This study was conducted to evaluate the effect of a blend of essential oils (EOB) derived from thyme (Thymus vulgaris), peppermint (Mentha piperita) and eucalyptus (Eucalyptus globules) as a natural growth promoter. Five dosages (0 (CON), 50, 100, 150 and 200 ppm) of EOB were added daily to the drinking water to determine its effect on growth performance, carcass quality, blood biochemistry, immune response and ileal morphology in Ross 308 broiler chicks. A total of 500, 10‐day‐old male Ross 308 broilers were allocated into five treatments with four replicates each. Inclusion of EOB at 150 ppm improved (p < 0.05) body weight gain, feed conversion ratio and production index by 11.73, 10.81 and 24.13% compared to CON respectively. The inclusion of EOB at 100, 150 and 200 ppm increased (p < 0.05) carcass yield and thigh muscle compared to CON. Serum concentration of hepatic enzymes (alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase) was decreased while the ileal villus height and ratio of villus height to crypt depth were improved (p < 0.05) in response to inclusion of 150 and 200 ppm of EOB compared to CON. The ileal Escherichia coli count was lower and Lactobacillus count was higher in EOB‐200 and EOB‐150, respectively, compared to CON at 21 and 42 days of age (p < 0.05). Antibody titre of Newcastle, bronchitis and infectious bursal disease was linearly increased (p < 0.05) by increasing supplemental level of EOB at day 4 post‐inoculation. Our results suggested that supplementation of EOB at the 150 ppm into drinking water during day 11–42 could improve growth performance, humoral immunity and ileal morphology and microflora in broilers, and thus, EOB has merit to be used as an alternative to antibiotic growth promoters.
A total of 500, 14-d old male Ross 308 broilers were allocated into five treatments (4 replicates each) including: a negative (NC) and positive control diet (PC) which supplemented without and with 7% poultry by-product meal (PBPM), respectively and three levels of additive supplementation of thyme and rosemary powders in the basal diets: 0.750% rosemary powder (PCR); 0.375% thyme powder + 0.375% rosemary powder (PCRT), and 0.750% thyme powder (PCT) rosemary powder. The PCRT diet improved (p <0.05) average daily gain and feed conversion ratio by 5.62 and 10.37% compared to PC, respectively. The serum concentration of lipids (triglycerides, cholesterol, high-density lipoprotein, and low-density lipoprotein) was decreased while the ileal villus height and ratio of villus height to crypt depth as well as ileal microbiota population were improved (p <0.05) in response to inclusion PCRT diet compared to PC diet. The blood serum concentration of malondialdehyde was statistically decreased (p <0.05) by supplementation of PCRT in broiler diets. Our results suggested that supplementation of a blend of thyme and rosemary powders at the level of 0.375% of each into broiler diet during d 14-42 has merit to be used as a natural antioxidant in diets formulated by PBPM.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.