Mortality on grower/finisher-only swine operations in the United States

For 53 grower/finisher-only swine operations that participated in the United States National Animal Health Monitoring System 1995 National Swine Study, mortality among finisher pigs ranged from 0 to 12.0% over a 6-month period. Twenty-six (49.1%) had <2% mortality, and 27 (50.9%) had >2% mortality. Nine (17.0%) operations experienced >4% mortality. Fisher's exact test revealed that operations with all-in all-out management were significantly more likely to have <2% mortality than operations with continuous management, and that operations where all finisher pigs came from farrowing units belonging to the operation (either on-site or off-site) were significantly more likely to have <2% mortality than operations where >1 grower/finisher pig came from another source. Larger operations (where >900 pigs entered the grower/finisher phase) practiced all-in, all-out management more frequently than smaller operations, and had a lower mean percent mortality than smaller operations. Diagnosis of Salmonella in finisher pigs performed at a laboratory or by a veterinarian in the 12 months prior to interview was associated with both increased percent mortality and increased percent mortality per day. A mortalidade de suínos, durante um período de 6 meses, variou de 0 a 12% em 53 granjas de crescimento/terminação, que participam do "United States National Animal Health Monitoring System 1995 National Swine Study". Vinte e seis (49,1%) granjas tiveram <2% de mortalidade e 27 (50,9%) tiveram índices >2%. Nove (17,0%) granjas apresentaram mortalidade >4%. A análise pelo teste de Fisher revelou que as granjas que adotavam o sistema "all-in, all-out" eram significativamente mais propensas a apresentar índices <2% que as granjas com manejo contínuo, e que as granjas nas quais todos os suínos terminados eram oriundos de unidades pertencentes às próprias granjas eram significativamente mais propensas a ter mortalidade <2% que as granjas onde os animais (>1) provinham de outras origens. Granjas maiores (com mais de 900 animais entrando na fase de crescimento/terminação) adotavam com maior freqüência o manejo "all-in, all-out e tiveram menor percentual de mortalidade do que pequenas granjas. O diagnóstico de Salmonella em suínos terminados, realizado 12 meses antes da intervenção, foi associado ao aumento do percentual de mortalidade geral e diário