CASE STUDY: Effect of truck compartment on ruminal temperature during transit and subsequent health and performance of recently weaned beef heifers

This experiment evaluated how truck compartment affects ruminal temperature (Trum) during transit, subsequent performance and morbidity, and whether Trum during transit can predict subsequent health and performance. Four truckloads of heifers (n = 328) were used. Compartments included bottom deck nose, middle, and rear and upper deck nose, middle, and rear. Main effects included level and section. There was a level × section interaction (P < 0.01) for Trum. For bottom-deck heifers, Trum was greatest (P < 0.05) in the nose, and Trum of upper-deck heifers was greatest (P < 0.05) in the middle. Heifers in the upper deck rear had the lowest Trum (P < 0.05). From d 0 to 14 after arrival, there was a level × section interaction (P = 0.02) for ADG. Among upper-deck heifers, those in the nose gained 0.63 kg/d less (P < 0.05) than did those in the middle. Section did not affect ADG for heifers in the bottom deck (P > 0.10). There were level × section interactions (P ≤ 0.02) for morbidity measurements. Within the first 14 d, a greater (P ≤ 0.05) percentage of heifers in the bottom deck nose and upper deck rear were treated for respiratory disease compared with those in the bottom deck rear and upper deck nose. Regression analysis did not suggest a relationship (P ≥ 0.12) between Trum during transit and subsequent health. Treatment frequency and Trum are affected by compartment during transit. Heifers transported in the bottom deck nose had higher Trum during transit and increased subsequent respiratory disease incidence.