Effects of beef calf health status during receiving on subsequent performance during stocker and finishing phases of production*

Objective

The objective of this analysis was to de- termine the effects of purchasing cattle as steers or bulls and bovine respiratory disease (BRD) treatment of stocker calves during receiving on performance during subsequent stages of production.

Materials and Methods

This post hoc analysis used mixed steer and bull calves with full health data records (n = 1,965) from 9 experiments, steer calves with receiv- ing health data and subsequent grazing performance data (n = 2,032) from 10 experiments, and steer calves with receiving health data with subsequent grazing and fin- ishing performance data (n = 423) from 2 experiments. Data were analyzed as random effects or generalized linear mixed models with experiment as the random effect in the R software.

Results and Discussion

Calves received as intact bulls (n = 1,064) were 2.41-, 2.25-, 2.68-, or 2.94-times more likely to have a first, second, third, and fourth treat- ment, respectively, than calves that were received as steers (n = 901). Bulls were also 1.16-times more likely to have chronic morbidity and 2.27-times more likely to have BRD mortality than steers. As the number of BRD treatments increased, ADG during receiving decreased. This carried over for reduced BW during turnout on pasture and at the end of grazing. When steers were followed through finishing, increased number of BRD treatments during the stocker receiving period reduced BW at slaughter, hot car- cass weight, and marbling and increased the number of days on feed to achieve a calculated 28% empty body fat carcass (based on equations by Guiroy et al., 2001).

Implications and Applications

Bovine respiratory disease has long-term implications on performance, not only during the receiving period but also on BW and productivity following the stocker grazing phase and fin- ishing. We observed no compensatory gain on pasture or during finishing from reduced performance due to health issues in the receiving phase. Increased BRD morbidity and less favorable health outcomes for calves arriving as intact bulls would require at least a $0.50/kg discount for intact bulls for equivalent net returns to steers.