Spectral analysis of feeding patterns of steers divergent in residual feed intake

Spectral analysis was used to quantify differences in feeding patterns of Angus steers genetically divergent in residual feed intake (RFI). Forty- two low RFI (more efficient) and 28 high RFI (less efficient) selection line steers were fed a feedlot diet through electronic feeders for 72 days. Mean (+/- s. e.) daily feed intake was 11.9 +/- 0.076 and 12.7 +/- 0.095 kg dry matter/ day over the 72- day feeding period for low and high RFI steers, respectively. The high RFI steers exhibited different temporal cycles to the low RFI steers in daily feed intake and time spent feeding. However, patterns of number of eating sessions, feeding rate, the time spent eating and the number of eating sessions were similar. Further analysis of daily (24 h) feeding behaviour is required to help improve our understanding of the association between feeding behaviour and feed efficiency.