Characterizing the diagnostic sensitivity and specificity of pain biomarkers in cattle using receiver operating characteristic curves.

Biomarkers are used to assess pain and analgesic drug efficacy in livestock. However, often the diagnostic sensitivity and specificity of these biomarkers for different painful conditions over time have not been described. Receiver operating characteristic (ROC) curves are graphical plots that illustrate the diagnostic ability of a test as its discrimination threshold is varied. The objective of this analysis was to use area under the curve (AUC) values derived from ROC analysis to characterize the predictive value of potential pain biomarkers at specific time points following a painful stimulus. The biomarkers included in the analysis were plasma cortisol, salivary cortisol, hair cortisol, infrared thermography (IRT), mechanical nociceptive threshold (MNT), substance P, kinematic gait analysis, and a visual analog scale for pain. A total of 7,992 biomarker outcomes collected from 7 pain studies involving pain associated with castration, dehorning, lameness, and abdominal surgery were included in the analysis. Each study consisted of 3 treatments: uncontrolled pain (tissue damage), no pain (handled controls), and analgesic use (tissue damage, administered a nonsteroidal anti-inflammatory drug). Results comparing analgesic effects to uncontrolled pain consistently yielded AUC values >0.7 (95% confidence interval: 0.40 to 0.99) for plasma cortisol (time points: 1.5, 2, 3, 4, 6, and 8 h), hair cortisol (time point: 62 d), and IRT (time point: 72 h). Results comparing analgesic effects to uncontrolled pain consistently yielded AUC values <0.7 (95% confidence interval: 0.28 to 0.90) for salivary cortisol (6, 13, 20, 34, 48, and 62 d); MNT (6, 25, and 49 h); substance P (1, 2, 3, 4, 6, 8, 12, 18, 24, 48, 72, 96, 120, 144, 312, 480, 816, 1,152, and 1,488 h); kinematic gait analysis including area (8, 16, 48, 72, 96, and 120 h), force (8, 16, 24, 48, 72, 96, and 120 h), and pressure (8, 16, 24, 48, 72, 96, and 120 h); and a visual analog scale for pain (1, 2, 3, 4, 5, and 6 d). These results indicate that ROC analysis can be used to characterize the predictive value of pain biomarkers and provide new knowledge on the diagnostic accuracy of pain biomarkers within this data set. This analysis, using data from 7 studies, was a preliminary approach to identify biomarkers and collection time points that could inform additional analytical approaches or meta-analyses with larger sample sizes, which are needed to further validate these hypotheses and conclusions.

The effect of the forage-to-concentrate ratio of the partial mixed ration and the quantity of concentrate in an automatic milking system for lactating Holstein cows.

This study was conducted to evaluate the effects of the forage-to-concentrate ratio of the partial mixed ration (PMR) and the quantity of concentrate offered in an automated milking system (AMS), in a feed-first guided-flow barn, on the behavior and performance of dairy cows. Eight ruminally cannulated multiparous Holstein cows were used in a replicated 4 × 4 Latin square balanced for carry-over effects. Treatments were arranged in a 2 × 2 factorial consisting of a PMR that contained (dry matter basis) either a low (54:46; L-FOR) or a high (64:36; H-FOR) forage-to-concentrate ratio and AMS concentrate provision to achieve low (2 kg/d; L-AMS) or high (6 kg/d; H-AMS) intake. Each period consisted of 28 d with 6 d for dietary transition, 13 d for adaptation, and 9 d of collection. The first 4 d of data and sample collection were used to evaluate behavioral data (milking frequency, feeding behavior, and standing and lying behavior) and ruminal pH. Subsequently, a sampling device removal day was provided, and the last 4 d were used to evaluate ruminal fermentation and apparent total-tract digestibility. All 9 d were used for milk yield measurement, and the 8 d were used for dry matter intake measurement. Cows fed the H-AMS consumed 3.5 kg/d less PMR while consuming 4.2 kg/d more AMS concentrate, but total dry matter intake (PMR+AMS) was not affected by treatments averaging 27.3 kg/d. Although cows fed H-AMS had greater concentrate intake, they also had greater variability for AMS concentrate intake among days (0.85 vs. 0.25 kg/d, respectively). The number of PMR meals and PMR eating behavior were not affected by the PMR or AMS treatments. Feeding H-AMS did not affect milking frequency averaging 3.63 milkings/d, but tended to increase milk yield by 1.25 kg/d relative to L-AMS. Likewise, cows fed the L-FOR tended to have greater milk yield relative to H-FOR (39.3 vs 37.9 kg/d, respectively), but had greater holding area time. Minimum ruminal pH tended to be lower for cows fed L-FOR compared with cows fed H-FOR but was not affected by the AMS concentrate treatment. When fed the L-FOR, feeding the H-AMS increased total short-chain fatty acid concentration in the rumen relative to cows fed L-AMS, whereas the response for H-FOR was not affected by the AMS concentrate. These data suggest that feeding H-AMS may improve milk yield, but also increases the day-to-day variability in AMS concentrate consumption. Feeding a L-FOR PMR may increase milk yield without affecting variability in AMS concentrate consumption; however, it may reduce ruminal pH and increase the time spent in the holding area compared with cows fed a H-FOR PMR.

