Effect of herbal extracts on piglet performance and small intestinal epithelial villi

The effect of a mixture of herbal extracts on piglet performance was estimated on 178 piglets allocated to 3 groups comprising 6 litters each. Group I (control) was fed with the standard barley-wheatsoybean mixture. Group II received the same mixture supplemented with a blend of formic and propionic acids. Group III received the basal diet supplemented with a mixture of water extracts from sage, lemon balm, nettle and coneflower (20, 30, 30, and 20%, respectively) at 500 mg/kg feed. The experiment lasted for 84 days but on day 56 six piglets from each group were slaughtered and their gastrointestinal tract was removed. Apparent digestibility was estimated using the Cr2O3 indicator method. Acidity of digesta was measured in the stomach, ileum, and caecum, and volatile fatty acid content was evaluated in the ileum and caecum. Amounts of bacteria and morphological structure were evaluated in the ileal digesta and epithelium, respectively. In the experimental groups less dead and culled piglets were observed than in the control group. Piglets in the herb-supplemented group grew faster than control animals and showed significantly higher final average body weights. There was no significant difference in feed utilization. Acetic acid content was higher in both groups receiving supplements. The amount of propionic acid in the caecum of animals from the herb-supplemented group was lower than in animals from groups I and II. There were no significant differences in bacteria population in ileum chyme. The herbal extract improved the structure of the ileal epithelium by significantly increasing villus height. Better digestibility of nutrients could be due to higher villi in this group.