Effects of the nebulisation of Lavender Essential Oil on the behaviour, skin and tail lesions of growing pigs

Lavender (Lavandula angustfolia) Essential Oil (LEO) is a calming phytoextract that could be administered by inhalation to pigs to reduce anxiety/aggression and improve animal welfare [1-3]. This trial tested its effects on some welfare indicators during the growing phase. Fifty-six crossbred barrows (44kg BW) with undocked tails were allotted to two experimental groups, each including 4 pens of 7 pigs. In the LEO group room, a 1% solution of lavender oil was vaporized for 10min twice a day. The trial lasted 63 days. Individual behaviour, body weight, skin and tail lesions were assessed at three timepoints (beginning, middle and end of the trial). Data were submitted to ANOVA using the group as the main effect. For severity classes distribution of tail lesions, the Chi-squared test was used. No difference emerged between groups in growth parameters. The overall level of activity was not affected by the experimental group (recumbency occupied 56.7 vs. 58.2% of the day in CON vs. LEO, respectively, P>0.05). Total overall number of body lesions was significantly reduced in LEO compared to CON (6.6 vs. 9.3, P=0.002) as well as the severity of tail lesions (76 vs. 53% of intact tails, 19 vs. 39% of mild damages and 6 vs. 8% of severe damages, P=0.007). Although the positive effects of LEO nebulisation were not strong enough to modify the overall behaviour, a decrease in animals’ aggressiveness and tail/skin damage was recorded over the long period. However, further trials are recommended under farm conditions and on larger animal numbers.