Phenotypic and genetic correlations between feeding behaviours and feed efficiency in crossbred beef replacement females

The objectives of this study were to identify the phenotypic and genetic relationships and heritability (h(2)) of feeding behaviours (FB) in replacement beef females. Between 2005 and 2017, heifers (N = 1394) were tested for feed intake using an electronic feed bunk system. The various FB were feeding duration (DUR; min d(-1)), head down time (HD; min d(-1)), feeding frequency (FREQ; events d(-1)), time-to-bunk (TTB; min). Dry matter intake (DMI; kg d(-1)), and residual feed intake adjusted for off-test ultrasound back fat thickness (RFIFAT) were also reported. The h(2) estimates for DUR, HD, FREQ, TTB, DMI, and RFIFAT were 0.25 +/- 0.05, 0.26 +/- 0.06, 0.27 +/- 0.05, 0.29 +/- 0.06, 0.26 +/- 0.05, and 0.40 +/- 0.07, respectively. These are the first h(2) to be presented for these FB among developing replacement heifers on a high-forage diet.