Galyean Appreciation Club Review: revisiting nutrition and health of newly received cattle-what have we learned in the last 15 years?

Our objective was to review the literature related to the health and management of newly received cattle published since a previous review by Duff and Galyean (2007). Bovine respiratory disease (BRD) continues to be a major challenge for the beef industry. Depending on disease severity, animals treated for BRD have decreased performance and lowered carcass value. Diagnosis of BRD is less effective than desired, and progress on developing real-time, chute-side methods to diagnose BRD has been limited. Systems that combine lung auscultation with temperature and body weight data show promise. Assessment of blood metabolites and behavior monitoring offer potential for early identification of morbid animals. Vaccination and metaphylaxis continue to be important tools for the prevention and control of BRD, but antimicrobial resistance is a concern with antibiotic use. Dietary energy concentration and roughage source and level continue to be important topics. Mineral supplementation has received considerable attention, particularly the use of organic vs. inorganic sources and injectable minerals or drenches given on arrival. The use of probiotics and prebiotics for newly received cattle has shown variable results, but further research is warranted. The health and nutrition of newly received cattle will continue to be an important research area in the years to come.

Bovine respiratory disease (BRD) is a significant economic and animal welfare challenge for the beef industry. Experiments related to the health and management of newly received cattle published in the last 15 yr were reviewed. Limited progress is being made in developing accurate, real-time methods for diagnosis of BRD, and overall, diagnosis is less effective than desired. Measurement of lung and heart sounds combined with rectal temperature have been studied as diagnostic tools, as well as measurement of blood metabolites and remote monitoring of behavior. Vaccination for viral and bacterial BRD agents and mass treatment of cattle with antibiotics continue to be important tools for prevention and control of BRD, but the development of antimicrobial resistance is a concern. Energy and roughage concentration as well as roughage source continue to be important dietary considerations, as does mineral supplementation, with mineral source and injectable minerals receiving significant research attention. Probiotics and prebiotics fed to newly received cattle have shown variable results in terms of effects on the incidence of BRD and animal performance. Additional research is needed to define optimal diagnostic, management, and nutritional practices for newly received cattle.

Pharmacokinetics of tulathromycin following administration to stocker cattle with remote delivery devices.

Remote delivery devices (RDD) are used by some to administer antimicrobials (AM) to cattle when treatment by manual injection is logistically difficult. However, it is not clear that the pharmacokinetics (PK) of AM administered by RDD is comparable to that for AM administered by injection; thus, it is not certain that cattle treated by RDD experience equivalent AM effect. Fifteen crossbred beef steers (body weight [BW] = 302.5 ± 21.7 kg) were used in a three-way crossover study to determine the PK of tulathromycin following administration with RDD in the BQA injection triangle. Cattle were treated by each of three methods at 2.5 mg of tulathromycin per kg of BW with a 60 d washout period between treatments: 1) subcutaneous injection of tulathromycin (SC), 2) treatment by RDD delivered by air pump projector (AIR, Pneudart, Model 178B) at 4.5 m distance, and 3) treatment by RDD delivered by CO2-powered projector at 7.5 m (CO2, Pneudart, Model 176B). Blood was collected prior to injection and at various points up to 552 h post-administration, pharmacokinetic data were analyzed as a mixed model using animal as a random effect and method of administration, order of administration, and their interaction as fixed effects. Plasma creatine kinase (CK) was measured before treatment and at 24 h after treatment to determine the degree of muscle injury resulting from each treatment. Three darts administered by AIR did not discharge (20%; 95% CI = 4% to 48%); and results from these steers were excluded from analysis. Maximum plasma concentration (718, 702.6, and 755.5 µg/mL for SC, AIR, and CO2, respectively) and area under the concentration-time curve (17,885, 17,423, and 18,796 µg • h/mL for SC, AIR and CO, respectively) were similar and not significantly different between methods of administration. There was an effect of time (P = 0.0002), period (P = 0.0001), and interaction between method of administration and study period (P = 0.0210) on plasma concentration of CK. However, method of treatment (P = 0.6091), interaction between method and time (P = 0.6972), interaction between period and time (P = 0.6153), and 3-way interaction between method, period and time (P = 0.6804) were not different. Results suggest that PK of tulathromycin following delivery by RDD can be similar to subcutaneous injection; however, failure of RDD to discharge after delivery by some types of projectors can cause an important proportion of cattle to fail to receive drug as expected.

