摘要：

A 53-day field trial was performed to evaluate the effects of the essential oils of cinnamaldehyde, eugenol, and capsicum on the health status and growth performance of 45 Charolais beef cattle (average arrival weight: 422.0±29.3kg; control: n =21; treated: n =24). Each animal was weighed, and blood samples were collected on days 0, 25, and 53. The average daily gain of the treated group was significantly higher ( P <0.05) than that of the control. The treated group showed a significant increase in antibody for BHV-1 after vaccination ( P <0.05 at day 25 and day 53) and significantly higher serum bactericidal activity ( P =0.01). No differences between groups were observed for serum content of haptoglobin or reactive metabolites of oxygen. The observed improvement in growth performance and health status is due to the capacity of essential oils to optimize rumen fermentations, to increase dry matter intake, and probably to the positive interaction between essential oils and immune system components.

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