The objective of this study was to investigate the effects of thyme methanolic extract on ruminal dry matter (DM) degradation parameters of sunflower meal. Treatments were: sunflower meal (no additive), thyme methanolic extract (0.3 ml/30 ml buffered rumen fluid). In situ rumen degradability was performed with of three Gezel rams rumen fistulaed in times at 0, 2, 4, 8, 16, 24 and 48 h. The results showed that dry matter disappearance at 24 h incubation, were 65.89 and 54.14 percent for sunflower meal and thyme methanolic extract (0.3 ml/30 ml buffered rumen fluid) respectively. Dry matter disappearance at 48 h incubation, were 79.16 and 73.98 percent for sunflower meal and thyme methanolic extract (0.3 ml/30 ml buffered rumen fluid) respectively. Water soluble fraction (a) for sunflower meal and thyme methanolic extract (0.3 ml/30 ml buffered rumen fluid) were estimated, 19.76 and 17.14%, respectively. Effective rumen degradable dry matter for sunflower meal and thyme methanolic extract (0.3 ml/30 ml buffered rumen fluid) at a rate of 0.02/h, 61.53 and 66.46%, respectively were estimated. Potentially degradable fraction (b) for sunflower meal and thyme methanolic extract (0.3 ml/30 ml buffered rumen fluid) were estimated, 57.05 and 72.6%, respectively. Thyme methanolic extract (0.3 ml/30 ml buffered rumen fluid) treatments significantly decreased dry matter degradability of sunflower meal on different incubation times. Although thyme methanolic extract (0.3 ml/30 ml buffered rumen fluid) decreased (p<0.05) the water soluble fraction (a) but increased (p<0.05) the potentially degradable fraction (b) of DM, constant rate of degradation (c), total degradability (a+b) and Effective Rumen Degradability of Dry Matter (ERDM) at a rate of 0.02, 0.05 and 0.08/h.
