Effects of Essential Oil Blends Supplementation on Growth Performance, Meat Physiochemical Parameters, Intestinal Health and Lipid Metabolism of Weaned Bamei Piglets

The benefits of plant essential oils (EO) on the health of animals have been frequently reported, but their alteration of lipid metabolism in obese pigs has yet to be explored. This study aimed to assess the impact of EO blends (oregano, cinnamon and lemon oils) on growth performance, meat physicochemical parameters, intestinal health and lipid metabolism in the small intestine of weaned Bamei (a kind of obese-type pig) piglets. One hundred and forty-four male 60-day-old weaned Bamei piglets were randomly assigned to three groups of six replicates each: CON (basal diet), T1 (basal diet + 250 mg/kg EO), and T2 (basal diet + 500 mg/kg EO) over 28 days. The results showed that T1 trended to improve the average daily gain and feed intake to body gain ratio (p < 0.1), reduced water loss (p < 0.05), and increased the redness of meat (p < 0.05) compared to the CON. In addition, a significant change in the proportion of C17:0 and C20:1 was observed in the meat of T1 (p < 0.05). Improved intestinal health was evidenced by the reduced crypt depth, improved villi-to-crypt length ratio, and better superoxide dismutase activity in T1 (p < 0.05). Further study on intestinal lipid metabolism showed that duodenal lipase activity and the mRNA expression levels of lipid transport-related genes in the jejunum (FABPs, APOA1, APOB and ACSL3) were significantly reduced, alongside diminished serum lipid metabolites (Total protein and triglyceride) in the groups fed with EO (p < 0.05). In short, EO supplementation especially at 250 mg/kg improved intestinal health and inhibited lipid metabolism, which had a positive effect on the overall performance of Bamei piglets. This new evidence contributes to understanding the early regulatory role of EO in obese pigs and their potential to alleviate adolescent obesity.