Effects of substituting alfalfa hay for concentrate on energy utilization and feeding cost of crossbred Simmental male calves in Gansu Province, China

From August to September 2015 (trial 1 [T1]) and September to November 2015 (trial 2 [T2]), the effects of replacing concentrate feed (C) with alfalfa hay (AH) on the daily gain (DG), dietary energy utilization status and the economic advantage of AH feeding for growing beef cattle were studied in crossbred male Simmental calves (n = 18) in Gansu Province, China. The target DG was set as 1 kg for both trials. Animals in each trial were allocated to a conventional feeding group (CTRL), a low‐level AH feeding group (LA), and a high‐level AH feeding group (HA). In a one‐way‐layout design, they were fed iso‐energetic experimental diets comprising harvested corn stover (CS) and C (T1‐CTRL, T2‐CTRL), diets replacing 22% (T1‐LA) or 44% (T1‐HA) of the quantity of C for T1‐CTRL with AH, and diets replacing 13% (T2‐LA) or 25% (T2‐HA) of the quantity of C for T2‐CTRL with AH. Measurements of feed intake and DG, respiration and metabolism trials were performed for 49 and 41 days in T1 and T2, respectively. Average DG did not reach the target value for HA in T1 and CTRL in T2. Energy metabolizability was slightly greater for CTRL than for LA and HA in T1 and significantly greater for CTRL than for the other groups in T2. There was no marked difference in energy metabolizability between LA and HA in both trials. Dietary substituting AH for C did not impair the feed intake of the animals, but it did not improve feed efficiency. In terms of economic feasibility, low‐level AH inclusion in the diets of growing beef cattle appeared more profitable at the 1‐kg DG level as compared with CTRL and high‐level AH inclusion, and should be practiced in the drylands of Gansu Province, China.