Abstract
The objective of this research was to test the role of limiting forage and butyrate supplementation in pre-weaned calves on the incidence of sub-acute ruminal acidosis during the weaning transition. For study 1, mean ruminal pH had a tendency to be lower in limit-fed calves and duration and severity of sub-acute ruminal acidosis were higher in calves limit-fed forage. In study 2, there were no differences in average daily gain, blood plasma glucose or β-hydroxy-butyrate concentrations, or ruminal pH between pre-weaning dietary treatments. For post-weaning calves, calves fed a butyrate supplemented starter tended to have higher starter intake and average daily gain, but lower mean ruminal pH, leading to longer duration of sub–acute ruminal acidosis. Based on these data, limiting forage intake prior to weaning increases sub-acute ruminal acidosis while supplementing butyrate during the weaning transition increases feed intake, weight gain, and sub-acute ruminal acidosis immediately after weaning.