عنوان مقاله [English]
Introduction Antibiotics as growth promoters in poultry feed are posing serious health risks to human health. Because of their residual effects in poultry meat and eggs, and pathogens developing resistance to antibiotics. Currently, poultry scientists are challenged to find out alternatives to antibiotic growth promoters with no side effects for poultry that could be more or as effective against harmful microorganisms in the gastrointestinal tract and to stimulate the growth by increasing the efficiency of feed utilization and to enhance the immunity. Regarding to this subject, supplementing the dietary herbs or plant extracts would stimulate the productive performance of poultry. Tanacetum balsamita contains various has a rich secondary metabolite with diverse biological and therapeutical activities. These compounds consist of essential oil or volatile oil (monoterpenes and sesquiterpens), phenylpropane derivatives, flavonoids (Flavonols, apigenine derivatives, scutellareine derivatives and luteoline derivatives), tannins and oligo-elements that has antioxidant effects on poultry. Its powder or watery or ethanolic extract influenced broiler or laying hen performance and blood metabolites. In all of the reports, researchers used only powder or extract not essential oil and hence there was not any comparison between this plant with antibiotics and some antioxidant vitamins. The aim of this study was the comparison between Tanacetum balsamita essential oil with antibiotics and vitamin E and C as synthetic antioxidants on broiler chicken performance and blood metabolites.
Materials and Methods Three hundred Ross-308 broilers from 1 to 42 days of age were used in a completely randomized design in 6 treatments and 4 replicates and 10 birds in each. The dietary treatments consisted of: 1) basal diet as control group, 2) basal diet supplemented with 200 mg/kg Tanacetum balsamita essential oil, 3) basal diet supplemented with 400 mg/kg Tanacetum balsamita essential oil, 4) basal diet supplemented with 200 mg/kg Vitamin E, 5) basal diet supplemented with 200 mg/kg vitamin C and 6) basal diet supplemented with 200 mg/kg virginiamycine antibiotic. Tanacetum balsamita essential oil extraction was done by Giah-Essanse Company in Golestan Province. The diets were formulated to meet the requirements of broilers as established by the Ross 308 broilers feeding guide in starter (1-12 d), grower (11-25 d) and finisher (26-42 d). The birds were kept under conventional conditions for vaccination, temperature, ventilation, and lighting based on Ross 308 catalogue recommendations. Standard management practices of commercial broiler production were applied. The broiler diets were formulated based on standardized ileal digestible amino acids and other requirements were obtained from Ross catalogue recommendations. Broiler chicken performance (feed intake, body weight gain, feed conversion efficiency and European production efficiency factor), blood metabolites like (triglyceride, total cholesterol, HDL and LDL Cholesterol) and carcass and abdominal fat percentage were calculated. Breast and tight meat fat and protein percentage and color (based on L, a, b scale as brightness, yellowness and redness respectively) were detected. Finally, population of Lactobacillus and Escherichia coli of ileum were detected.
Results and Discussion The results showed that feed intake, body weight gain, feed conversion ratio and European production efficiency factor (EPEF) were not significantly affected by dietary treatments. Chickens received diet containing vitamin E had higher HDL-cholesterol concentrations compared to control and other dietary additives (P < 0.05) while triglyceride, total cholesterol and LDL-cholesterol did not influence by experimental treatments. Thigh and breast meat Color (brightness, yellowness and redness), fat and protein percentage, carcass and abdominal fat of thigh meat and protein percentage of breast meat were not affected by additive while addition of Tanacetum balsamita essential oil significantly reduced the protein percentage of breast meat (P < 0.05). Chickens received diet containing 400 mg/kg Tanacetum balsamita essential oil and E and C vitamins had a higher ileal lactobacillus population than control group (P < 0.05). However, there was an increase in the number of E. Coli in ileum of chickens fed diets containing Tanacetum balsamita essential oils was not significantly different with that of control birds.
Conclusio: In conclusion, supplementation of Tanacetum balsamita essential oil had no effect on growth performance and carcass parameters and blood metabolites of broiler chickens while higher level of Tanacetum balsamita essential oil increased of Lactobacillus population. This experiment was done in a common condition without any challenge and antioxidants such as vitamin E and C or some essential oils may affect broiler chicken performance during some challenge. It is suggested that it may be beneficial if this herb or its essential oils added to broiler chicken diet with some challenges like heat and cold stresses.