TY - JOUR ID - 3284 TI - Effect of thymol and carvacrol on nutrient digestibility in rams fed high or low concentrate diets JO - Iranian Journal of Veterinary Research JA - IJVR LA - en SN - 1728-1997 AU - Zamiri, M.J. AU - Azizabadi, Elham AU - Momeni, Zahra AU - Rezvani, Mohammad Reza AU - Atashi, Hadi AU - Akhlaghi, Amir AD - Department of Animal Science, College of Agriculture, Shiraz University, Shiraz, Iran AD - Post-Graduates, College of Agriculture, Shiraz University, Shiraz, Iran AD - Post-Graduates, College of Agriculture, Shiraz University, Shiraz, Iran Y1 - 2015 PY - 2015 VL - 16 IS - 4 SP - 335 EP - 340 KW - Carvacrol KW - Digestibility KW - Essential oils KW - Sheep KW - thymol DO - 10.22099/ijvr.2015.3284 N2 - Published data on the effects of essential oils (EO) on in vivo nutrient digestibility in sheep are contradictory. In 2 experiments, the effect of thymol and carvacrol on nutrient digestibility was studied in sheep fed with high (70%) or low (52%) concentrate diets, using incomplete Latin Square designs. The essential oils were mixed with the concentrate portion of the diet at the rate of 0.0, 0.3, or 0.6 g per kg dry matter (DM) diet. Supplementation of thymol had no significant effect on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and acid detergent fiber (ADF). The main effect of thymol on neutral detergent fiber  (NDF) and ether extract (EE) digestibility and on nitrogen balance (NB) was significant (P<0.05), but within each level of dietary concentrate no significant differences were observed for these measurements. Overall, ruminal ammonia concentration was higher (P<0.05) in both HCD and LCD lambs receiving 0.3 mg thymol per kg diet. Supplementation of carvacrol had no significant effect on nutrient digestibility. The main effect of carvacrol on ruminal ammonia levels and NB was significant, but within each level of dietary concentrate no significant differences were observed in ammonia levels and NB. Inclusion of 0.3 g/kg diet DM of carvacrol or thyme was more effective than 0.6 g/kg diet DM in terms of NB but neither dose affected nutrient digestibility. Future research should determine the long-term effects of essential oils on digestibility and performance in sheep, before recommendation can be made for their use under practical husbandry conditions. UR - https://ijvr.shirazu.ac.ir/article_3284.html L1 - https://ijvr.shirazu.ac.ir/article_3284_02bf131de39f1b72b2dd89f3a73546fb.pdf ER -