Enhancing growth and gut health in nursery piglets: effects of enzymatically treated yeast and zinc oxide

Abrupt weaning in pigs triggers nutritional, environmental, and psychological stress, often resulting in decreased feed intake, poor weight gain, and sometimes diarrhea, morbidity, and mortality. Traditionally, pharmacological levels of trace elements like zinc oxide (ZnO), and specialized feed additives have been used to manage these post-weaning challenges. However, due to rising antimicrobial resistance, many regions have banned or are considering banning antimicrobial growth promoters. Finding alternative nutritional strategies for newly weaned pigs is increasingly important. Yeast derivatives have emerged as potential alternatives, but comparative efficacy with pharmacological ZnO remains underexplored. This study investigated the effects of enzymatically treated yeast (ETY) and pharmacological zinc oxide on growth performance, nutrient digestibility, and gut health in nursery piglets.

Methods: A total of 144 piglets (21 days old) were assigned to one of four dietary treatments: control diet; control + ETY; control + ZnO; and control + ETY + ZnO. The piglets were housed in 36 pens with 4 piglets per pen and were fed the diets for 42 days. Body weight and feed disappearance were recorded weekly. One pig per pen was killed for organ weights, blood, and tissue samples on day 14 post-weaning.

Results: Piglets fed diets with ETY or ZnO, or both, had higher final body weights compared to those on the control diet. During the second phase, the ETY + ZnO group showed increased feed intake. Digestibility of dry matter and energy was improved in piglets receiving ETY or ZnO. The combination of ETY and ZnO resulted in lower levels of harmful E. coli and better balance of beneficial gut bacteria. ZnO diets also enhanced nutrient absorption and zinc excretion. ETY improved intestinal villi height and overall gut health, while the ETY + ZnO group had higher plasma immunoglobulin A (IgA) levels, indicating better immune function.

Conclusion: Both ETY and ZnO positively influenced piglet growth and gut health, with ETY also improving intestinal function and immunity.

Christensen, B., Zhu, C., Mohammadigheisar, M., Schulze, H., Huber, L. A., & Kiarie, E. G. (2022). Growth performance, immune status, gastrointestinal tract ecology, and function in nursery pigs fed enzymatically treated yeast without or with pharmacological levels of zinc. Journal of animal science, 100(4), skac094. https://doi.org/10.1093/jas/skac094