Enhancing Weaned Pig Health and Performance with Zinc and Iron

Weaning is a critical and stressful period for piglets, making them vulnerable to pathogens. Targeted zinc and iron nutrition during this phase can significantly improve health outcomes and growth performance.

Zinc (Zn) is vital for weaned piglets. It maintains a tight intestinal barrier, preventing toxins and pathogens from crossing into tissue and triggering inflammation. When pathogens do enter, a fast immune response is essential – this depends on rapid immune cell replication, which requires zinc.

Zinc can be added to diets in inorganic or organic (chelated) forms. Not all sources are equal: Zinpro^® Performance Minerals^®, bound to single amino acids, use amino acid transporters for unique absorption. This pathway avoids stomach degradation, making more zinc available to the animal.

In a study, 7-week-old piglets challenged with Lawsonia intracellularis (ileitis) recovered faster when part of the inorganic zinc in the diet was replaced with Zinpro^® Availa^® Zn. (Figure 1). These piglets showed:

• Less intestinal damage

• More immune cells

• More pigs with antibodies

This shows that Zinpro Availa Zn improves gut integrity and speeds up recovery from ileitis.

Iron (Fe) is essential for oxygen transport, energy metabolism, and immune function. While preventing anaemia in suckling and weaned piglets is a primary concern, iron also plays a critical role in gut health. In the intestine, both the host and microbes – including pathogens – compete for iron. Excess iron can fuel pathogen growth and act as a pro-oxidant, increasing oxidative stress and inflammation, which weakens the gut barrier.

Weaner diets contain at least 100–200 ppm of background iron from ingredients like soybean meal, wheat bran, phosphate and limestone. Adding phytase releases part of this iron, making it available to both pigs and microbes. On top of this, 100–150 ppm of supplemental iron is commonly added, bringing total levels to 200–350 ppm. Yet, newly weaned pigs absorb iron originating from feedstuffs or inorganic supplemental sources poorly.

To reduce oxidative stress, a non-oxidizing, highly metabolically available source like Zinpro^® ProPath^® Fe – bound to single amino acids – can be used. This allows for a lower level of supplemental iron in the diet while still meeting the pig’s iron needs.

A study at Iowa State University showed that piglets fed 100 or 50 ppm of Zinpro Fe had lower mortality than those fed 100 ppm of iron as FeSO₄. However, 25 ppm of Zinpro Fe alone was insufficient, indicating that while Zinpro Fe is effective, too low a dose compromises survival. (Figure 2)

A Danish study compared two post-weaning supplementation strategies in 757 piglets (avg. 6.6 kg). One group received the farm’s standard diet (Control), while the other (Zinpro ZnFe) had 50 ppm zinc and 90–45 ppm iron from inorganic sources replaced with  Zn and Fe from Zinpro Performance Minerals from day 1–28. Total supplemental iron ranged from 190 to 220 ppm in the Control diet and was 140 ppm in the Zinpro ZnFe diet. From day 29–42, only Zinpro Zn was continued.

Health status was good overall, with no difference in diarrhoea or medication days. However, mortality was halved in the Zinpro ZnFe group (0.8% vs. 1.6%), supporting earlier findings on the Zinpro Fe health benefits.

Most notably, piglets fed Zinpro ZnFe grew faster—569 g vs. 541 g average daily gain, resulting in 1.1 kg more body weight by day 42 (see Figure 3).

Using metabolic available forms of zinc and iron can reinforce gut integrity, reduce oxidative stress, and enhance immune function. These improvements translate into better health, faster growth, and improved economic returns for swine producers.

For more information, please contact Tim Horne: thorne@zinpro.com or visit https://www.zinpro.com/species/swine/nursery/

Your animals deserve the best and taking the proven path to mineral nutrition is a crucial step. Watch this video to learn how only Zinpro Performance Minerals use a unique pathway for absorption – the amino acid transporter. https://www.youtube.com/watch?v=xZW9kwOqDEU&t=13s