Effects of oral administration of various essential oils on blood metabolites, intestine development, microbial enumeration and meat quality in broilers

A total of eighty 21-day-olds (1.1±0.01kg) ROSS 308 broilers were randomly allocated into 4 groups, with 20 replicates per group and 1 chicken per replicate per cage. Three experimental groups (CAR, THY, ORE group) were given oral administration of 200iL essential oils (carvacrol, thyme and oregano) at 18:00h every day. The results showed no significant differences on blood metabolites among each group (P>0.05). The villus height of the small intestines in the CAR group increased significantly (P<0.05) from 1360.10 to 1552.54im as compared to the control group, the goblet cell counts in the THY and ORE groups significantly increased by 20.91% (P<0.05) and 31.82% (P<0.05), respectively, compared to the control group. The E.coli and Salmonella in ORE group significantly decreased by 11.16% (P<0.05) and 9.54% (P<0.05), respectively, compared to the control group. The Redness (a*) values of the muscles of the CAR and ORE groups were observed to increase significantly (P<0.05) from 3.58 to 7.95 and 6.86, respectively, compared to the control group. In conclusion, oral administration of the essential oils carvacrol, thyme, and oregano promoted intestinal development, improved the intestinal environment and the meat quality of broilers.