Effect of a single dose of meloxicam prior to band or knife castration in 1-wk-old beef calves: I. Acute pain.

In Western Canada, approximately half of the calves produced are castrated before 1 wk of age. Therefore, it is important to identify effective analgesic drugs to mitigate pain associated with castration and consequently improve animal welfare. The aim of this study was to assess the efficacy of a single s.c. dose of meloxicam at mitigating pain associated with knife and band castration in 1-wk-old calves. Seventy-two Angus crossbred bull calves (47.3 ± 6.70 kg of body weight (BW), 1 wk old) were used in a 3 × 2 factorial design where main factors included castration method-sham (CT), band (BA) or knife (KN) castration- and medication-lactate ringer (NM) or 0.5 mg/kg BW of meloxicam (M). Measurements included different physiological and behavioral parameters. Samples were collected on day -1, immediately before castration (T0); and 60, 90, and 120 min and 1, 2, 3, and 7 d after castration except for visual analog scale (VAS) which was collected at the time of castration. The salivary cortisol concentrations were greater (P = 0.04) in KN and BA calves than CT calves 60 min after castration, while 90 min after castration BA had greater concentrations than CT calves. Substance P concentrations were greater (P = 0.04) in NM calves than M calves on d 3 and 7 after castration. The serum amyloid-A (SAA) concentrations were greater (P = 0.05) in KN calves than BA and CT calves on days 0, 2, and 3, while BA calves had greater SAA concentrations on day 7 than KN and CT calves. The visual analog scores were greater (P < 0.01) in KN calves than BA, and in BA compared to CT calves. The KN calves tail flicked more (P < 0.01) than BA and CT calves, and NM calves tail flicked more (P = 0.03) than M calves. No castration or medication effect (P > 0.10) was observed for stride length, walking, standing, lying ventral, eating, foot stamping, head turning, lying and standing percentage, performance, platelets, or body temperature. Overall, knife castrated calves exhibited a greater acute pain response than band castrated calves. Meloxicam was able to reduce substance P concentrations, white blood cell counts and number of tail flicks after castration, suggesting that the drug was able to mitigate acute pain to some extent. However, meloxicam did not have an effect on the other physiological and behavioral parameters assessed.

Effect of band and knife castration of beef calves on welfare indicators of pain at three relevant industry ages: II. Chronic pain.

Three experiments were conducted to evaluate the effects of band and knife castration on behavioral and physiological indicators of chronic pain in beef calves at 3 different ages (36 calves/age group): 1 wk of age (Exp. 1, 4 ± 1.1 d of age, 43 ± 1.1 kg BW), 2 mo of age (Exp. 2, 63 ± 2.3 d of age, 92 ± 1.7 kg BW), and 4 mo of age (Exp. 3, 125 ± 4.6 d of age, 160 ± 3.4 kg BW). In each experiment calves were randomly assigned to either sham (CT), band (BA) or knife (KN) castration. Experiments 1, 2, and 3 ended when the testicles of banded calves had sloughed off (68, 49, and 42 d, respectively). Animal BW and rectal temperature were recorded weekly over the experimental period. Salivary cortisol, substance P, haptoglobin, scrotal area temperature using infrared thermography, visual evaluation of swelling (5-point scale), and gait stride length were collected on d -1 and immediately before castration and weekly thereafter until the end of the study. Hair samples were collected 1 d prior to and 28 d after castration and at the end of the study for cortisol concentration. Standing and lying behaviors were recorded over a 28-d period immediately after castration. No differences ( > 0.10) were observed in salivary cortisol, substance P, haptoglobin, or hair cortisol among castration methods for any of the 3 ages. No changes in behavior were observed in calves castrated at 1 wk or 2 mo of age. In 4 mo-old-calves, BA spent less time lying ( < 0.01) than CT and KN calves. Also, the average duration of lying time for BA calves was greater ( < 0.05) than for CT calves. Both, 1-wk- and 2-mo-old calves had inflammation in the scrotal area lasting 7 d after KN castration, whereas inflammation was observed for up to 14 d in 4-mo-old calves. Swelling in BA calves lasted for 21 to 28 d in the 2 younger groups of calves, whereas in 4-mo-old calves swelling was observed until d 35 postcastration. Knife- and band-castrated calves did not exhibit indicators of chronic pain or distress when the procedures were performed in calves younger than 2 mo of age. Therefore, pain mitigation should be used when castrating to improve animal welfare, especially when castrations are performed in calves older than 2 mo of age independent of the method of castration.

