Impact of Dietary Inclusion with Cocrystal Essential Oil on Growth Performance, Nutrient Digestibility, Intestinal Morphology, and Antioxidant Status in Weaned Piglets

This study assessed the impact of cocrystal essential oil (CEO) inclusion on growth performance, nutrient digestibility, intestinal morphology, and antioxidant status in weaned piglets. Ninety-six weaned piglets were assigned to four groups (n = 8, three piglets per pen). The piglets in the four groups were fed basal diets added with 0, 120, 180, or 240 mg/kg of CEO, respectively, over a 28-day trial period. Results showed that during weeks 1–2, piglets in the 240 mg/kg CEO group exhibited a lower diarrhea rate and diarrhea index compared to the control group (p < 0.05). In weeks 3–4, the 180 and 240 mg/kg CEO groups demonstrated a reduced diarrhea rate and diarrhea index compared to the control group (p < 0.05). Relative to the control group, the apparent total tract digestibility (ATTD) of dry matter was elevated in piglets fed diets added with 120, 180, or 240 mg/kg CEO at both day 14 and day 28 (p < 0.05). Additionally, the ATTD of crude protein was elevated in the 120 mg/kg CEO group at day 14 and in the 180 mg/kg CEO group at day 28 (p < 0.05). Regarding intestinal morphology, supplementation with 180 or 240 mg/kg CEO increased jejunal villus height (VH) and the villus height to crypt depth (VH/CD) ratio compared with the control group (p < 0.05). Furthermore, 240 mg/kg CEO supplementation augmented the ileal VH/CD ratio relative to the control group (p < 0.05). For antioxidant status, 180 mg/kg CEO supplementation elevated serum glutathione peroxidase (GSH-Px) activity in piglets relative to the control group (p < 0.05). Importantly, no differences were found between the 180 mg/kg and 240 mg/kg CEO groups across all measured parameters (p > 0.05). In conclusion, dietary inclusion with 180 mg/kg CEO is recommended for weaned piglets, given its comprehensive benefits in alleviating diarrhea, improving nutrient digestibility, enhancing intestinal morphology, and bolstering antioxidant status.