Effect of Essential Oil of Laurel (Laurus nobilis L.) on Performance, Blood and Fecal Parameters of Holstein Calves during Suckling Period

The objective of this study was to analyze the effect of Laurus nobilis L. essential oil (600 mg/day) on performance and blood parameters of Holstein calves. The study was started with total of 24 calves, randomly categorized into two groups of 12 (6 males and 6 females) however, it was completed with 23 calves because of dying a female at the 8th week of the trial. Addition of Laurel essential oil into whole milk did not cause any significant change in weekly live weight gain (kg), total weaning live weight gain (kg), weekly chest girth measurements (cm), weaning chest girth (cm), dry matter, roughage and concentrate feed consumption (gr), total milk consumption (kg), feed conversion ratio (kg), total cost and unit cost (P>0.05). However, essential oil contained calf's milk decreased fecal evaluation score and number of days with diarrhea (P<0.05). The calf's serum total cholesterol, glucose, AST, GGT, creatinine, phosphor, calcium, insulin, total T3, total T4, albumin, GH and globulin concentrations did not differ between the groups (P>0.05). Essential laurel oil containing whole milk, on the other hand, lowered serum triglyceride concentration (P<0.05). Altogether these results suggested that the consumption of laurel essential oil (600 mg/day) containing whole milk by calves might have positive influences on their health parameters compared to the control group.