The Effect of Lavandula Angustifolia Essential Oil on Performance, Blood Metabolites and Nutrient Digestibility in Broiler Chickens

Introduction The lavender essential oil is traditionally believed to be antibacterial, antifungal, carminative (smooth muscle relaxing), sedative, antidepressive and effective for burns and insect. Lavender oil (primarily L. angustifolia) has also been found to be active against many species of bacteria and fungi. However, a few reports are available on the effect of lavender essential oil on poultry performance. The objective of this study was to evaluate the effect of lavender essential oil on performance, blood metabolites and apparent nutrient digestibility in male broiler chicks.
Materials and Methods A 42-day trial was conducted to evaluate the effect of adding different levels of lavender (Lavandula angustifolia) essential oil to diet on performance, blood parameters and ileal nutrient digestibility. The feeding program consisted of starter (1-10 d), grower (11-24 d) and finisher (25-42d) diets. There were 5 treatments group: control; virginiamycin 10% (50 ppm); and three levels of lavender essential oil (350, 525 and 700 ppm). Body weight, feed intake and feed conversion ratio were recorded at the end of starter, grower and finisher periods. On d 28, blood samples were gathered from wing vein of 1 chick in each experimental unit. Blood samples were centrifuged (15 min, 3000 rpm) to separate sera, and then cholesterol, TG, HDL, LDL and VLDL were determined. Then one chick from each pen was killed by ketamine injection and ileal digesta was collected.
Results and Discussion At 42 days of age, Chickens receiving diet containing virginiamycin showed the highest feed intake. Birds fed diets containing 525 and 700 ppm lavender essential oil numerically had more feed intake than birds fed control diet, but this difference was not significant. Broilers fed diet containing virginiamycin showed the highest weight gain and the control diet showed lowest weight gain at the end of the experiment. The lowest level of serum cholesterol was observed in 350 ppm lavender essential oil treatment. Essential oil treatments also caused lower serum high density lipoprotein (HDL) than virginiamycin and control treatments. There were no significant differences among treatments for feed conversion ratio, blood triglyceride, low density lipoprotein (LDL), very low density lipoprotein (VLDL) and ileal digestibility of dry matter, ether extract, crud protein, ash and organic matter of diets. Positive effects of essential oils on feed intake have been reported previously. Improved growth performance could be attributed to the presence of essential oil in the diet, which encourages secretions of endogenous digestive enzymes, which then enhance nutrient digestion and gut passage rate in chickens. It seems that phytogenic feed additives improved apparent ileal digestibility of nutrients at 21, 35, and 42 d of age. In contrast, there are studies where the effects on animal performance were not significant. However, in our experiment lavender essential oil caused a numerical increase in digestibility and its effect was not significant, but the improved weight gain in this experiment may be due to lavender essential oil effect on villus surface area and gut microflora. Also dietary supplementation of a mix of essential oils at 300 g/t, significantly increased villus width and surface area, indicative of improved nutrient absorption and performance. The effects of lavender essential oil on the intestinal microflora were not evaluated in this study; however, others have shown that essential oil have the capacity, when fed to broilers, to reduce the growth of E. coli and C. perfringens and increase the numbers of Lactobacillus spp. Similarly, the inclusion of thyme, marjoram, and rosemary in broiler diets reduced the numbers of cecal C. perfringens by >1 log. The contributory factors causing these differences reported in other studies could be attributed to the differences in the inclusion levels of essential oil, sources of herbs used to form blend of essential oil, basal diet composition, or the microbial environment in which the birds were reared. It has been suggested that birds fed essential oil have reduced concentrations of serum cholesterol and that the hypocholesterolemic effect of essential oil is due to compounds in essential oil that have the ability to inhibit hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase activity, a key regulatory enzyme in cholesterolsynthesis.
Conclusion According to the results of this experiment, lavender essential oil had lower effects on performance than antibiotic, but adding lavender to diets could have beneficial effects on weight gain and serum cholesterol levels in broiler chickens. However, more evidence is needed to clarify whether lavender essential oil can match the effects of antibiotics as feed additives in poultry diets.