effects of rosemary (rosmarinus officinalis l.) essential oils on digestibility, blood and rumen parameters of ghezel sheep

this study was conducted to evaluate effects of rosemary essential oils (reo) on feed digestibility, blood and rumen parameters of ghezel sheep. four male sheep with average body weight 46±2 kg were used in a 4×4 latin square design. treatments composed of basal diet (control) in addition to diets containing 100 (ro100), 200 (ro200) and 400 (ro400) mg/day of reo.  sheep&apos;s fed with 4 diets at 4 periods of 21 days (14 days as adaptation and 7 days for sample collection). digestibility was determined by fecal collection method. on 20 day of the experimental period, ruminal liquor samples were taken at 0, 2, 4 and 6 hours after feeding for rumen ph, n-nh3 and total volatile fatty acids measurements. on the last day of each measurement period, blood samples were taken at 0 and 4 hours after feeding, via jugular vein, and analyzed for glucose, urea, and total protein and creatinine contents. the results showed that ruminal total volatile fatty acids in ro100 diet were lower than control and ro200 diets (p˂0.05). ruminal ammonia concentration in control diet was higher than ro100 diet at all sampling times and also ro200 diet was higher than ro100 and ro400 diets (p<0.05). blood creatinine concentration in control diet was higher than ro400 diet at 4 h after feeding (p<0.05). in conclusion, treatment of 200 mg/day reo may have positive effect on feed digestibility and rumen fermentation of sheep; however more experiments are required in this field.