Abstract
Heat stress (HS) can be a significant source of risk for Midwestern cattle feeders. Feedlot managers (n = 46) from South Dakota, Minnesota, and Nebraska were surveyed regarding facilities, HS mitigation strategies, perceived success or failure, and strategies they would like to employ. Open yards (OY) were the most common system (62.5%), followed by total confinement (TC; 23.4%) and partial confinement (PC; 14.1%) with 15 respondents (32.6%) reporting multiple systems. Adjusting feed deliveries and introducing feed additives to mitigate HS were utilized by 32.6% and 34.8% of respondents, respectively. Environmental modifications were made to all OY (90% water application, 55% shades, and 25% bedding). Among respondents managing TC or PC facilities, in addition to the shade provided by buildings themselves 12.5% applied water during emergencies and 8.3% utilized fans. Cattle handling during heat events was scheduled to minimize HS by 100% of surveyed feedlots. During HS events, 67.4% adjusted shipping schedules and 32.6% provided additional water supply. Initiation of mitigation strategies were triggered by observed weather conditions (56.5%), indicators of cattle stress (39.1%), HS alerts (26.1%), and the calendar (6.5%). Shade-providing structures (TC, PC, or OY shades) were perceived as the most successful environmental modification (60.9%) followed by water application (50%), extra water supply (32.6%), and bedding (23.9%). Strategies perceived as less successful included water application (23.9%), feed additives (21.7%), and bedding (17.4%). Increased mud was specifically cited by 63.6% of respondents dissatisfied with water application. Respondents indicated providing more shade structures (63%) and confinement buildings (17.4%) for HS mitigation would be beneficial, but primary barriers were cost, time, and not a yet critical need (71.7, 21.7, and 10.9%, respectively). Midwest cattle feeders use many strategies specific to their needs to mitigate HS with those reducing solar load perceived as the most successful.
Evaluating joint operation rules for connecting tunnels between two multipurpose dams
