An updated profile of the bovine acute phase response following an intravenous lipopolysaccharide challenge.

The objective was to provide an updated profile of the bovine acute-phase response to include recent advancements in technologies and expanded hematological, cytokine, and serum chemistry variables. Beef steers (n = 32; body weight [BW] = 251 ±â€…19.5 kg) were fitted with indwelling jugular catheters 1 d before lipopolysaccharide (LPS; 0.25 µg LPS/kg BW from Escherichia coli O111:B4) administration to facilitate serial blood collection. Rectal temperature was measured using indwelling probes, and ocular temperature was measured using infrared thermal imaging. Blood samples were collected for subsequent analysis of serum chemistry, hematology, and cytokine concentrations. Pearson correlation of rectal temperature and ocular infrared temperature was 0.61 (P < 0.01) and the Spearman correlation coefficient was 0.56 (P < 0.01). Interactions of hour × method were observed for ocular and rectal measurements of body temperature in response to endotoxin exposure. Maximum observed temperature was 39.6 °C at 2.5 h for both rectal and ocular measurements. Body temperature differed by method at hours 0.5, 2.5, 4.5, 7.5, 12.5, 36.5, and 47.5 (P < 0.01), but were not different otherwise. All variables of serum chemistry and complete blood count were influenced by LPS administration, except creatinine, serum glucose, and percent basophils (P ≤ 0.02). Alanine aminotransferase and alkaline phosphatase peaked at hour 2 relative to LPS administration, returned to baseline at hour 12 and continued to decrease below the baseline value at hour 48 (P < 0.01). Total protein concentration decreased 3% in response to LPS (P = 0.01). Total white blood cell count decreased 75% after LPS administration at hour 1 (P < 0.01). Lymphocyte count recovered to baseline at hour 6; sooner than neutrophil count at hour 36. Serum cortisol concentration increased 294% relative to baseline at hour 1 followed by a sustained decrease and return to normal concentration at hour 4 (P < 0.01). Additionally, circulating cytokine concentrations changed with time in response to the LPS challenge, excluding aFGF, bFGF, IGF-1, IL-2, IL-4, MCP-1, and ANG-1 (P ≤ 0.08). Maximum observed concentration of TNF-α at hour 1 was 117% greater than the pre-challenge value (P < 0.01). Data presented herein add to existing works to understand the endocrine and immune responses of beef steers administered exogenous LPS, and incorporate recent technologies, additional biomarkers, and an expanded cytokine profile that can be used as referential data in future research.

The acute phase response is a component of innate immunity initiated by infection, inflammation, or tissue damage. Characteristics of these host responses can be emulated by administration of exogenous endotoxin and closely studied in controlled settings to understand the response to inflammatory diseases that are commonplace in livestock production. Beef steers were administered exogenous lipopolysaccharide, and responses of body temperature, serum chemistry, complete blood count, cortisol, and cytokines were quantified. A moderate correlation of body temperature measured via rectal probe or ocular infrared temperature was observed, but both methods had a similar temporal response and were sensitive to changes in body temperature. Response of serum chemistry variables highlighted the links between metabolism and the inflammatory response. The initial inflammatory response was initiated by cortisol and pro-inflammatory cytokines at hour 1 and tempered by anti-inflammatory cytokines at hours 3 and 4. Therefore, these data offer an expanded view to our understanding of the bovine acute phase response.

Evaluation of First Treatment Timing, Fatal Disease Onset, and Days from First Treatment to Death Associated with Bovine Respiratory Disease in Feedlot Cattle.

Bovine respiratory disease (BRD) is a frequent beef cattle syndrome. Improved understanding of the timing of BRD events, including subsequent deleterious outcomes, promotes efficient resource allocation. This study's objective was to determine differences in timing distributions of initial BRD treatments (Tx1), days to death after initial treatment (DTD), and days after arrival to fatal disease onset (FDO). Individual animal records for the first BRD treatment (n = 301,721) or BRD mortality (n = 19,332) were received from 25 feed yards. A subset of data (318-363 kg; steers/heifers) was created and Wasserstein distances were used to compare temporal distributions of Tx1, FDO, and DTD across genders (steers/heifers) and the quarter of arrival. Disease frequency varied by quarter with the greatest Wasserstein distances observed between Q2 and Q3 and between Q2 and Q4. Cattle arriving in Q3 and Q4 had earlier Tx1 events than in Q2. Evaluating FDO and DTD revealed the greatest Wasserstein distance between cattle arriving in Q2 and Q4, with cattle arriving in Q2 having later events. Distributions of FDO varied by gender and quarter and typically had wide distributions with the largest 25-75% quartiles ranging from 20 to 80 days (heifers arriving in Q2). The DTD had right-skewed distributions with 25% of cases occurring by days 3-4 post-treatment. Results illustrate temporal disease and outcome patterns are largely right-skewed and may not be well represented by simple arithmetic means. Knowledge of typical temporal patterns allows cattle health managers to focus disease control efforts on the correct groups of cattle at the appropriate time.

