Influence of dietary cation–anion difference in finishing diets fed to Holstein steers during periods of high ambient temperature on feedlot performance and digestive function

ABSTRACTOne hundred twenty-six Holstein steers (457.1 ± 27.5 kg BW) were used in a 127-d experiment to evaluate the influence of dietary cation–anion difference (DCAD) on growth performance and carcass characteristics. Treatments consisted of steam-flaked corn-based diets supplemented to provide DCAD of 34, 84 or 134 mEq/kg diet DM. There was no treatment effect (P > .20) on ADG, DMI, gain efficiency or dietary NE. Six Holstein steers (196 ± 3 kg) with cannulas in rumen and proximal duodenum were used in a replicated 3 × 3 Latin Square design to evaluated treatment effects on digestion characteristics. The DCAD did not affect (P > .20) ruminal or total digestion of OM, NDF, starch and N, or ruminal pH and VFA molar proportions. It is concluded that increasing DCAD of Holstein steers fed a conventional steam-flaked corn-based diet under conditions of high ambient temperature will not enhance growth performance.