Effects of feeding dry-rolled corn or whole shelled corn on feedlot performance, carcass characteristics, and eating behavior of finishing Holstein steers

Abstract

The objective was to determine the effect of corn processing method on feedlot growth performance, carcass characteristics, estimated starch digestibility, and eating behavior of Holstein steers fed a corn-based diet. Seventy-nine Holstein steers (average initial BW = 451 ± 6 kg) were assigned randomly to 1 of 2 treatments: (1) whole shelled corn (WSC) or (2) dry-rolled corn (DRC). Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). No effect ( P ≥ 0.55) of treatment on final BW was detected. No differences ( P ≥ 0.18) in ADG, DMI, or G:F were detected. However, Holstein steers fed DRC had 28% less ( P ≤ 0.01) fecal starch and an 8% greater ( P ≤ 0.01) estimated total-tract starch digestibility when compared with those fed WSC. In addition, Holstein steers fed WSC ate 10% fewer ( P < 0.01) meals that were 10% larger ( P < 0.01) and took 17% longer ( P < 0.01) to eat than those fed DRC. Corn processing method failed to significantly alter ( P ≥ 0.19) hot carcass weight, DP, marbling, or QG of the carcass. However, steers fed WSC had a greater ( P ≤ 0.01) LM area and less ( P ≤ 0.05) s.c. fat thickness, calculated YG, and calculated empty body fat at slaughter. Despite the increased fecal starch and decreased estimated starch digestibility, feeding the WSC-based diet to finishing Holstein steers did not alter feedlot growth performance or hot carcass weight when compared with feeding the DRC-based diet. Therefore, feeding WSC may be an alternative for beef cattle producers who cannot afford to process corn for the diets of finishing animals.