This study investigated the effects of supplementing a commercial phytogenic powder containing a blend of peppermint, coriander, cumin, and anise essential oils on growth performance, blood parameters, and health status of Holstein suckling calves. Thirty-six newborn female Holstein calves were randomly assigned to one of three dietary treatments: 1) a control diet (no experimental powder); 2) a diet supplemented with 2 kg of the essential oil blend powder per ton of starter (EO2); and 3) a diet supplemented with 4 kg of the essential oil blend powder per ton of starter (EO4). Calves were weaned at 79 days of age, and the trial continued for 21 days post-weaning. Average dry matter intake, feed efficiency, body weight, and average daily gain were significantly greater (P<0.05) for calves fed the EO2 diet compared to the other treatments. Similarly, average withers height and average daily height gain were also significantly improved (P<0.05) in the EO2 group. Mean blood urea nitrogen concentration was significantly higher (P<0.05) in the EO2 treatment, while mean serum glucose concentration was significantly lower (P<0.05). Regarding health, the EO2 treatment exhibited significantly better scores (P<0.05) for nasal discharge, cough, and eye discharge compared to the control and EO4 treatments. No significant differences were observed among treatments for fecal score or ear status. In conclusion, the addition of 2 kg of the tested essential oil blend powder per ton of starter improved growth performance and health status in Holstein suckling calves, primarily by increasing dry matter intake.
SOHRABIFAR et al. (Thu,) studied this question.