An evaluation of the economic effects of bovine respiratory disease on animal performance, carcass traits, and economic outcomes in feedlot cattle defined using four BRD diagnosis methods.

Bovine respiratory disease (BRD) causes significant economic losses to the feedlot industry due to decreased production and increased costs associated with treatment. This study aimed to assess the impacts of BRD on performance, carcass traits, and economic outcomes defined using four BRD diagnosis methods: number of BRD treatments an animal received, pleural lesions at slaughter, lung lesions at slaughter, and clinical BRD status defined using both treatment records and lung and pleural lesions. Crossbred steers (n = 898), with an initial body weight of 432 kg (± SD 51), were followed from feedlot entry to slaughter. Veterinary treatment records were collected and lungs scored at slaughter for lesions indicative of BRD. There was an 18% morbidity rate and a 2.1% BRD mortality rate, with an average net loss of AUD$1,647.53 per BRD mortality. Animals treated ≥3 times for BRD had 39.6 kg lighter carcasses at slaughter and returned an average of AUD$384.97 less compared to animals never treated for BRD (P < 0.001). Animals with severe lung lesions at slaughter grew 0.3 kg/d less, had 14.3 kg lighter carcasses at slaughter, and returned AUD$91.50 less than animals with no lung lesions (P < 0.001). Animals with subclinical and clinical BRD had 16.0 kg and 24.1 kg lighter carcasses, respectively, and returned AUD$67.10 and AUD$213.90 less at slaughter, respectively, compared to healthy animals that were never treated with no lesions (P < 0.001). The severity of BRD based on the number of treatments an animal received and the severity of lung and pleural lesions reduced animal performance, carcass weight and quality, and economic returns. Subclinical BRD reduced animal performance and economic returns compared to healthy animals; however, subclinical animals still had greater performance than animals with clinical BRD. This information can be used to plan for strategic investments aimed at reducing the impacts of BRD in feedlot cattle such as improved detection methods for subclinical animals with lesions at slaughter and BRD treatment protocols.

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

Bovine respiratory disease (BRD) is the most expensive disease affecting United States cattle. Recently weaned calves are the focus of prevention and treatment research. Identifying affected cattle early in the course of BRD is difficult. Intervention during the early stages of BRD improves treatment outcomes; however, cattle as prey animals are excellent at hiding signs of disease, especially if the caregiver has not gained their trust. Depression, appetite loss, and changes in respiratory character are the principal signs used to identify BRD. Rectal temperatures from cattle pulled for treatment are a final measure of evaluation. Cattle suffering from subclinical BRD frequently escape identification and treatment. Observations of lungs at packing plants for anterior ventral (AV) lesions frequently document higher BRD incidence rates than observed pre-harvest, suggesting subclinical BRD is common. Data from numerous studies document lower average daily gains (ADG) from cattle with AV lung lesions at packing plants that were not treated for BRD compared with cattle with normal lungs. Scoring lung lesions at the packing plant can be a useful tool for gaining insight into BRD incidence. Data indicate that BRD lowers ADG by 0.2 lbs on average, and lowers the USDA Quality Grade by 50 marbling points.

Bovine coronavirus associated syndromes.

Bovine coronaviruses, like other animal coronaviruses, have a predilection for intestinal and respiratory tracts. The viruses responsible for enteric and respiratory symptoms are closely related antigenically and genetically. Only 4 bovine coronavirus isolates have been completely sequenced and thus, the information about the genetics of the virus is still limited. This article reviews the clinical syndromes associated with bovine coronavirus, including pneumonia in calves and adult cattle, calf diarrhea, and winter dysentery; diagnostic methods; prevention using vaccination; and treatment, with adjunctive immunotherapy.

An evaluation of bovine respiratory disease complex in feedlot cattle: Impact on performance and carcass traits using treatment records and lung lesion scores.

The objective of this study was to investigate the effects of bovine respiratory disease (BRD) complex on economically important production traits with the use of health records in combination with lung lesion scores obtained at slaughter. Records from 5,976 animals were used in this study from cattle that were managed in Midwestern feedlots. Average daily gain for 3 different feeding periods (acclimation, on-test, and overall test) along with final BW were evaluated as performance measures. Hot carcass weight, LM area, subcutaneous fat cover, and marbling score were collected at slaughter. All calves were monitored by experienced feedlot personnel and treated according to the specific health protocol of each feedlot. Incidence of BRD was observed at a rate of 8.17%, and lung lesions at slaughter were present in 61.9% of cattle from a subpopulation (n = 1,665). From this group of cattle, the overall incidence of BRD, which was defined as cattle that had lung lesions, that were treated for BRD in the feedlot, or both, was 64.4%. Incidence of BRD in the feedlot decreased ADG during both the acclimation period (0.37 +/- 0.03 kg) and the overall test period (0.07 +/- 0.01 kg). Incidence of BRD also had significant effects on HCW and marbling score with reduction of 8.16 +/- 1.38 kg and 0.13 +/- 0.04, respectively, in treated cattle. The adverse effects on production traits tended to increase as the number of treatments increased. Potential decrease in performance and carcass merit observed in this study were associated with a decline of $23.23, $30.15, and $54.01 in carcass value when comparing cattle never treated with cattle treated once, twice, or 3 or more times, respectively. The presence of lung lesions did not have a significant effect on any of the traits; however, there was an association between the presence of active bronchial lymph nodes and less productivity of feedlot cattle.

Bovine respiratory disease: pathogenesis, clinical signs, and treatment in lightweight calves.

No matter what disease is being addressed, there are basic steps required for successful therapy. Failure to address each step systematically leaves a gap in the program that eventually shows up as inconsistency or failure in therapeutic efficacy. The focus in this article is on applying these steps in infectious bovine respiratory disease challenges in lightweight stocker calves.