Óleo essencial de alecrim (Lippia gracilis Shauer) sobre o desempenho e a expressão gênica de codornas japonesas

Aromatic essential oils have a low risk of accumulating in animal tissues due to the rapid metabolization and short half-lives of their active compounds, which can act directly on pathogenic microorganisms promoting their inhibition. Thus, it has the potential to be used as growth promoters and, possibly, to replace the antibiotics and promoters commonly used in animal diets. The carvacrol and thymol phenolic compounds, major components of rosemary essential oil (Lippia gracillis shauer), are the main responsible for antimicrobial and antioxidant action of this oil. However, there is little research to evaluate the effect this additive as growth promoter in quails. The objective was evaluate the action of rosemary essential oil as promoter of growth in the Japanese quail organism. A total of 252 quail (Coturnix coturnix japonica) were used, distributed in a completely randomized design, within three treatments, seven replicates and twelve animals per experimental unit of from 2 to 35 days of age. The treatments were: basal diet, basal diet with inclusion of 400 mg/kg of rosemary essential oil and basal diet with inclusion of 500 mg/kg of bacitracin methylene disalicylate (BMD). The parameters of performance, intestinal microbiology, blood biochemistry, lipid peroxidation in the quail duodenum, liver and genes expression of cotransporter Sodium-glucose 1 (SGLT1), glucose transporter 2 (GLUT2), catalase (CAT) and glutathione peroxidase 7 GPX7). After the experimental period, 6 birds with the average weight of the plot of each treatment were euthanized for collection of blood and liver samples for further analysis. For microbiological analysis, two other animals from each experimental unit (n=14) were euthanized to collect intestinal contents. The data were submitted to analysis of variance and the means were compared using the Tukey test at 5% probability, except for the microbiology that was analyzed descriptively. When compared to the chemical antimicrobial, the essential oil promoted lower feed intake (P0.05) between treatments with regard to lipid peroxidation in the liver and on the activity of AST and ALT enzymes in the blood. Lower levels of uric acid (P0,05) entre os tratamentos com relação a peroxidação lipídica no fígado e sobre a atividade das enzimas AST e ALT no sangue. Menores níveis de ácido úrico (P<0,01) e creatinina (P<0,02) foram encontrados no tratamento com antimicrobiano convencional comparado ao tratamento controle. As aves do tratamento controle apresentaram maior expressão de SGLT1 (P<0,01) e as do tratamento com adição de óleo essencial promoveram menor expressão de CAT e GPX7 (P