Cellular Immune Response of Weaned Pigs Fed Diet Supplemented with an Essential Oil

The objective of the present study was to investigate the effect of an essential oil product on growth performance and cellular immune response of 28-day-old weaned piglets. A total of 348 piglets (50% gilts, 50% barrows) were assigned to three dietary treatments (6 pens/trt). Th e basal diet was a commercial feed that was supplemented without any growth promoter (NC), with antibiotic growth promoter of 40 ppm avilamycin (PC), or with 0.25 g of an essential oil product (EO) per kg of feed. All pigs were immunized by inactivated Aujeszky’s disease virus vaccine at week one and three of the experiment (28- and 44-days-age, respectively). Blood samples were taken four times (on day one, 16, 24, 32 of the experiment) for lymphocyte stimulation (LST) tests with ConA, PWM, PHA used as non-specific and Aujeszky virus used as specific mitogens from 2 pigs/pen. All piglets were individually weighed on day 0, 8, 16, 24 and 32 of the trial. There was no significant difference among average daily gain, feed intake and feed conversion ratio of piglets fed different dietary treatments. The non-specific LST test at the 4th blood sampling showed higher values in pigs received feeds with essential oil supplementation (EO) than that of the positive (PC) and negative control (NC) groups (P