Feeding behaviour and activity of beef calves during the first week at the feedlot: Impact of calf source and commingling ratios

Preconditioned (PC) calves have reduced morbidity, mortality and improved performance compared to auctionderived (AD) and non-preconditioned calves; however, there is limited research on the impacts of commingling PC and AD calves at the feedlot. Commingling calves from various sources is known to be highly stressful and can impact performance on arrival at the feedlot. Therefore, the first objective was to assess feeding behaviour (time spent eating and ruminating) and activity of PC beef calves during the first 7 days after arrival at the feedlot compared to ranch-sourced (RS) and AD calves. The second objective was to assess the impacts of commingling PC calves with various proportions of AD calves (25, 50, 75 %) on feeding behaviour and activity in that same time frame. A subset of 45 calves per pen for PC, AD, and commingled pens, and 20 RS calves were equipped with CowManager (R) tags on arrival. This technology detects ear movement through a sensor in the tag linked to eating, ruminating, active and not active. On average, in the first 7 days at the feedlot, PC calves spent 11 % more time eating than RS and 15 % more time than AD calves. PC calves spent 5 % less time active compared to RS (P < 0.000), and there was no significant difference in activity compared to AD. PC calves spent 4 % less time not active compared to RS (P = 0.017) and 15 % less time inactive compared to AD calves (P < 0.001). There was no difference among PC, RS and AD in overall time spent ruminating. When comparing PC calves from 100 % PC and commingled pens, 100 % PC calves spent 5 % more time eating compared to a 75 % ratio PC and 5 % more time eating compared to a 25 % ratio PC pen. However, time spent eating was not significantly different between 100 % PC and 50 % ratio PC. Furthermore, PC calves had increased time spent eating and less time spent active and not active during the first 7 days after arrival at the feedlot compared to RS and AD calves. When commingled with AD calves, PC calves had more time spent eating and reduced time spent active and not active; therefore, PC calves have exhibited increased feeding behaviour also after being commingled with AD calves at the feedlot. The current study acknowledges the limitations of the field experiment that not all confounding variables could be controlled for, explicitly pen effect due to the lack of replication of pens across groups.

Automated summary

Commingling of preconditioned and auction-derived calves has an impact on feeding behavior and activity. Preconditioned calves have longer eating time and shorter active time compared to ranch-sourced and auction-derived calves. When commingled with auction-derived calves, preconditioned calves exhibit improved feeding behavior and activity.