PSVII-19 - Feeding Behavior of Feedlot Beef Steers Consuming Finishing Diets with an Added Nutritional Packet

Abstract: The effects of a nutritional packet offered to beef yearling-steers during the feedlot-finishing phase on feeding behavior were evaluated. Crossbred-Angus steers (n = 30; initial BW = 542 ± 8 kg) were assigned to pens (15 steers/pen; animal = experimental unit) in a randomized complete block design. Steers were offered a steam-flaked corn-based finishing diet ad libitum, and treatments as follows: 1) control and 2) 30 g/steer-daily (DM-basis) of a nutritional packet (live yeast [Saccharomyces cerevisiae; 8.7 Log CFU/g], vitamin C [5.4 g/kg], vitamin B1 [13.33 g/kg], NaCl [80 g/kg], and KCl [80 g/kg]). Ground corn was used as a carrier and included at 1% of diet DM. Orts were subtracted from the dietary DM offered to calculate DM intake. Feeding behavior (meal frequency, meal size, bunk visit duration, and meal criterion) were continuously recorded using the Smartfeed system (individual animals). Three periods during the last 60 days before cattle harvest were assessed: 1) d7-11; 2) d28 -32; and 3) d49-53. Periods were used to compute meal criteria for each animal using the Meal Criterion Calculation (v. 1.9) software. Data were analyzed using the GLIMMIX procedure of SAS. No treatment × period interactions were observed (P ≥ 0.32) for meal frequency, duration (min/meal), and intake (kg/meal). Steers offered the nutritional packet had greater overall meal duration during periods 1 and 3 (75 and 77 min/d; P < 0.01), but did not differ (68 min/d; P = 0.09) for period 2 (Control AVR = 55 min/d). Steers offered the nutritional packet had greater (P ≤ 0.01) meal frequency (20 vs. 16 meals/d), while individual meal duration (3.85 min/meal) and meal intake (0.46 kg/meal) were not affected by treatments (P > 0.86). Improved meal frequency and overall time spent eating, without affecting intake, may induce a more desirable daily distribution of nutrients.