Nasopharyngeal Bacterial Prevalence and Microbial Diversity at First Treatment for Bovine Respiratory Disease (BRD) and Its Associations with Health and Mortality Outcomes in Feedyard Cattle.

Bovine respiratory disease (BRD) is an economically important disease in feedyards influencing both animal welfare and antimicrobial utilization. Major pathogens associated with BRD have been identified in previous research, but little information is available on the relationship between nasopharyngeal microbiota and health outcomes. The objective of this study was to identify potential associations between nasopharyngeal microbiota and antimicrobial resistance patterns of clinical cases that lived or died compared to non-diseased controls. Enrolled animals were subdivided based on clinical disease status and case outcome (subsequent mortality). Deep nasopharyngeal swabs were collected on enrolled animals and submitted for bacterial isolation, antimicrobial susceptibility determination, and metagenomics analysis. Enrolled cattle were represented in three groups: animals at first treatment for BRD that subsequently died (BRDM, n = 9), animals at first treatment for BRD that subsequently lived (BRDL, n = 15), and animals that were never treated for BRD during the feeding phase (CONT, n = 11). Antimicrobial resistance patterns for Pasteurella multocida illustrated cattle in each outcome category had isolates that were pan-susceptible or only showed resistance to oxytetracycline. The relative abundance of species and genera illustrated few differences among the three outcomes. Higher alpha diversity was identified in BRDL compared to CONT at the species level, and both BRDL and BRDM showed increased alpha diversity compared to CONT at the general level. Overall, this work illustrated nasopharyngeal microbiota showed relatively few differences among BRD cases that lived or died compared to animals without BRD.

Antimicrobial and Biological Methods to Control Liver Abscesses.

Antimicrobial products are approved for the control of liver abscesses with varying amounts of data. When compared to negative controls, tylosin has the most data to support a reduction in total (risk ratio 0.34) and severe A+ (risk ratio 0.31) liver abscesses. Due to the reduction in the use of antimicrobials, vaccination to control liver abscess prevalence is intriguing. However, available vaccines do not appear to be effective in controlling the prevalence of liver abscesses, especially when the disease prevalence is high.

Behavioral and performance response associated with administration of intravenous flunixin meglumine or oral meloxicam immediately prior to surgical castration in bull calves.

The objective of this study was to determine the effects of flunixin meglumine or meloxicam on behavioral response and performance characteristics associated with surgical castration in crossbred bulls. Intact male Bos taurus calves (n = 252; averaging 176 kg) were randomly allocated into one of three treatment groups within pen: control (CON), flunixin meglumine (FLU; 2.2 mg/kg intravenous injection), or meloxicam (MEL; 2.0 mg/kg per os). The individual animal was the experimental unit. Calves were individually weighed on days 0 and 14 of the trial to evaluate performance outcomes. On study day 0, treatments were administered, according to their random allocation, immediately prior to surgical castration using the Henderson tool method. Visual analog scale (VAS) assessment and categorical attitude score (CAS) were collected on days -1, 0 (6 h post-castration), 1, 2, 3, and 4 in the study. The VAS was assigned using a 100 mm horizontal line with "normal" labeled at one end of the line and "moribund" at the other end of the horizontal line. The masked observer assigned a mark on the horizontal line based upon the observed severity of pain exhibited by that individual animal. The CAS was assigned by the same observer using five different categories with a score of 0 being "normal". Average daily gain tended (P = 0.09) to be associated with the treatment group, and MEL had a greater (P = 0.04) average daily gain through day 14 compared with CON. A significant (P < 0.01) treatment by day interaction was indicated for VAS score, and MEL had lower VAS scores on days 0, 1, 2, and 3 post-castration compared with CON; FLU had lower VAS scores on days 0 and 1 compared with CON. A significant treatment by day interaction was not present (P = 0.25) for CAS. The FLU had lesser percent CAS ≥1 (17.5%; P = 0.05) compared with CON (29.4%); MEL has lesser percent CAS ≥1 observations (14.9%; P = 0.01) compared with CON. The median VAS increased as CAS was more severe. Results indicated MEL and FLU calves temporally improved behavioral responses following surgical castration with positive numerical trends for a 14 d average daily gain (ADG). The VAS system appeared to be an effective method of subjective evaluation of pain in beef calves in this study. Route of administration, duration of therapy, and low relative cost make oral meloxicam a reasonable analgesic treatment in calves when administered at the time of surgical castration.

