Abstract
The objective of this study was to investigate the effects of replacing antibiotics with a combination of plant essential oils on the growth performances and gastrointestinal health of broilers. A total of 720 1-day-old male AA broilers were randomly divided into 3 treatments: the control treatment (CON), the Aureomycin supplementation treatment (AGP), and the combined plant oils supplementation treatment (POC), with a 42-D period feeding procedure. Growth performances, carcass performances, intestinal sections, and cecal microbiota were investigated. Results indicated that POC supplementation decreased the feed conversion ratio compared with CON and AGP treatments, though not significantly. No significant differences were found for feed intake, BW gain, and culling rate among the 3 treatments (P > 0.05). In addition, no significant differences were seen on carcass performance. For the aspects of intestinal section, POC supplementation did not make significant effects on intestinal wall thickness, villus heights, crypt depths, and the ratio of villus heights/crypt depths compared with CON and AGP treatments. Cecal microbiota results demonstrated that bacterial diversity and some representative probiotic bacteria were significantly increased in numbers (P < 0.05) after POC supplementation. In conclusion, the combination of essential oils promoted intestinal health through improving gut bacterial diversity and probiotic bacteria, as well as improving feed conversion ratio of broilers. These results indicated that the combination of essential oils may benefit the gastrointestinal health and be applied as an antibiotic alternative.