Date of this Version
In Proceedings of the American Society of Animal Science Midwest Section, March 19-21, 2012. Des Moines, IA. J. Anim. Sci. 90 (suppl 2): p 80.
A study evaluated using RAMP to adapt cattle to a high grain finishing diet. Yearling crossbred steers (n = 229; BW = 397 ± 28.4 kg) were consecutively weighed over 2 d, stratified by BW, and assigned randomly within strata to 18 feedlot pens, with 12 or 13 steers per pen. Treatments were imposed during grain adaptation (22 d) by decreasing RAMP (100 to 0%) and increasing finishing diet (0 to 100%). RAMP was fed either as a blend in a 1-diet system which was delivered twice daily (RAMP-1RS) or as 2 daily diets where RAMP was delivered in one feeding and finisher was delivered in another feeding (RAMP-2RS). The control treatment (CON) was a traditional adaptation program with alfalfa hay inclusion decreasing (45 to 7.5%) while corn grain inclusion increased. Adaptation steps for RAMP-2RS were 4 d for first diet and 3 d for the 6 subsequent diets, with RAMP delivered as the first feeding during steps 1, 2, and 3 and the finisher as the first feeding during steps 4, 5, 6, and 7. Adaptation steps for RAMP-1RS and CON were 4, 6, 6, and 6 d for steps 1, 2, 3, and 4, respectively. On d 23 through the remainder of the finishing period, cattle were fed a common diet. Treatments RAMP-1RS and RAMP-2RS tended (P < 0.09) to decrease DMI during the adaptation period compared with CON. Daily gain and G:F were similar (P > 0.50) among treatments during the grain adaptation period. Over the entire feeding period RAMP-1RS and RAMP-2RS increased (P < 0.01) G:F compared with cattle adapted using CON (0.142, 0.141, and 0.131, respectively). Feeding RAMP-1RS increased ADG (P = 0.03) compared with CON. Intakes were similar (P = 0.39) among treatments. Feeding RAMP tended to increase (P = 0.13) HCW, no other carcass traits were affected (P > 0.4) by adaptation method. Using RAMP is a viable alternative to traditional adaptation and led to improved feed efficiency in this study regardless of whether it was delivered with the finishing diet as a blend or in 2 daily diets.