Associations between the distance traveled from sale barns to commercial feedlots in the United States and overall performance, risk of respiratory disease, and cumulative mortality in feeder cattle during 1997 to 20091

Abstract

Most beef cattle are transported at least once during their lives, and this potentially stressful practice may affect subsequent health and performance. Limited research is available quantifying the effects of transport on feedlot performance and health, and particularly the risk of bovine respiratory disease complex (BRD), which is the most common disease of weaned calves after arrival to the feedlot. The objective of this retrospective study was to determine potential associations between distance traveled (DTV) during transportation with health (cumulative BRD morbidity and mortality of all causes) and performance (ADG and HCW) parameters in cattle cohorts (n = 14,601) that arrived to 21 U.S. commercial feedlots from 1997 to 2009. Multivariable mixed-effects negative binomial and linear regression models were employed to determine associations between health and performance outcomes with DTV and other cohort-level demographic variables. Cattle were transported a median of 552 km from origin to feedlot with a mean (± SEM) of 698 ± 4.4 km. The mean (±SEM) cumulative BRD morbidity was 4.9% ± 0.01% (median = 1.1%; range: 0 to 100%) whereas the mean (±SEM) cumulative mortality due to all causes was 1.3% ± 0.01% (median = 0.8%; range: 0 to 28.7%). Distance traveled was significantly associated (P < 0.05) with BRD morbidity, overall mortality, HCW and ADG, and its effects were modified by demographic characteristics (i.e., cohort region of origin, mean arrival BW, gender, and the season of the year) of the cohort. Knowledge of the distance traveled during transportation could allow a more precise prediction of cattle feedlot health and performance.

Associations between animal characteristic and environmental risk factors and bovine respiratory disease in Australian feedlot cattle

“…In cohort-level studies, mixed-sex cohorts were at increased risk compared to single-sex cohorts (Sanderson et al, 2008) and all-male cohorts were at increased risk compared to all-heifer cohorts (Cernicchiaro et al, 2012b). In our study, heifer-only and mixed-sex cohorts were restricted to a small number of feedlots and clustered by feedlot; estimates of effect were imprecise so we cannot draw a conclusion about effects of the sex of the cohort on BRD risk.…”

“…Similarly, North American studies have identified variation in risk depending on feedlot location (Cernicchiaro et al, 2012b). Feedlot region is likely to be a proxy for many risk factors, including unknown or unmeasured factors, so that much of the effect would be expected to be indirect.…”

“…Source region and feedlot region have been linked to BRD incidence (Cernicchiaro et al, 2012b). Variation in BRD incidence with the year and season of feedlot entry have been described in several studies (Cernicchiaro et al, 2012a;Cernicchiaro et al, 2012b;Martin et al, 1988;Snowder et al, 2006b).…”

“…Source region and feedlot region have been linked to BRD incidence (Cernicchiaro et al, 2012b). Variation in BRD incidence with the year and season of feedlot entry have been described in several studies (Cernicchiaro et al, 2012a;Cernicchiaro et al, 2012b;Martin et al, 1988;Snowder et al, 2006b). Increased risk of BRD in the autumn and summer has been reported in large North American studies (Cernicchiaro et al, 2012b, c), but univariable associations between arrival quarter and cohort-level BRD incidence did not persist in multivariable models in another study (Sanderson et al, 2008).…”

“…Several animal characteristics have been associated with increased risk of BRD, including breed, with the Hereford breed consistently associated with increased risk (Cusack et al, 2007;Hägglund et al, 2007;Snowder et al, 2006a), sex, typically with higher risk in steers (Alexander et al, 1989;Cernicchiaro et al, 2012a;Cernicchiaro et al, 2012b;Sanderson et al, 2008;Snowder et al, 2006b), and bodyweight, with lighter animals being at higher risk (Cernicchiaro et al, 2012a;Reinhardt et al, 2009;Sanderson et al, 2008;Snowder et al, 2006b). The influence of age was assessed in a bull testing facility population; younger age at arrival was associated with fever (used as a proxy for BRD) after adjusting for weight (Townsend et al, 1989).…”