Evaluation of the reticulorumen pH throughout the feeding period for beef feedlot steers maintained in a commercial feedlot and its association with liver abscesses.

OBJECTIVE: To evaluate the reticulorumen pH of beef feedlot steers throughout the feeding period and to assess the association between the respective durations that the reticulorumen pH was ≤ 5.6 (subacute ruminal acidosis) and ≤ 5.2 (acute ruminal acidosis) and liver abscess severity. ANIMALS: 59 feedlot steers (mean body weight, 349.5 kg). PROCEDURES: On day 0, each steer was orally administered an electronic bolus that monitored the reticulorumen pH every 10 minutes for 150 days. Steers were transitioned from a starter to intermediate ration on day 8 (transition 1) and from the intermediate to finish ration on day 19 (transition 2). The ration carbohydrate and megacalorie contents increased with each transition. During each transition, the lower megacalorie ration was fed at the 8:00 am feeding and the higher megacalorie ration was fed at the 2:00 pm feeding for 3 days before the higher megacalorie ration was fed extensively. Steers were sent to slaughter after 182 days; each carcass was assessed for liver abscesses. RESULTS: The diurnal reticulorumen pH pattern was characterized by a peak at 7:00 am and nadir at 8:00 pm. The mean percentages of time that the reticulorumen pH was ≤ 5.6 and ≤ 5.2 were more than 10-fold greater during transition 1, compared with during transition 2, and were significantly greater for steers with extensive liver abscesses than for steers without extensive liver abscesses. CONCLUSIONS AND CLINICAL RELEVANCE: Efforts to minimize the duration that the reticulorumen pH is ≤ 5.6 might mitigate liver abscess formation in feedlot cattle.

Determining potential pregnancy status differences based on a new method of yearling heifer prebreeding examination.

The study objective was to evaluate the Ready-Intermediate-Problem (RIP) replacement heifer evaluation matrix's ability to classify heifers into groups with differing reproductive outcomes. Beef heifers (n = 341) from six Kansas herds were classified according to RIP matrix guidelines and then exposed to AI breeding, bull breeding, or a combination of both as per the management plans for each participating herd. Following the breeding season the heifers were evaluated to determine pregnancy status, AI pregnancy status, days bred, and the number of 21 day cycles needed during the breeding season to become pregnant. After the breeding season, 298 (87%) of the heifers were pregnant, 204 (68%) of which became pregnant in the first 21 days of the breeding season. There was a significant interaction (P = 0.01) in RIP classification and pregnancy by 21 day cycle. Ready classified heifers had a significantly greater risk of becoming pregnant after a single AI exposure (P = 0.03) and in the first 21-day cycle (P = 0.02) compared to Problem classified heifers, and significantly less risk of being non-pregnant at the end of the breeding season (P < 0.01) compared to Problem classified heifers. The RIP matrix can be useful for classifying heifers prior to the onset of the breeding season. Further research is needed to evaluate the matrix in other settings and populations of U.S. beef heifers as well as at different intervals between evaluation and the start of breeding season.

Factors associated with yearling bulls passing subsequent breeding soundness evaluations after failing an initial evaluation.

