Epidemiology, economic losses, and management implications associated with pneumonia-related mortality in feedlots from Brazil1

Epidemiologia, perdas econômicas e implicações de manejo associadas a mortalidade relacionada à pneumonia em confinamentos no Brasil

Cattle death due to pneumonia-related mortalities (PRM) is a major problem in beef cattle feedlots worldwide. However, compared to other major beef-producing countries, Brazil lacks sufficient data on these losses, having no information to define the optimal feeding duration for cattle. This study investigated PRM at three beef cattle feedlots in the major cattle production states of Brazil over a 24-month period. PRM was the second cause of cattle mortality at these feedlots and accounted for 20.2% (142/703) of all mortalities. Nelore cattle had higher chances (OR = 1.79, p= 0.006) to develop PRM as compared with crossbreed animals, while cattle maintained in feedlots from Mato Grosso were at elevated risk (OR = 1.74, p = 0.031) to develop PRM relative to those maintained in the feedlots from Minas Gerais. Logistic regression revealed that PRM risk decreased with time on feed, confirming that PRM are more likely (p= 0.0005) to be elevated during the earlier days of cattle on-feed at these feedlots. The occurrence of PRM was not influenced by the sex (p= 0.653) of the animal affected nor seasonal variations (p = 0.653). The estimated annual cost of PRM at these feedlots was 105,027 USD, with a projected national cost of 4.040 M USD. A statistical model projected that it may be profitable to maintain cattle in these feedlots for approximately 120-130 days, after which financial investment declines. These results demonstrate the importance of PRM to the local beef cattle industry and emphasize the need to investigate other factors that may influence reduced productivity in beef cattle feedlots in Brazil.

INDEX TERMS:
Bovine respiratory disease; economic impacts; feedlot economics; lung pathology; statistical modeling