Effects of Low Feed Intake on Gastrointestinal Function

Low feed intake for beef cattle occurs in association with weaning, parturition, heat stress, transportation, newly received feedlot cattle, and for cattle with metabolic disorders, digestive disorders, and infectious disease. Based on recent studies, it is clear that low feed intake not only reduces nutrient supply but also decreases short-chain fatty acid absorption across the ruminal epithelium and when severe, can decrease gastrointestinal barrier function. The reduction in nutrient absorption and increased risk for molecule translocation across the gastrointestinal tract predispose cattle to a short-term energy deficit. In addition to the effects arising from low feed intake, recovery of the gastrointestinal tract after low feed intake is of critical importance.
We have demonstrated that exposure to low feed intake followed by a return to ad libitum feed provision induces ruminal acidosis, even without a dietary change and with low feed intake during recovery. Moreover, the severity of low feed intake affects the recovery responses for dry matter intake and short-chain fatty acid absorption in a dose-dependent manner and exposure to severe low feed intake still results in compromised barrier function extending 21 d after the low feed intake challenge. For situations where low feed intake is predictable (e.g. transportation), The diet fed prior to low feed intake and following low feed intake can affect the severity of the response and rate of recovery. However, for most instances, low feed intake is not predictable or the exact timeline for exposure cannot be accurately predicted. Finally, use of supplements that help support gastrointestinal function may further enhance the recovery response. Thus, it is clear that low feed intake can have negative effects on gastrointestinal function, but there are strategies available to help accelerate recovery of the gastrointestinal tract after a period of low feed intake.