OBJECTIVE To determine the proportion of yearling beef bulls classified as satisfactory potential breeders when reevaluated after failing an initial breeding soundness evaluation (BSE) and identify any factors at initial BSE that predicted satisfactory performance at reevaluation. DESIGN Retrospective observational study. ANIMALS 2,064 beef bulls between 11 and 14 months of age at first BSE, evaluated from 2006 to 2014. PROCEDURES For each bull, data on age (categorized by month), breed, and BSE findings were extracted from the medical records. Bulls were classified as satisfactory potential breeders if they met Society for Theriogenology standards at the initial BSE or up to 2 subsequent reevaluations. Generalized linear mixed models were generated to assess potential associations between certain variables at initial BSE and passing that evaluation or passing subsequent BSEs after initial failure. RESULTS 1,921 of 2,064 (93.1%) yearling bulls passed 1 of up to 3 BSEs. The proportion of yearling bulls that were not classified as satisfactory during initial BSE but were later classified as satisfactory was 143 of 287 (49.8%). A significant interaction was identified between bull age and breed in the probability of passing the initial evaluation. No variable, including breed, age, scrotal circumference per day of age, and spermatozoa morphology at initial BSE, significantly predicted passing subsequent reevaluations after failing an initial BSE. CONCLUSIONS AND CLINICAL RELEVANCE Age and breed information should be considered when deciding the age at which initial BSE should be scheduled for a yearling bull cohort.

Evaluation of infrared thermography as a diagnostic tool to predict heat stress events in feedlot cattle.

OBJECTIVE To determine whether infrared thermographic images obtained the morning after overnight heat abatement could be used as the basis for diagnostic algorithms to predict subsequent heat stress events in feedlot cattle exposed to high ambient temperatures. ANIMALS 60 crossbred beef heifers (mean ± SD body weight, 385.8 ± 20.3 kg). PROCEDURES Calves were housed in groups of 20 in 3 pens without any shade. During the 6 am and 3 pm hours on each of 10 days during a 14-day period when the daily ambient temperature was forecasted to be > 29.4°C, an investigator walked outside each pen and obtained profile digital thermal images of and assigned panting scores to calves near the periphery of the pen. Relationships between infrared thermographic data and panting scores were evaluated with artificial learning models. RESULTS Afternoon panting score was positively associated with morning but not afternoon thermographic data (body surface temperature). Evaluation of multiple artificial learning models indicated that morning body surface temperature was not an accurate predictor of an afternoon heat stress event, and thermographic data were of little predictive benefit, compared with morning and forecasted weather conditions. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated infrared thermography was an objective method to monitor beef calves for heat stress in research settings. However, thermographic data obtained in the morning did not accurately predict which calves would develop heat stress later in the day. The use of infrared thermography as a diagnostic tool for monitoring heat stress in feedlot cattle requires further investigation.

Calving distributions of individual bulls in multiple-sire pastures.

The objective of this project was to quantify patterns in the calving rate of sires in multiple-sire pastures over seven years at a large-scale cow-calf operation. Data consisted of reproductive and genomic records from multiple-sire breeding pastures (n = 33) at the United States Meat Animal Research Center (USMARC) from 2007 to 2013. Calving intervals were analyzed in 21-day periods. A ranking system for each bull was developed based on the calving rate per pasture over the breeding season, with Rank 1 = the bull with greatest calving rate, Rank 3 = the bull with the least calving rate, and Rank 2 = all other bulls. A total of 179 bulls and 3703 calves were successfully genotyped over seven years. A uniform distribution described the expected percentage of calves sired per rank within pasture. Rank 1 bulls sired 113% greater calves than the expected pasture-average, Rank 2 bulls sired 6% less than expected, and Rank 3 bulls sired 81% less than expected. A rank by calving interval interaction effect was identified (P < 0.05). A Rank 1 bull in calving interval 1 produced a greater average percent of the total calf crop over the entire season, compared to a Rank 2 and Rank 3 bull. The calving rate for individual sires is not homogeneous and there is a large difference between bulls siring the greatest and least number of calves. More research is needed to determine how rank changes over multiple breeding years and its association with dominance, libido, and fertility.

Use of three-dimensional accelerometers to evaluate behavioral changes in cattle experimentally infected with bovine viral diarrhea virus.

