Evaluation of a Phytogenic Blend on Inflammation, Oxidative Stress, Gut Permeability, Gut Morphology, and Performance in Nursery Pigs

Two experiments were conducted to determine the effects of a phytogenic feed additive (PFA) on growth performance (exp. 1) and inflammation, oxidative stress, gut permeability, and gut morphology (exp. 2) in nursery pigs. Dietary treatments were, 1) basal diet [CON] and 2) basal + 0.015% PFA (Digestarom^®, Biomin Holding GmbH). In exp. 1, pigs (n=315/trt, BW=5.79± 0.13 kg) were allotted 21 pigs/pen for a total of 30 pens and pens were assigned within weight blocks to the dietary treatments. Pigs were fed ad libitum and pen BW and feed disappearance were measured on d 19, 30, and 48. During exp. 1 pigs experienced a porcine reproductive and respiratory syndrome virus outbreak. In exp. 2, pigs (n=11/trt, BW=7.50 ± 1.04 kg) were penned individually and fed the dietary treatments. On d 26, blood samples were collected from each pig, then pigs were orally gavaged with a solution of lactulose and mannitol, urine samples were collected for a period of 12 h after gavage. On d 28, pigs were euthanized and samples from the liver and ileum were collected. In exp.1, for the 48-d period, supplementation of PFA did not significantly affect (CON vs. PFA, P≥0.362) BW (16.90 vs. 17.10 kg), ADG (0.345 vs. 0.351 kg/d), ADFI (0.503 vs. 0.504 kg/d), or pig losses (4.44 vs. 3.18%), but tended to increase Gain:Feed (0.687 vs. 0.696 kg/kg, P=0.066). In exp. 2, supplementation of PFA increased serum IGF-1 (124.91 vs. 144.90 ng/mL, P=0.002) and tended to reduce serum interferon (IFN)-α (1.12 vs. 0.62 pg/mL, P=0.084); no significant effects (P≥0.194) were observed on serum haptoglobin, IFN-γ, interleukin (IL)-6, IL-1β, IL-10, IL-8, and tumor necrosis factor-α. Supplementation of PFA did not significantly affect (P≥0.434) markers of oxidative stress in the liver and ileum (malondialdehyde, protein carbonyls, glutathione peroxidase activity, and superoxide dismutase activity) and in-vivo gut permeability (lactulose:mannitol ratio). Supplementation of PFA significantly increased (P<0.001) villi height (263 vs. 302 µm) and crypt depth (180 vs. 206 µm), but did not affect villi:crypt ratio (1.38 vs. 1.40, P=0.758). Supplementation of PFA significantly increased goblet cell number/villi (13.6 vs. 16. 4, P=0.023). Supplementation of PFA reduced pro-inflammatory cytokine expression, improved gut morphology, and increased goblet cell count. Overall, supplementation of PFA was able to improve feed efficiency and numerically reduce pig losses during a naturally occurring health challenge.