The use of highly digestible corn grain in calf starters when calves are fed an accelerated milk replacer
New corn hybrids have been developed by Masters Choice (MC) seeds that vary in energy density and starch digestibility. These MC hybrids have lower starch densities due to an altered starch structure, which allows for greater ruminal and intestinal starch digestion. Altered starch structure of these new hybrids results in reduced feed manufacturing (i.e. grinding). Thirty (1 to 3 d old) Holstein heifer calves (40.6±1.72 kg) were randomly assigned to 1 of 2 calf starters to evaluate growth performance of Holstein heifer calves through 8 weeks of age. Treatments were: 1) Control (C) starter: containing 40% (DM basis) conventional ground shelled corn and 2) MC starter: containing (40% DM basis) MC corn. Experimental calf starters were formulated to contain 24% CP (DM basis) and were fed for ad libitum consumption as a pellet starting on day 1. The study was conducted from April 25 through August 1, 2013. Body weights and body measurements were collected weekly. All calves were fed a 28% (CP):18% fat accelerated milk replacer 2x/d at the rate of 0.68 kg/d up to 10 days, 1.02 kg/d from 11 to 35 d, and fed 1x/d at 0.51 kg/d from 35 to 42 d. Data were analyzed as a completely random design using the Proc Mixed procedure of SAS Version 9.3. Initial body weights (40.6 and 40.7 kg for C and MC, respectively) were similar (P>0.10), while final body weights (64.5 and 66.7 kg) were numerically greater for calves fed the MC starter. Body weight gains (23.9 and 26.0 kg) and average daily gains (0.68 and 0.74 kg/d) were similar, but numerically greater for calves fed MC starter. No significant differences were detected (P>0.10) in frame parameters as measured by change in body length (12.3 and 11.4 cm), heart girth (8.7 and 9.3 cm), hip height (6.8 and 6.6 cm), and wither height (13.1 and 12.3 cm). While no significance improvements in growth rates were detected in this study, which was conducted during the early summer, but the MC starter resulted in a numerical increase in body weight gains and average daily gains.
Keywords: Corn hybrids, calf starter, starch