| dc.description.abstract | Angus crossbred steers from two genetically similar sources (n = 48 BCS and n = 48 McG), were transported separately (833.64 ± 85.29 km) 39-d prior to commingling and housed at a feedlot without visual or tactile contact. Steers, blocked by source and d -34 body weight, were randomly assigned to 12 pens (n = 8 steers/pen). Pens housed either: NOMIX—100% from BCS (n=3 pens) or McG (n=3 pens) or MIX—50% from BCS and 50% from McG (n = 6 pens). Video recordings were decoded on d 0, 1, and 2 for the number of agonistic behaviors, allogrooming bouts, and drinking bouts initiated by each steer during the first four hours post-mixing. Rumination behavior was recorded on d 1, 2, and 3 post mixing. Mixed models evaluated the impact of treatment, day, and their interaction on cattle behavior. Orthogonal contrasts compared the impact of source on performance of each behavior and Pearson correlations were used to compare total performance of each behavior throughout the study. NOMIX steers performed more (P = 0.08) drinking bouts (10.54 ± 1.27 bouts/steer/pen) than MIX steers (7.68 ± 1.05 bouts/steer/pen). Steers ruminated less on d 3 (NOMIX: 7.97 ± 0.29 hours/steer/day MIX: 8.06 ± 0.29 h/steer/d) than on d 1 (NOMIX: 8.55 ± 0.29 h/steer/d MIX: 8.22 ± 0.29 h/steer/d) or d 2 (NOMIX: 8.77 ± 0.29 h/steer/d MIX: 8.46 ± 0.29 h/steer/d) across all treatments. Steers in MIX pens (7.81±0.30 h/steer/d) spent more time ruminating than steers in NOMIX pens from McG (7.46±0.47 h/steer/d) than steers in NOMIX pens from BCS (8.39±0.52 h/steer/d). NOMIX pens initiated more (P < 0.01) headbutts overall (1.98 0.13 count/steer/pen) and mounts on d 2 (1.07 0.11 count/steer/pen) than those in MIX pens (1.30 0.18 and 0.39 0.15, respectively). Social mixing reduced agonistic behavior and may cause cattle to take longer to establish social hierarchies. Social mixing also decreases drinking behavior and delays social hierarchy establishment. | |
