Retrospective evaluation of animal mortality in US feedlots

Feedlot closeout records from January 2005 through September 2014 were summarized. A total of 484,193 lots involving 73,067,534 cattle were used to illustrate mortality. Mortality rate and average days-on-feed at death by placement weight, sex, and cause of death (respiratory, digestive, and acute interstitial pneumonia) were calculated from these records. Mortality averaged 1.56 and 1.43% in heifers and steers, respectively. Mortality trends were seasonal; respiratory mortality was highest in late fall and early winter, digestive mortality was highest in late spring, and AIP mortality was greatest during summer months. Mortality during the first 30 days of the feeding period averaged 0.40% and 0.35% for heifers and steers, respectively. Mortality in the mid-portion of the feeding period, the last 31 to 60 days, and the last 30 days of feed averaged 0.70%, 0.20%, and 0.26% for heifers and 0.70%, 0.18%, and 0.21% for steers, respectively. These data suggest animal mortality is not isolated to the receiving period and occurs at comparable rates thereafter.