Effects of oregano essential oil on growth and hematogenic immunity ofnewborn calves

The objective of this study was to analyze the effects of oregano essential oil, which is a natural additive, on the growth and hematogenic immunity of newborn calves. Fortynewborn calves were selected, and divided into experimental and control groups, in this study, on the basis of their dates of birth,with 20 calves in each group. Oregano essential oil was added to the concentrate for calves in the experimental group ata proportion of 40 g·t-1. Indices of growth performance and hematogenic immunity were tracked, and analyzed in the calves from their birth to 70 days. The results showed that with increase inthe time of the growth and development of thecalves, weight, height, body length, chest circumference, abdominal circumference, pasterncircumference, total serum protein levels, levels of immunoglobulins G, A, and M, and average feed intake were significantly higher in the calves of the experimental group than those in the control group (P<0.01); the incidence of diarrhea in the calves in the experimental group reduced markedly(P<0.01). Overall, the study showed that the concentrate with added oregano essential oil could boost the growth, immunity, and feed intake of calves, and reducediarrhea morbidity, which was suggested in the results.