used in the study. This means you can produce a more robust pig, even without the use of high levels of zinc oxide. 

Improve Digestion with Feed Acidification

Around the time of weaning, young piglets have digestive systems that are not yet fully developed, so their ability to digest feed is still limited. The optimal stomach pH for allowing pepsin — the crucial protein digesting enzymes — to work most efficiently, is between 2 and 3.5. But we know that young piglets have a limited capacity to produce enough hydrochloric acid to keep the pH level within that range.

Simply adding hydrochloric acid is not a practical option for improving digestion since it is very corrosive, difficult to manage and can damage equipment. Advancements in pig feed technology allow you to improve acidification by formulating diets with organic and inorganic acids or their salts. There are two benefits to acidification:

  1. It helps control the stomach pH, improving nutrient digestion.
  2. These acids help reduce the growth of pathogenic bacteria and lower the risk of diarrhea. This makes acidification yet another way to eliminate the need for pharmacological levels of zinc oxide in weaned piglet diets.
    Reducing the amount of limestone in the piglet feed as much as possible can also help improve acidification, as limestone buffers the piglet’s stomach pH. You can do this by replacing limestone with calcium-based organic acids.

Protein also has a tremendous acid buffering capacity. Reducing the amount of protein in the diet, as I mentioned previously, is another way to improve acidification.

Prepare for the Ban: Weaned Piglet Feed Formulation and Performance Trace Minerals

Zinc oxide at pharmacological levels has long been a simple and cost-efficient solution for swine producers to reduce the prevalence of bacterial infections and diarrhea in their weaned piglets. With the ban set to take place in 2022, you will need to look for new ways to formulate your piglet diets to solve these problems. Two such ways include reducing protein by utilizing free amino acids and by adding inert fiber in the diets.

Another tactic, which will cover in Part 3, is to include Zinpro Performance Minerals® in your swine nutrition program. Since Availa®Zn is more digestible than zinc oxide, it has been proven to strengthen tight junctions and boost intestinal integrity when supplemented in piglet nutrition programs. This will allow you to reduce diarrhea even though you are feeding much lower levels of zinc.

Our industry continues to be challenged with the loss of technologies that have helped us improve pork production in the past. Our expertise and commitment will continue to drive us to find innovative ways to meet any new regulations and continue producing responsibly raised pork.

To discuss the potential impacts of a zinc oxide ban in your region, reach out to your Zinpro representative and start the conversation today.

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