Effect of oscillating feeding time and corn processing on performance and carcass characteristics of feedlot steers.

The objectives of this experiment were to evaluate the effect of oscillating feeding time (OFT) and corn processing (CoP) on performance and carcass characteristics of feedlot cattle. One hundred sixty-five steers (initial body weight [BW] 277.2 ± 27.80 kg) were blocked by initial BW and allotted to 24 pens. Pens within each block were randomly assigned based on a 2 × 2 factorial arrangement of treatments. The two factors were CoP (whole shelled corn vs. ground corn [GC]) and feeding time (FT) (constant FT vs. 2 hours OFT). Animals were fed the same diet, only changing the CoP method depending on the treatment. Feed offered and feed refusals were collected daily. Body weight was collected at starting day of the experiment (d1) and every 28 d until the end of the experiment. At the end of the experiment, animals were harvested in a commercial slaughter facility, and carcass data were collected by a USDA grader. Animal growth performance and carcass characteristics data were analyzed with the PROC Mixed procedure (SAS) using CoP, FT, and their interaction as fixed variables; and treatments × pen within each block and block were considered random variables. There was no CoP by FT interaction differences (P > 0.10) on animal growth performance variables, nor on hot carcass weight, back fat, rib eye area, or the percentage of kidney, pelvic, and heart fat. There was a tendency for an interaction (P = 0.08) for marbling score, where the steers from the GC processing fed on the oscillating time had a lesser marbling score than the other three treatments. Oscillating feeding time improved (P = 0.05) average daily gain; but did not affect (P ≥ 0.11) dry matter intake (DMI), nor carcass characteristics compared with feeding at a similar time every day. There were no effects (P ≥ 0.11) of CoP on growth performance, nor carcass characteristics. In conclusion, a 2-hour oscillation in FT might not decrease steer feedlot performance. This may be due to the high degree of control of DMI with feed bunk management.