Oregano essential oil administration diminishes the imbalances of certain serum biochemical parameters in diarrheic calves
Neonatal diarrhea syndrome is the most common disease occurring in calves aged less than 15 days and is often accompanied by dehydration, pre-renal azotemia and electrolyte imbalances. The objective of this study was to investigate under field conditions whether the daily administration of oregano essential oil could ameliorate the imbalances of certain biochemical parameters observed in calves with neonatal diarrhea syndrome: Thirty-seven diarrheic calves that did not require intravenous administration of fluids until recovery were divided into two groups; Eco group (n=23) calves were orally drenched with Greek oregano (Origanum vulgare ssp. Hirtum) essential oil at the dose of 12.5 mg/kg body weight once per day for the first 10 days of their life whereas those of Conts group (n=14) were left untreated and served as controls. All animals were monitored daily for the incidence of diarrhea and their fecal score was recorded. Blood samples were collected by jugular venipuncture at the age of 48h (D2) and 24h after the recovery from diarrhea (D1PD): Mean serum concentrations of albumin, blood urea nitrogen (BUN), creatinine, potassium (K), and inorganic phosphorus (P) were significantly increased (P<0.05) during diarrhea episodes whereas the concentration of total calcium (Ca) and the activity of aspartate aminotransferase (AST) was significantly decreased (P<0.05). On D1PD, the average serum concentrations of albumin, BUN, creatinine, K, and P were significantly lower and the concentration of Ca was significantly higher in ECO group compared to the controls: These results indicate that oregano essential oil administration could prevent the impairment of renal function of neonatal diarrheic calves and ameliorate the serum K, P and Ca imbalances.