A study on feeding ammoniated and processed barley to feedlot steers

A total of 120 commercial crossbred steer calves (284±1.9 kg) were allocated in a 2×2 arrangement to two barley processing methods; whole (W) or rolled (R) barley and two ammoniation treatments; ammoniated (A) or non-ammoniated (N) barley. Steers were randomly allocated to twelve pens with 10 steers per pen and 3 pens (replications) per diet. The study was divided into two stages, growing (0–84 day) and finishing (85–196 day). Average daily gain (ADG) for the overall 196 day period was affected by processing (p<0.01) averaging 1.10 and 1.20 kg day−1 for steers on W and R barley, respectively. Steers on the R barley gained 19.6% more than those on W barley during the growing stage and 0.8% more during the finishing stage. There was a trend towards an improvement (p=0.06) in overall ADG by ammoniation. The ADG of steers was significantly higher (p<0.01) during the finishing (1.22 kg day−1) than during the growing (1.06 kg day−1) stage. Feed efficiency was better with R than with W barley (6.8 vs. 7.7; p=0.02). Processing and ammoniation had no effect (p>0.05) on carcass traits or grades.