Prevalence, severity, and relationships of lung lesions, liver abnormalities, and rumen health scores measured at slaughter in beef cattle1

Abstract

An array of management tools exists within the beef industry to improve animal welfare and productivity; however, the ability to assess the outcomes of these tools is needed. Deficiencies in management commonly manifest as bovine respiratory disease complex or nutritional disorders such as acidosis; therefore, lung, liver, and rumen gross pathology lesions present at slaughter were measured as part of the Harvest Audit Program (HAP) and associations with performance determined. Individual gross pathology data from 19,229 cattle at commercial packing plants in Kansas and Texas were collected. Corresponding individual preharvest and carcass data were obtained on a subset of 13,226 cattle. Associations between lesions and performance were modeled using multivariable mixed effect models. Regression coefficients were used for estimation of lesion associative effects on continuous outcomes and odds ratios for dichotomous outcomes. Across the entire population, 67.3% of the cattle had no pulmonary lesions; 22.5 and 9.8% of cattle displayed mild and severe lesions, respectively. Severe pulmonary lesions were associated with a decreased ADG of 0.07 kg and a HCW 7.1 kg less than cohorts with no pulmonary lesions (P < 0.01). Overall, 68.6% of cattle observed had normal livers. Of cattle severely affected by liver abscesses (A+; 4.6%), 14.9% also displayed severe pulmonary lesions and 28.3% displayed mild pulmonary lesions. Rumenitis lesions were observed in 24.1% of the overall study population. Of cattle with mildly abscessed livers (A-), moderately abscessed livers (A), and severely abscessed livers, 20.6, 21.6, and 9.24% displayed mild or severe rumenitis lesions at slaughter. Severe rumenitis lesions were associated with a significant decrease in ADG and HCW (0.025 and 2.20 kg, respectively; P < 0.001). Although the majority of the cattle in this population would be considered low risk, after adjustments for cattle with multiple lesions, 22.9% of cattle in the overall population were observed with a severe lesion (lung, liver, or rumen). In conclusion, a gross pathology monitoring system is feasible and the 22.9% prevalence of severe lesions (lung, liver, or rumen) indicates that significant opportunity exists to improve beef cattle health, well-being, and productivity. Data generated using HAP may be used to support decisions concerning the implementation or removal of managerial practices and health interventions in beef cattle production systems.

Ruminal pH, short-chain fatty acid concentrations, and serum acute phase protein concentrations during finishing for steers with and without rumen and liver pathology

“…The lack of ruminal pathology in 2 of the steers with liver pathology suggests that liver abscesses may not exclusively be caused by ruminal lesions and is similar to that found previously (Rezac et al, 2014). The lack of ruminal pathology in 2 of the steers with liver pathology suggests that liver abscesses may not exclusively be caused by ruminal lesions and is similar to that found previously (Rezac et al, 2014).…”

“…Moreover, Rezac et al (2014) reported a positive association between liver abscesses and ruminal lesions when assessed after slaughter. While the causative factors for liver abscesses and association between ruminal and liver lesions have been assessed, few studies have characterized ruminal fermentation in relation to formation of rumenitis and liver abscesses.…”

The monster we don't see: subclinical BRD in beef cattle

“…Since the initial observations linking AV lung lesions at packing plants to cattle that had never been observed to exhibit signs of BRD, there has been a continual flow of work published that documented similar findings (Thompson et al , 2006; Schneider et al , 2009; Leach et al , 2013; Busby, 2014; Rezac et al , 2014). The impact of BRD on growth has been variable but the range published by these researchers has been a decrease in ADG between 0.10 lbs day −1 and over 1 lbs day −1 .…”

Abscesso hepático em bovinos: Revisão

“…No entanto, a prevalência na maioria dos confinamentos varia de 12 a 32% (Nagaraja & Lechtenberg, 2007). Entretanto, dados recentes sugerem que a média se encontra entre 10 e 20% (Rezac et al, 2014). Com relação a incidência de abscessos hepáticos em bovinos confinados no Brasil, alguns trabalhos relatam a incidência de 2,5% e outros de 3,1% (Almeida et al, 2005, Vechiato et al, 2011.…”

“…Mas, em um estudo realizado por Rezac et al (2014) sobre a relação entre saúde ruminal e os abscessos hepáticos, verificou-se que 32% dos bovinos com ruminite moderada ou grave apresentaram abscessos hepáticos, já aqueles com a parede ruminal saudável a incidência foi de 19%.…”