Three-dimensional transesophageal echocardiography for perioperative right ventricular assessment.

BACKGROUND: In high-risk cardiac procedures, dynamic analysis of right ventricular (RV) performance is desirable, but the geometric complexity of the RV limits the applicability of current two-dimensional echocardiographic imaging techniques. This study aimed to evaluate the utility of three-dimensional transesophageal echocardiography (TEE) for the perioperative assessment of RV function and dimensions. METHODS: Patients undergoing cardiac surgical procedures with complete TEE examinations were identified and reviewed according to current guidelines to exclude patients with significant coexisting valvular regurgitation. Full-volume, three-dimensional datasets were analyzed by two independent investigators using stand-alone software, and left ventricular and RV dimensions were recorded. RESULTS: Datasets from 50 patients undergoing cardiac surgical procedures were evaluated for this study. The mean RV volume was 111.7 mL (range, 37.5 to 349.7 mL) at end diastole and 67.6 mL (range, 25.5 to 274.4 mL) at end systole. Intraobserver reliability was 0.93 and 0.90 for end diastolic and 0.77 and 0.87 for end systolic volumes. The interobserver reliability for RV volumes was 0.83 at end diastole and 0.86 at end systole. The mean stroke volume was 43.6 mL (range, 12 to 111.2 mL) for the RV and 49.1 mL (range, 19.9 to 102.8 mL) for the left ventricle; the correlation coefficient between the two was 0.85. CONCLUSIONS: Three-dimensional TEE volumetric measurements were reproducible across a wide range of RV dimensions. As postulated by the continuity principle, stroke volume measurements between both ventricles correlated well, supporting the validity of this approach. Therefore, our work provides preliminary evidence that three-dimensional TEE offers reproducible information about RV function and size in the dynamic and complex perioperative setting of cardiac surgical procedures.

Reduction of Escherichia coli O157 in finishing beef cattle by various doses of Lactobacillus acidophilus in direct-fed microbials.

Our objective was to evaluate the effects of three doses of Lactobacillus acidophilus strain NP51 and a combination treatment of strains NP51 and NP45 on prevalence of Escherichia coli O157 in cattle. Three hundred steers were assigned randomly to 60 pens (five steers per pen) and received one of five treatments: (i) control, no added direct-fed microbial; (ii) HNP51, high dose of NP51 at 10(9) CFU per steer daily; (iii) MNP51, NP51 at 10(8) CFU per steer daily; (iv) LNP51, low dose of NP51 at 10(7) CFU per steer daily; and (v) NP51+45, NP51 at 10(9) CFU per steer daily and NP45 at 106 CFU per steer daily. All direct-fed microbial treatments included Propionibacterium freudenreichii at 10(9) CFU per steer. Individual rectal fecal samples were collected on arrival and every 28 days throughout the feeding period. Fecal and hide samples were collected on the day of harvest. Samples were analyzed for presence of E. coli O157 using immunomagnetic separation methods. Cattle receiving HNP51, MNP51, and LNP51 had a lower prevalence (P < 0.01) of E. coli O157 throughout the feeding period compared with the controls, and the dose response for NP51 was a linear decrease in prevalence with increasing dose (P < 0.01). No decrease in prevalence for cattle receiving the combination NP51+45 was detected compared with controls (P = 0.15). E. coli O157 prevalences averaged across collection times were 23.9, 10.5, 9.9, 6.8, and 17.3% for cattle in the control, LNP51, MNP51, HNP51, and NP51 +45 groups, respectively. Least squares mean estimates of fecal prevalence at harvest of E. coli O157 were 31.7, 12.5, 17.4, 8.2, and 41.6% among cattle in the control, LNP51, MNP51, HNP51, and NP51+45 groups, respectively. Least squares mean estimates of the percentage of positive hide samples at harvest were 8.7, 5.9, 4.8, 3.4, and 8.6% among cattle in the control, LNP51, MNP51, HNP51, and NP51+45 groups, respectively. The greatest decrease in E. coli O157 carriage was achieved using NP51 at 10(9) CFU per steer.