Effect of band and knife castration of beef calves on welfare indicators of pain at three relevant industry ages: I. Acute pain.

Three experiments evaluated the effect of band and knife castration on acute pain for the first 7 d after the procedure on 1-wk-, 2-mo-, and 4-mo-old calves. All calves were blocked by age and weight and randomly assigned to 1 of 3 treatments: sham castration (control, CT), band castration (BA), and knife castration (KN). Experiment 1 evaluated 1-wk-old Angus bull calves ( = 34; 43.0 ± 6.61 kg BW), Exp. 2 evaluated 2-mo-old Angus bull calves ( = 34; 91.5 ± 11.93 kg BW), and Exp. 3 evaluated 4-mo-old Angus bull calves ( = 35; 157.6 ± 22.52 kg BW). For all experiments, physiological and behavioral parameters were collected before (d -1 and immediately before castration [T0]) and after (60 and 120 min and on d 7) castration to assess acute pain. Physiological measures included complete blood cell count, cortisol, substance P, and scrotal temperature. Behavioral measures consisted of a visual analog scale, stride length, and time and frequency budgets for walking, standing, lying, tail flicking, foot stamping, and head turning. Performance parameters included initial and final BW and ADG. In Exp. 1, tail flicking was greater ( = 0.02) in KN calves compared to BA calves 2 to 4 h after castration, although no differences were seen between BA and KN compared to CT calves. In Exp. 2, a treatment × time interaction ( = 0.02) was observed for cortisol, where KN calves had greater cortisol concentrations 120 min after castration compared to BA and CT calves; KN calves also lay down and ate less ( < 0.01; = 0.02) and stood and walked more ( < 0.01; = 0.05) compared to BA and CT calves 2 to 4 h after castration. In Exp. 3, a treatment × time interaction ( < 0.01) was observed for cortisol concentrations in which all treatments were different from one another at 60 and 120 min, with BA calves having the greatest concentrations, KN calves being intermediate, and CT having the lowest concentrations. Overall, KN and BA castrated calves presented physiological and behavioral changes associated with acute pain; however, 2-mo-old BA calves presented the fewest behavioral changes and no physiological changes associated with acute pain compared to CT calves.

Management practices associated with stress in cattle on western Canadian cow-calf operations: A mixed methods study.

Handling, weaning, and euthanasia are some of the most stressful practices performed on cow-calf operations. Although strategies to minimize stress exist, their use on western Canadian cow-calf operations is unknown. The objectives were to describe current stress-associated practices on western Canadian cow-calf operations, describe producer and operation demographics associated with the use of nonabrupt weaning methods, and explore producer perceptions toward these practices. A questionnaire focusing on stressful management practices was delivered to 109 cow-calf producers in western Canada. Fifteen respondents were purposively selected for individual interviews. The majority of producers reported calves less than 1 wk of age were handled by manual restraint (87%) and those older than 1 wk of age were handled using a cattle squeeze or table. Most producers performed abrupt weaning (70%). Interviewees often mentioned that cost and logistics were major factors in deciding on a weaning strategy. Pasture availability and facilities were viewed as constraints toward the adoption of a nonabrupt weaning method. Animal stress was considered, as producers expressed concern that nonabrupt weaning methods may cause increased stress because of the additional handling required. Producers conveyed that animal age was a major factor that impacted weaning stress and that improved animal performance might motivate them to adopt a nonabrupt weaning strategy. Producers also expressed reluctance to change previously successful traditional approaches. Of respondents, 13% did not euthanize cattle on farm and 8% did not confirm death. Producers interviewed reported that the decision to euthanize cattle on farm was difficult and that veterinary advice was often considered. Factors that influenced their decision to euthanize included the animal's likelihood of recovery and degree of pain and distress. Finally, producers explained that they considered whether the animal was salvageable and able to be transported. Identification of common methods of handling provides focus for future research to determine optimal handling strategies. Identified barriers to nonabrupt weaning may be addressed through research, extension, or policy to encourage the adoption of weaning methods that could improve animal welfare. Confirmation of death after euthanasia was identified as an area that needs to be addressed by producer education to minimize animal stress during on-farm euthanasia.

Effect of rest stop duration during long-distance transport on welfare indicators in recently weaned beef calves.

