Yang, W. Z., Oba, M., Swift, M. L. and McAllister, T. A. 2014. Short Communication: Variation in response to processing, in vitro gas production and fermentation of western Canadian feed barley. Can. J. Anim. Sci. 94: 725-729. Sixty feed barley samples were collected from various locations in western Canada. Samples were either ground (1 mm) or dry-rolled to a processing index of 80%, and fermentability was assessed by measuring gas production (GP) and dry matter disappearances (DMD) at 0, 4, 8, 14 and 24 h of incubation using a batch culture technique. Physical and chemical composition, and GP and DMD varied substantially among samples. There were significant correlations among test weight and nutrient content of barley with GP and DMD of ground barley. The results indicate that the impact of nutrient content on in vitro DMD is more easily detected with ground than rolled barley.