Comparing the effects of a combined phytogenic feed additive with an individual essential oil of oregano on intestinal morphology and microflora in broilers

The effects of dietary supplementation of oregano essential oil (OEO) and a commercial blend of phytogenic (CBP) on intestinal properties, the number of ileal Escherichia coli and Lactobacillus were investigated in broilers. Two hundred 1-d-old broiler chicks were assigned to 4 dietary treatments that include: (1) Control (without phytogenic), (2) CBP (150ppm), (3) OEO (300ppm) and (4) OEO (500ppm). Each of the 4 diets was fed to 5 replicates of 10 chicks from hatching to 42d of age. Jejunal and ileal villi height increased and mascularis thickness decreased by 300ppm OEO; however, villi surface area and villus height to crypt depth ratio were higher and crypt depth was lower in jejunum compared with control or those fed CBP in the diet (P<.05). In comparison to broilers fed control, CBP and either level of OEO reduced (P < .01) ileal E. coli count at d 21, whereas Lactobacillus count was not different among treatments. From the results, it was concluded that supplementation of 300ppm OEO in broilers' diet could improve morphometric parameters of the small intestine and reduce the presence of E. coil in ileal content.