Comparison of alternative backgrounding systems on beef calf performance, feedlot finishing performance, carcass traits, and system cost of gain

Abstract

A 3-yr experiment was conducted to evaluate the effects of swath grazing forage barley (Hordeum vulgare; cv. Ranger) or foxtail millet (Setaria italica; cv. Golden German) compared with grass-legume hay fed in drylot pens on beef calf performance during backgrounding and finishing phases. Annually, 120 spring-born Angus-cross stocker calves (60 steers, 60 heifers; BW = 227.6 ± 3.5 kg) were randomly allocated to 1 of 3 replicated (n = 2) backgrounding (BG) systems. Backgrounding systems were 1) swathed barley grazing (BAR), 2) swathed millet grazing (MILL), and 3) ground hay bunk fed in drylot (DL). All calves were supplemented with a 16% CP range pellet (2.5 kg/d). Swath-grazed calves were limit grazed using electric fencing in 4-ha paddocks with a 3-d grazing period for 96 d each year. Following BG, calves were placed in a feedlot, separated by BG treatment, and fed a similar finishing diet for 155 d and harvested at a targeted endpoint of 12 mm of rib fat. Forage samples were collected every 21 d and analyzed for DM, CP, and DE. Digestible energy content was greatest (P < 0.05) for swathed barley (10.0 MJ/ kg) and lowest for DL hay (8.4 MJ/kg). Stocker ADG during BG was greatest (P < 0.05) for BAR (0.8 kg/d) compared with MILL (0.6 kg/d), and DMI of BAR calves (7.8 kg/d) was numerically greater (P = 0.32) than MILL (6.8 kg/d) or DL calves (7.5 kg/d). Cost of gain for the BAR system ($1.70/kg) was 31% less (P < 0.05) compared with the MILL ($2.45/kg) or DL ($2.47/kg) system, suggesting swath grazing whole plant barley with beef calves may be more cost effective. There were no differences (P > 0.05) in final feedlot BW, total feedlot ADG, rib or rump fat, carcass characteristics, or feedlot cost of gain of calves from the 3 backgrounding systems. This experiment indicates that backgrounding calves on swathed barley or millet in field paddocks will not adversely affect feedlot performance or carcass characteristics compared with backgrounding calves in a traditional DL system.