Polyphenol-rich plant products are widely used as feed additives for their anti-inflammatory, antioxidant, and antimicrobial properties. The aim of this research is to test the hypothesis that feeding grape pomace (GP) to fattening pigs modulates the intestinal immune and antioxidant response, promotes the morphostructure of the small intestine, and improves growth performance. Fifty Piétrain fattening pigs were randomly divided into five groups, each consisting of 10 pigs. The groups were fed a basal diet with no supplementation (control) or a diet supplemented with 1 gGP/kg (E1), 5 gGP/kg (E2), 10 gGP/kg (E3), or 15 gGP/kg (E4). The doses were selected based on preliminary tests. The pigs were slaughtered after 90 days, and their duodenum, jejunum, ileum, and caecum were sampled. We recommend a dose of 10 gGP/kg because it leads to many beneficial effects, including a significantly increased villous height, intestinal crypt depth, and V/C ratio in the duodenum and jejunum (p < 0.05). It also decreased the expression of pro-inflammatory markers such as IL-1β in the ileum and caecum, TNF-α in multiple intestinal segments, and MHC-II in the duodenum, jejunum, and caecum. Additionally, antioxidant activity was promoted through the increased immunohistochemical expression of Nrf2 and reduced NF-kB p65 expression. Growth performance also improved, with significantly higher ADG (p = 0.01) and ADFI values (p < 0.01) than those in the control group. In conclusion, polyphenol-rich grape pomace can be used as a supplement in fattening pig diets to maintain their health and productive performance.

Supplementation of feed with turmeric (Curcuma longa) has been shown to be beneficial in poultry farming. The present study aimed at evaluating the effect of turmeric on the duodenal structure of broiler chickens during the first 42 days of life. A control and three treatment groups (turmeric powder added to feed at the following doses: E1 - 5; E2 - 10; E3 - 20 g/kg feed) were constituted (n = 8). Addition of turmeric powder in the feed resulted in an increase in intestinal villi height and a decrease in crypts depth in case of groups E1 and E2, while the villus height to crypt depth ratio generally did not differ significantly from the control. Turmeric also influenced the histological structure of the duodenum, as well as the presence of IL-6 and TNFα, as evidenced through staining. Addition of 0.5 and 1 % turmeric powder in the feed had evident results on body weight gain.