Effects of nature identical essential oils (carvacrol, thymol and cinnamaldehyde) on growth performance of piglets and non-invasive markers of antioxidant status and calprotectin release

The post-weaning phase is one of the most critical periods in pig production due to many stress factors that may negatively affect the response of the immune system and lead to intestinal gut dysfunction in pigs. The use of products of natural or synthetic origin could support the animals' health in this stressful situation. The aim of this study was to evaluate the effects of nature identical essential oils (SEOs; carvacrol, thymol and cinnamaldehyde) added to post-weaning piglets' diet on growth performance, fecal antioxidant status and calprotectin (CALP) release. At weaning, a total of 72 crossbred piglets were randomly assigned to three dietary treatments: a control group fed with the basal diet (CTR) and treatment groups fed with the basal diet with either a low dosage of SEOs (T1, 50 ppm) or a high dosage of the product SEOs (T2, 100 ppm). The body weight (BW) was measured at 0, 14 and 42 days, and the average daily gain (ADG), average daily feed intake (ADFI) and feed efficiency (FE) were calculated at the end. From fecal samples, we measured the total antioxidant capacity (TAC), by FRAP and ABTS assays, and the CALP release. The ADG was higher in the treated groups (p < 0.05), although there was no significant effect of a treatment x time interaction. No significant differences were detected between the groups for BW, ADFI and FE. As for the antioxidant activity, the FRAP after SEOs administration showed a significant (p < 0.05) reduction at the end of the trial, probably due to an accumulation of a complex mixture of antioxidant compounds and a consequent underestimation of the antioxidant capacity. Calprotectin, a marker of gut inflammation, decreased in the SEOs-treated groups with a significant (p < 0.05) time effect after 42 days. The results of this study demonstrate that the use of a natural extract can improve some parameters of growth performance and gut health.