The aim of this study was to evaluate the effects of dietary inclusion of palm kernel cake (PKC) on the feeding behavior of feedlot-finished cattle. Forty uncastrated crossbred bulls with an average age of 24.2 ± 2 months and an average weight of 331.1 ± 36.2 kg were distributed into four treatment groups in a completely randomized design with ten replicates. The treatments consisted of 0, 8, 16, or 24% PKC inclusion in the diet (dry matter basis). Palm kernel cake inclusion influenced feeding time (P < 0.05), which increased linearly. The inclusion of the ingredient also affected (P < 0.05) rumination time (min/day), total chewing time, and the time spent on other activities. The number of cuds ruminated per day showed a linear response to the PKC inclusion levels (P < 0.05). The number of feeding bouts increased linearly (P < 0.05). Dry matter (DM) intake and DM feeding efficiency decreased linearly (P < 0.05). There were no effects of PKC inclusion (P > 0.05) on neutral detergent fiber feeding (NDF) efficiency or DM rumination efficiency. NDF rumination efficiency increased linearly (P < 0.05). Palm kernel cake can be included at levels up to 24% in the total diet of feedlot-finished crossbred bulls, as it does not affect their dry matter intake or feeding behavior.
Keywords: Efficiency; Ethology; Ingestion; Ruminant.