| Holstein calves (225) were fed texturized calf starters, from 2 to 42 d of age, containing 0 (C), 1% (1YC), or 2% (2YC) yeast culture (Experiment 1); 5% (5M) or 12% (12M) molasses (Experiment 2); or whole ( WC), dry-rolled (DRC), roasted-rolled ( RC), or steam-flaked (SFC) corn (Experiment 3) were offered to dairy calves to determine dietary alteration effects on intake, growth, blood and rumen metabolites, and rumen development.;Calves receiving 2YC had significantly higher starter and total dry matter intake (DMI), average daily gain (ADG), and daily hip width change than C calves. Dally hip height change was significantly greater for 2YC than 1YC calves. These data suggest that starter containing 2% yeast culture enhances DMI, growth, and slightly improves rumen development in dairy calves.;Post-weaning and overall starter DMI, overall total DMI, daily heart girth change, and final heart girth were significantly lower in 12M than 5M calves. However, blood volatile fatty acid (VFA) concentrations were significantly higher in 12M than 5M calves. When starter contained 12% molasses calf intake and structural growth decreased, possibly causing decreased weight gain, but blood VFA concentrations and rumen development increased.;Post-weaning and overall starter and total DMI were significantly higher in DRC than RC or SFC calves. Post-weaning starter and overall starter and total DMI were significantly higher in WC than SFC calves. Post-weaning ADG was significantly greater in DRC than SFC calves. Daily structural growth was greatest in RC calves. Blood VFA concentrations were significantly higher in SFC calves than in calves fed other treatments. Papillae length and rumen wall thickness was significantly greater in SFC calves than in DRC and WC calves, respectively. Rumen pH was higher and rumen VFA concentrations lower in WC calves than in other treatments. Rumen propionate production was increased in SFC calves. Rumen butyrate production was higher in RC calves. Results indicate that corn processing method influences intake, growth, and rumen parameters in calves. Calves consuming RC starter had similar ADG, feed efficiency, and rumen development but increased structural growth and ruminal butyrate production when compared to the other three corn processing treatments. |