OBJECTIVE To assess the use of 3-D accelerometers to evaluate behavioral changes in cattle experimentally infected with a low-virulent strain of bovine viral diarrhea virus (BVDV). ANIMALS 20 beef steers (mean weight, 238 kg). PROCEDURES Calves were allocated to a BVDV (n = 10) or control (10) group. On day 0, calves in the BVDV group were inoculated with a low-virulent strain of BVDV (4 × 10(6) TCID50, intranasally), and calves in the control group were sham inoculated with BVDV-free medium (4 mL; intranasally). An accelerometer was affixed to the right hind limb of each calf on day -7 to record activity (lying, walking, and standing) continuously until 35 days after inoculation. Baseline was defined as days -7 to -1. Blood samples were collected at predetermined times for CBC, serum biochemical analysis, virus isolation, and determination of anti-BVDV antibody titers. RESULTS All calves in the BVDV group developed viremia and anti-BVDV antibodies but developed only subclinical or mild disease. Calves in the control group did not develop viremia or anti-BVDV antibodies. Mean time allocated to each activity did not differ significantly between the BVDV and control groups on any day except day 8, when calves in the BVDV group spent less time standing than the calves in the control group. Following inoculation, calves in both groups tended to spend more time lying and less time walking and standing than they did during baseline. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that behavioral data obtained by accelerometers could not distinguish calves subclinically infected with BVDV from healthy control calves. However, subtle changes in the behavior of the BVDV-infected calves were detected and warrant further investigation.

Using Feedlot Operational Data to Make Valid Conclusions for Improving Health Management.

Feedlot operational data can be useful for monitoring cattle health and performance outcomes and evaluating associations between these outcomes and potentially important cattle population or management factors. Operational data are inherently relevant to clients; however, there are potential limitations that need to be considered to make appropriate conclusions. Assessing data quality, potential for bias, data distributions, and multiple health outcomes can provide a more thorough understanding of feedlot cattle health and factors that may affect health management systems. Accurate and useful information is derived only when the advantages and limitations of the data and the analysis process are fully understood.

Optimizing Feedlot Diagnostic Testing Strategies Using Test Characteristics, Disease Prevalence, and Relative Costs of Misdiagnosis.

Diagnostic tests are commonly used by feedlot practitioners and range from clinical observations to more advanced physiologic testing. Diagnostic sensitivity and specificity, estimated prevalence in the population, and the costs of misdiagnoses need to be considered when selecting a diagnostic test strategy and interpreting results. This article describes methods for evaluating diagnostic strategies using economic outcomes to evaluate the most appropriate strategy for the expected situation. The diagnostic sensitivity and specificity, and expected prevalence influence the likelihood of misdiagnosis in a given population, and the estimated direct economic impact can be used to quantify differences among diagnostic strategies.

Systematic review and meta-analysis of the effectiveness of commercially available vaccines against bovine herpesvirus, bovine viral diarrhea virus, bovine respiratory syncytial virus, and parainfluenza type 3 virus for mitigation of bovine respiratory disease complex in cattle.

OBJECTIVE: To evaluate and analyze data from controlled studies on the effectiveness of vaccinating cattle with commercially available viral antigen vaccines for mitigation of the effects of bovine respiratory disease complex (BRDC). DESIGN: Systematic review and meta-analysis. SAMPLE: 31 studies comprising 88 trials. PROCEDURES: Studies that reported the effectiveness of commercially available bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), and parainfluenza type 3 virus (PI3) vaccines for protection of cattle against BRDC or its components were included in the analysis. Studies or trials were categorized as natural exposure or experimental challenge and were further divided by the viral antigen evaluated and vaccine type (modified-live virus [MLV] or inactivated vaccine). Meta-analysis was performed; summary Mantel-Haenszel risk ratios were determined, and Forest plots were generated. RESULTS: In natural exposure trials, beef calves vaccinated with various antigen combinations had a significantly lower BRDC morbidity risk than did nonvaccinated control calves. In trials evaluating BHV-1 and MLV BVDV vaccines in experimental challenge models, vaccinated calves had a lower BRDC morbidity risk than did control calves; however, in experimental challenge trials evaluating MLV BRSV and PI3 vaccines, no significant difference in morbidity or mortality risk was found between vaccinated and control calves. CONCLUSIONS AND CLINICAL RELEVANCE: Estimating clinical efficacy from results of experimental challenge studies requires caution because these models differ substantially from those involving natural exposure. The literature provides data but does not provide sufficiently strong evidence to guide definitive recommendations for determining which virus components are necessary to include in a vaccination program for prevention or mitigation of BRDC in cattle.

