Effects of plant essential oil supplementation on growth performance, immune function and antioxidant activities in weaned pigs

Background: The aim of this study was to determine the effects of plant essential oil supplementation on growth performance, immune function and antioxidant activities in weaned pigs. Methods: In the study, 24 weaned pigs were used to explore the effects of plant essential oil (PEO) on growth performance, immune properties and antioxidant activities. Pigs were fed with a basal diet (CON) or basal diet containing different concentrations of PEO (PEO50: 50 ppm; PEO100: 100 ppm; PEO200: 200 ppm). After 3 weeks, all pigs were slaughtered and blood and tissue samples were collected for biochemical analysis. Results: The results showed that PEO supplementation quadratically increased body weight gain (BWG) (P = 0.031), linearly (P < 0.05) and quadratically (P < 0.05) decreased F:G. In addition, IgG increased linearly (P < 0.05) and IgM increased linearly (P < 0.05) and quadratically (P < 0.05) as PEO supplementation. Similarly, MDA in serum, jejunal mucosa and pancreas were linearly decreased (P < 0.05) and GSH in serum (linear and quadratic, P < 0.05), duodenal mucosa (linear and quadratic, P < 0.05) and in ileal mucosa (linear and quadratic, P < 0.05) were notably increased. Futhermore, antioxidant-related genes expression levels of GST in spleen (linear and quadratic, P < 0.05), GPX1 (quadratic, P < 0.05) and SOD1 (linear, P < 0.05) in spleen and GST in liver (quadratic, P < 0.05) were markedly upregulated by PEO supplementation increasing. Conclusions: These results suggest that PEO improves growth performance, immune function, and antioxidant activities in weaned pigs, and it may also relieve weaning stress if used as a feed additive in the livestock industry. And that supplementation 200 ppm PEO in diet would seem to be economically feasible.