Bovine respiratory disease (BRD) is the most costly disease affecting the cattle industry. The pathogenesis of BRD is complex and includes contributions from microbial pathogens as well as host, environmental and animal management factors. In this study, we utilized viral metagenomic sequencing to explore the virome of nasal swab samples obtained from feedlot cattle with acute BRD and asymptomatic pen-mates at six and four feedlots in Mexico and the USA, respectively, in April-October 2015. Twenty-one viruses were detected, with bovine rhinitis A (52.7 %) and B (23.7 %) virus, and bovine coronavirus (24.7 %) being the most commonly identified. The emerging influenza D virus (IDV) tended to be significantly associated (P=0.134; odds ratio=2.94) with disease, whereas viruses commonly associated with BRD such as bovine viral diarrhea virus, bovine herpesvirus 1, bovine respiratory syncytial virus and bovine parainfluenza 3 virus were detected less frequently. The detection of IDV was further confirmed using a real-time PCR assay. Nasal swabs from symptomatic animals had significantly more IDV RNA than those collected from healthy animals (P=0.04). In addition to known viruses, new genotypes of bovine rhinitis B virus and enterovirus E were identified and a newly proposed species of bocaparvovirus, Ungulate bocaparvovirus 6, was characterized. Ungulate tetraparvovirus 1 was also detected for the first time in North America to our knowledge. These results illustrate the Selected complete or partial genome sequences were submitted to GenBank/EMBL/DDBJ and accession numbers were obtained: BRBV strain

The efficacy of gamithromycin did not differ from that of tulathromycin for all outcomes except morbidity rate; calves administered gamithromycin had a higher BRDC morbidity rate than did calves administered tulathromycin. On the basis of the bioequivalence limits established for this dataset, gamithromycin was considered equivalent to tulathromycin for the control of BRDC.

Calves administered gamithromycin had a higher BRDC retreatment rate than did calves administered tulathromycin; otherwise, the clinical efficacy did not differ between the 2 treatments for the treatment of BRDC in feedlot calves.

The purpose of this study was to compare the effectiveness of tildipirosin (TIP) to tulathromycin (TUL) administered at arrival to reduce morbidity in beef heifers (Charolais; n=785; age=11.1ñ1.9 months; average body weight=830.9 ± 78.48 lb (376.9 ± 35.6 kg)) at high risk of developing bovine respiratory disease (BRD). BRD morbidity was lower in the TIP group (TIP=6.8%; TUL=20.9%; P<0.01) over the feeding period. Animals in the TIP group had greater average daily gain compared to heifers in the TUL group (TIP=2.49 lb (1.13 kg); TUL=2.34 lb (1.06 kg); P<0.01). No differences were observed between groups for number and severity of lung lesions. In the present study, tildipirosin was more effective than tulathromycin in reducing BRD morbidity and improving growth performance in newly received beef heifers considered at high risk for BRD.

Flunixin is a nonsteroidal anti‐inflammatory drug (NSAID) that has anti‐inflammatory, anti‐pyretic, and analgesic effects. Recently, a novel transdermal formulation was developed (Finadyne® Transdermal, MSD Animal Health) and is now the first NSAID registered to be administered as a pour‐on product in cattle. According to the manufacturer's instructions, the pour‐on product should be applied only to dry skin and exposure to rain should be avoided for at least 6 hr after application. The objective of the study was to evaluate the effect of simulated exposure to light or heavy rain on flunixin absorption and bioavailability within the first 4 hr after administration. Therefore, an isocratic HPLC method was developed to quantify flunixin concentrations in bovine serum by UV detection. Light rain decreased flunixin absorption only when rain started immediately after flunixin administration, while light rain starting more than 30 min after administration of flunixin had no effect on absorption. Absorption and bioavailability of flunixin was impacted under simulated heavy rain conditions, when exposure to rain occurred within one hour after the application of the pour‐on formulation, but not later.