In commercial livestock production, both beef and dairy cattle are periodically exposed to short periods of feed restriction (FR). Previous studies in sheep have demonstrated a reduction in absorptive function after a period of feed deprivation; however, to our knowledge there is no data describing the effects of FR in cattle on rumen epithelial function. To gain a further understanding of the impacts of FR and potential modes for mitigation, we will evaluate the absorptive and barrier functions and indicators of immune activation by the rumen epithelium. The underlying hypotheses are that 1) FR reduces absorptive function, 2) FR increases tissue permeability and, consequently, results in activation of the innate immune response, 3) the impact of FR on epithelial function and time required for recovery is dependent on the severity of FR, and 4) the provision of diets promoting a longer rumen residence time decrease the impact of FR on epithelial function. Two studies will be conducted to address the above mentioned hypotheses. The first study will examine how the severity of FR impacts epithelial absorptive and barrier functions, related immune functions, and will determine the time required for recovery. The second study will test one possible nutritional strategy to mitigate the impact of FR. The proposed studies are expected to provide new information on how different degrees of FR impact rumen epithelial function and including absorptive, barrier and immune system modulation in cattle. This will provide the basis for the initiation of research focusing on the development of nutritional management strategies to mitigate the effect of FR on animal health and performance.