Use of a complete-feed diet (RAMP) to rapidly transition cattle to a finishing diet

A study evaluated transitioning cattle from RAMP to a finishing diet with fewer intermediate step diets and days fed during transition. Yearling crossbred steers (n = 390; BW = 341 ± 14 kg) were blocked and stratified by BW, and assigned randomly within strata to 40 feedlot pens, with 9 or 10 steers per pen. Treatments were different grain adaptation programs (27 or 28 d) involving blends of RAMP and finishing diet. A control adaptation program involved decreasing RAMP and increasing a 62.5% corn finishing diet (62.5% high moisture corn (HMC), 25% sweet bran, 7.5% alfalfa hay (AH), and 5% dry supplement) in 5 steps (100:0, 75:25, 50:50, 25:75, and 0:100 RAMP to finishing diet) fed for 4, 6, 6, 6, and 6 d, respectfully (CON62.5). Four remaining adaptation programs involved decreasing RAMP and increasing inclusion of a 40% corn finishing diet (40% HMC, 47.5% sweet bran, 7.5% AH, and 5% dry supplement). Two programs consisted of 5 steps (100:0, 75:25, 50:50, 25:75, and 0:100 RAMP to finishing diet), fed for either 4, 6, 6, 6, and 6 d (CON40) or 10, 1, 1, 1 and 14 d (3–1d), The final 2 programs consisted of 4-steps (100:0, 67:32, 32:67 and 0:100 RAMP to finishing diet) fed for 10, 2, 2, 14 d (2–2d) or 3-steps (100:0, 50:50, and 0:100 RAMP to finishing diet) fed for 10, 4, and 14 d (1–4d). Following adaptation, a common finishing diet (40% HMC, 25% sweet bran, 22.5% modified distillers grains with solubles, 7.5% AH, and 5% dry supplement) was fed for the remainder of the feeding period. Adaptation program did not affect DMI (P \u3e 0.2) during the adaptation period or over the entire feeding period. Daily gain and G:F were similar (P \u3e 0.7) among treatments with G:F of 0.179, 0.182, 0.179, 0.182, 0.181 for CON62.5, CON40, 3–1d, 2–2d, and 1–4d, respectively. Carcass traits were not affected (P \u3e 0.1) by adaptation method. Cattle started on RAMP can transition to a finishing ration containing 47.5% sweet bran in fewer days with fewer step diets than traditional grain adaptation programs without negatively affecting performance