The impact of bovine respiratory disease: the current feedlot experience.

Mortality during the finishing phase in beef steers has increased over the last 13 years at a rate of 0.05% per year for cattle fed in Cactus Feeders' operations. A change in the demographics of placements has also occurred, in that heavier weight cattle are being placed as compared to previous years. Morbidity rates are lower, but higher case fatality rates are observed when compared to years when lighter weight cattle were placed. More lung lesions of varying degree are documented at necropsy of new arrivals and there is greater perception of reduced response to therapy in animals identified with respiratory disease. As placement weights have increased, mortality in the early stages of the feeding period has decreased, resulting in a greater proportion of total death loss later in the period. This shift, in conjunction with an increasing long-term trend of total death loss, can lead to the interpretation of higher 'late day mortality'. Rather than relying solely on observation and distributions of the data, Cactus Feeders believes that the development of a predictive model is better suited to address the potential of 'late day mortality' in confined cattle feeding operations.