Effects of hydrolyzed yeast on weanling pig growth performance, fecal dry matter, and stress-related blood antioxidant criteria

Lay Summary Feed-grade medications have been widely used in swine production due to their ability to treat a diagnosed pathogen challenge, regulate gut microbiota, promote growth, enhance feed efficiency, and reduce inflammation. Due to concerns of bacterial resistance, some feed-grade medications have been restricted as a growth promotor in some countries. The limitations on feed-grade medications have increased interest in alternatives, particularly Saccharomyces cerevisiae yeast-based products. In this study, adding a hydrolyzed yeast-based product (Saccharomyces cerevisiae) to nursery pig diets helped lower levels of inflammation-related compounds in the blood. Feeding 0.04% hydrolyzed yeast without carbadox led to a small improvement in feed efficiency compared to using carbadox alone but could not fully replace carbadox to recover growth performance. Additionally, increasing inclusions of hydrolyzed yeast improved fecal dry matter in the early nursery.