EFFECT ON THE CORTISOL SERUM LEVEL OF GROWING PIGS SUPPLEMENTED WITH ESSENTIAL OIL OF Lippia alba

Animal welfare has become more important as the consumer market is increasingly demanding good conditions of handling production animals, especially in swine farming. There is also scientific evidence of economic losses due to animal stress during growth and before slaughter, reducing body weight, carcass yield and meat quality. Thus, natural and economically viable therapeutic alternatives were researched, such as the use of herbal medicines, aiming to minimize these negative effects on animals. With emphasis on Lippia alba, a plant commonly used in Brazilian medicine with proven efficacy as a relaxant and antiparasitic, anti-inflammatory, anesthetic and anti-stress for most animal species. The aim of this study was to evaluate the effect of L. alba essential oil supplementation on the reduction of serum cortisol levels in growing pigs and as a welfare parameter to evaluate these animals. Twelve F1 castrated pigs with an average weight of 12.3 kg were divided into two groups of six animals. Control group (A1) received saline solution at a dose of 1 mL.kg-1 and treatment group (A2) 0.5% L. alba essential oil at a dose of 1 mL.kg-1 on days 0, 30, 60 and 90 by gavage. During these time points, blood was collected from the auricular vessel to measure cortisol levels using the radioimmunoassay technique (Kit Cort-CT2). The administration of L. alba essential oil showed a significant anti-stress effect in growing pigs, significantly decreasing blood cortisol levels, an indicator of animal welfare.