Associations Between Feeding Behaviors, Residual Feed Intake, and Residual Average Daily Gain in Performance Tested Yearling Bulls and Heifers Fed a High-Forage Diet

Variation in individual animal feed intake is influenced by factors such as bunk management, digestive physiology, social hierarchy, and health status. While previous research has primarily examined feeding behavior in cattle offered high-concentrate diets, limited information exists regarding these relationships in high-forage systems. Residual Feed Intake (RFI), defined as the difference between an animal's actual and expected feed intake based on metabolic mid-test body weight and average daily gain, serves as a key measure of feed efficiency. Animals with negative RFI values are classified as more efficient, whereas those with positive values are less efficient. This study investigated associations between feeding behavior and feed efficiency in yearling purebred Angus bulls (<i>n</i> = 232) and heifers (<i>n</i> = 58) consuming forage-based diets using a Vytelle feeding system. Upon arrival, bulls averaged 350.3 ± 3.6 kg and heifers averaged 287.5 ± 5.0 kg, with a subsequent 14-day acclimation followed by a 49-day ad libitum feeding period. In bulls, RFI was positively correlated with bunk visits (r = 0.34, <i>p</i> < 0.0001) and negatively correlated with duration (r = -0.16, <i>p</i> = 0.0124). In heifers, daily visits were negatively correlated with intake (r = -0.88, <i>p</i> < 0.0001), and RFI was negatively associated with RADG (r = -0.53, <i>p</i> < 0.0001).