Relationship between rectal temperature at first treatment for bovine respiratory disease complex in feedlot calves and the probability of not finishing the production cycle.

OBJECTIVE-To determine the relationship between rectal temperature at first treatment for bovine respiratory disease complex (BRDC) in feedlot calves and the probability of not finishing the production cycle. DESIGN-Retrospective data analysis. ANIMALS-344,982 calves identified as having BRDC from 19 US feedlots from 2000 to 2009. PROCEDURES-For each calf, data for rectal temperature at initial treatment for BRDC and various performance and outcome variables were analyzed. A binary variable was created to identify calves that did not finish (DNF) the production cycle (died or culled prior to cohort slaughter). A mixed general linear model and receiver operating characteristic curve were created to evaluate associations of rectal temperature, number of days in the feedlot at time of BRDC diagnosis, body weight, quarter of year at feedlot arrival, sex, and all 2-way interactions with rectal temperature with the probability that calves DNF. RESULTS-27,495 of 344,982 (7.97%) calves DNF. Mean rectal temperature at first treatment for BRDC was 40.0°C (104°F). As rectal temperature increased, the probability that a calf DNF increased; however, that relationship was not linear and was influenced by quarter of year at feedlot arrival, sex, and number of days in the feedlot at time of BRDC diagnosis. Area under the receiver operating characteristic curve for correct identification of a calf that DNF was 0.646. CONCLUSIONS AND CLINICAL RELEVANCE-Rectal temperature of feedlot calves at first treatment for BRDC had limited value as a prognostic indicator of whether those calves would finish the production cycle.

Effects of weather variables on thermoregulation of calves during periods of extreme heat.

OBJECTIVE: To determine effects of ambient temperature, relative humidity, wind speed, relative barometric pressure, and temperature-humidity index (THI) on nasal submucosal and rectal temperatures in cattle during extreme summer conditions. ANIMALS: 20 black crossbred beef heifers (mean body weight, 217.8 kg). PROCEDURES: Nasal submucosal and rectal temperatures were monitored every 2 hours for 24 hours on 3 nonconsecutive days when ambient temperature was forecasted to exceed 32.2°C. Ambient temperature, relative humidity, wind speed, and relative barometric pressure were continuously monitored at a remote weather station located at the research facility. The THI was calculated and used in the livestock weather safety index (LWSI). Relationships between nasal submucosal or rectal temperature and weather variables were evaluated. RESULTS: Nasal submucosal and rectal temperatures were related to all weather variables monitored. A positive relationship was determined for ambient temperature and THI with both nasal submucosal and rectal temperatures. A negative relationship was evident for nasal submucosal and rectal temperature with relative humidity, wind speed, and relative barometric pressure. Nasal submucosal and rectal temperatures increased with increasing severity of LWSI category. CONCLUSIONS AND CLINICAL RELEVANCE: Effects of environmental conditions on thermoregulation in calves exposed to extreme heat were detected. The positive relationship between nasal submucosal temperature and ambient temperature and THI raised concerns about the efficacy of intranasal administration of temperature-sensitive modified-live virus vaccines during periods of extreme heat. Environmental conditions must be considered when rectal temperature is used as a diagnostic tool for identifying morbid cattle.

Effect of transportation during periods of high ambient temperature on physiologic and behavioral indices of beef heifers.

OBJECTIVE: To determine the effect of transportation during periods of high ambient temperature on physiologic and behavioral indices of beef heifers. ANIMALS: 20 heifers (mean body weight, 217.8 kg). PROCEDURES: Ten heifers were transported 518 km when the maximum ambient temperature was ≥ 32.2°C while the other 10 heifers served as untransported controls. Blood samples were collected from transported heifers at predetermined intervals during the transportation period. For all heifers, body weights, nasal and rectal temperatures, and behavioral indices were measured at predetermined intervals for 3 days after transportation. A week later, the entire process was repeated such that each group was transported twice and served as the control twice. RESULTS: Transported heifers spent more time near the hay feeder on the day of transportation, had lower nasal and rectal temperatures for 24 hours after transportation, and spent more time lying down for 2 days after transportation, compared with those indices for control heifers. Eight hours after transportation, the weight of transported heifers decreased 6%, whereas that of control heifers increased 0.6%. At 48 hours after initiation of transportation, weight, rectal temperature, and time spent at various pen locations did not differ between transported and control heifers. Cortisol concentrations were higher 4 hours after initiation of transportation, compared with those determined just prior to transportation. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated transportation during periods of high ambient temperatures caused transient changes in physiologic and behavioral indices of beef heifers.

