Influence of roughage and grain processing in high-concentrate diets on the performance of long-fed Holstein steers.
Traxler M.J. | Fox D.G. | Perry T.C. | Dickerson R.L. | Williams D.L.
The effects of roughage source and timing of inclusion in high-concentrate diets on feedlot performance were evaluated in each of 2 yr with 144 and 120 long-fed Holstein steers, respectively. Roughage, when included in the diet, was delivered in a built-in-roughage (BIR) pellet supplying 15 and 6% roughage (percentage of DM) or hay crop silage (HCS) supplying 7 and 10% roughage (percentage of DM) for the growing and finishing periods, respectively. The six dietary treatments (two pens each) investigated were continuous whole corn and pelleted supplement (no added roughage; WSC-PEL); BIR with cracked corn either in the growing (BIR-G) or finishing (BIR-F) period with whole corn being fed with pelleted supplement when BIR was not part of the diet; BIR and cracked corn fed continuously (BIRCONT); and two HCS treatments in which the corn was fed either whole (HCS-WSC) or cracked (HCSCSC) for the entire feeding period. Replicates were slaughtered 4 and 3 wk apart for yr 1 and 2, respectively. Pooled daily gains (yr 1 and 2) for the entire trial (1.39 to 1.45 kg/d) were not different (P > 0.05). Daily DM and concentrate intakes were lower (P < 0.001) and gain efficiency was higher (P < 0.001) for the WSC-PEL than for the other treatments. Carcass characteristics were similar among treatments except for an improved yield grade (P < 0.02) for the HCS treatments over the BIR treatments. The WSC-PEL treatment was the most profitable ($/steer) and the BIR-CONT diet was the least profitable. The HCS treatments were the most profitable of the roughage treatments. A newly proposed intake prediction equation for feedlot cattle performed similarly to the 1984 NRC equation with long-fed Holstein steer calves.
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