Remote noninvasive assessment of pain and health status in cattle.

Cattle behavior is frequently monitored to determine the health of the animal. This article describes potential benefits and challenges of remotely monitoring cattle behavior with available methodologies. The behavior of interest, labor required, and monitoring expenses must be considered before deciding which remote behavioral monitoring device is appropriate. Monitoring the feeding behavior of an animal over time allows establishment of a baseline against which deviations can be evaluated. Interpretation of multiple behavioral responses as an aggregate indicator of animal wellness status instead of as individual outcomes may be a more accurate measure of true state of pain or wellness.

Assessment of behavioral changes associated with oral meloxicam administration at time of dehorning in calves using a remote triangulation device and accelerometers.

BACKGROUND: Dehorning is common in the cattle industry, and there is a need for research evaluating pain mitigation techniques. The objective of this study was to determine the effects of oral meloxicam, a non-steroidal anti-inflammatory, on cattle behavior post-dehorning by monitoring the percent of time spent standing, walking, and lying in specific locations within the pen using accelerometers and a remote triangulation device. Twelve calves approximately ten weeks of age were randomized into 2 treatment groups (meloxicam or control) in a complete block design by body weight. Six calves were orally administered 0.5 mg/kg meloxicam at the time of dehorning and six calves served as negative controls. All calves were dehorned using thermocautery and behavior of each calf was continuously monitored for 7 days after dehorning using accelerometers and a remote triangulation device. Accelerometers monitored lying behavior and the remote triangulation device was used to monitor each calf's movement within the pen. RESULTS: Analysis of behavioral data revealed significant interactions between treatment (meloxicam vs. control) and the number of days post dehorning. Calves that received meloxicam spent more time at the grain bunk on trial days 2 and 6 post-dehorning; spent more time lying down on days 1, 2, 3, and 4; and less time at the hay feeder on days 0 and 1 compared to the control group. Meloxicam calves tended to walk more at the beginning and end of the trial compared to the control group. By day 5, the meloxicam and control group exhibited similar behaviors. CONCLUSIONS: The noted behavioral changes provide evidence of differences associated with meloxicam administration. More studies need to be performed to evaluate the relationship of behavior monitoring and post-operative pain. To our knowledge this is the first published report demonstrating behavioral changes following dehorning using a remote triangulation device in conjunction with accelerometers.

Clinical, behavioral, and pulmonary changes in calves following inoculation with Mycoplasma bovis.

OBJECTIVE: To characterize clinical and behavioral changes in calves following inoculation with Mycoplasma bovis and evaluate relationships between those changes and pulmonary disease. ANIMALS: 22 healthy Holstein steers. PROCEDURES: 20 calves were inoculated intranasally with < 10(8) CFU or > 10(9) CFU of M bovis. Calves were assigned a clinical illness score (CIS) on a scale of 1 through 4 twice daily on the basis of severity of cough, labored breathing, and lethargy. For each calf, distance traveled and time spent near the waterer, feed bunk, or shelter were determined via a remote location monitoring device. Calves were euthanized and necropsied 22 days after inoculation. RESULTS: 13 calves became clinically ill after challenge inoculation; 3 calves were euthanized within 20 days. Among all calves, consolidation was evident in 0% to 79.9% of the lungs; extent of lung consolidation did not differ between the challenge dose groups. Distance traveled and percentages of time spent in proximity to the feed bunk and shelter were associated with CIS; calves with more severe disease traveled less distance and spent less time at the feed bunk and more time in the shelter. Distance traveled by calves was negatively associated with extent of lung consolidation (< or ≥ 10% of lungs affected); this effect was modified by trial day. CONCLUSIONS AND CLINICAL RELEVANCE: Following inoculation with M bovis, calf behavior patterns were associated with both CIS and severity of pulmonary disease. Use of behavior monitoring systems may aid in recognition of respiratory tract disease in calves.