Forty newly weaned beef calves (260 ± 32.6 kg) were transported 15 h in a livestock trailer (7.3 by 2.1 m) on 2 separate hauls 1 wk apart (20 calves/haul) to evaluate the effect of rest stop duration on indicators of calf welfare. Immediately following the 15-h journey, 15 calves/haul were randomly unloaded at a feedlot and randomly assigned to 1 of 3 rest stop treatments; calves without resting time (5 calves/haul) remained on the trailer and were used as the control group. Treatments included 0- (Control [CON]), 5- (RS5), 10- (RS10), or 15-h (RS15) rest periods in pens containing ad libitum access to water and long-stem hay. Following each rest period, calves were reloaded onto the same trailer and taken on another 5-h journey, before they were unloaded at the same feedlot, for a total transport event lasting 20 h. Control calves did not have access to feed or water until the end of the 20-h transit event. Behavioral measurements included bunk attendance (min/d) and standing and lying duration (min/d) recorded for 5 h after the 20-h transport event. Physiological measurements included saliva and hair cortisol, complete blood cell count, serum NEFA, haptoglobin, and substance P concentrations. All physiological measurements as well as BW were taken immediately prior to initial loading, at arrival at the feedlot after the 20-h event, and 48 h after the transport to the same feedlot. Hair cortisol was collected prior to the initial loading and 25 d after transportation. No differences ( = 0.78) in BW loss were observed among treatments after transportation. Standing time was greater ( < 0.001) in CON calves compared with RS5, RS10, and RS15 calves. Salivary cortisol was greater ( < 0.01) in CON and RS15 calves than in RS5 and RS10 calves at the end of the 20-h journey. Serum NEFA concentration was greater ( = 0.03) in RS5 and RS10 calves at arrival compared with CON and RS15 calves, but those differences were no longer observed ( = 0.49) 48 h after transportation. Concentration of substance P did not differ ( = 0.18) between treatments, and haptoglobin concentration tended to be greater ( = 0.07) in CON calves compared with the other treatments 48 h after arrival. Hair cortisol tended ( = 0.10) to be lower in RS5 calves compared with the other treatments. The results of this study indicate that rest stop periods ≥ 10 h did not prevent short- and long-term stress after transport in weaned calves.

Management practices associated with pain in cattle on western Canadian cow-calf operations: A mixed methods study.

The implementation of on-farm pain mitigation strategies is dependent on feasibility and importance to producers. Currently, there is a lack of information regarding adoption of management practices associated with pain in cattle within the Canadian beef industry. The objective of this mixed methods study was to describe pain-associated practices implemented on farm and producer perceptions toward pain mitigation strategies. A questionnaire about calving management and calf processing was delivered to 109 cow-calf producers in western Canada. In addition, 15 respondents were purposively selected based on questionnaire responses to participate in individual semistructured, on-farm interviews. The prevalence of pain mitigation strategies used for dystocia and cesarean section by respondents were 46 and 100%, respectively. The majority of operations reported castrating and dehorning calves before 3 mo of age (95 and 89%, respectively). The majority of operations did not use pain mitigation strategies for castration and dehorning (90 and 85%, respectively). Branding was practiced by 57% of respondents, 4% of which used pain mitigation. Thematic content analysis revealed that producers' perception of pain were influenced by what they referred to as "common sense," relatability to cattle, visual evidence of pain, and age of the animal. Factors that influenced participant rationale for the implementation of pain mitigation practices included access to information and resources, age of the animal, benefit to the operation, cost and logistics, market demands, and personal conscience. Overall, management practices were generally in compliance with published Canadian guidelines. Results of this study may provide direction for future policy making, research, and extension efforts to encourage the adoption of pain mitigation strategies.

Effect of timing of subcutaneous meloxicam administration on indicators of pain after knife castration of weaned calves.

The newly revised Canadian Codes of Practice for the management of beef cattle requires that as of 2018, calves older than 6 mo of age be castrated using pain control. Castration is a husbandry procedure commonly done without pain control, and there is a lack of agreement on an effective pain mitigation strategy specific to castration. The aim of this study was to identify the optimal time of administration of meloxicam prior to castration. Thirty-four Angus and Angus crossbred bull calves (282 ± 28.0 kg BW) were randomly assigned to 1 of 3 treatments receiving a single s.c. injection of meloxicam (0.5 mg/kg BW): 6 h (6H; = 11), 3 h (3H; = 12), or immediately (0H; = 11) before knife castration. Measurements included visual analog scale (VAS), head movement (HM), accelerometer movement (AM) and strain gauge exertion force (EF) on the squeeze chute, stride length (SL), lying and standing behavior, salivary cortisol (SC), haptoglobin, serum amyloid A (SAA), substance P (SP), and scrotal temperature (ST). Samples were collected on d -7, -5, -2, -1, and immediately before castration (T0) and 30, 60, 120, and 240 min and 1, 2, 5, 7, 14, 21, and 28 d after castration, except for VAS, AM, EF, and HM, which were obtained at the time of castration. A time × treatment effect ( = 0.01) was observed for SP, where 0H had lower concentrations than 3H and 6H calves 1 d after castration, whereas 3H calves tended to have greater levels than 6H calves 5 d after castration. Mean ST was greater ( < 0.01) in 6H calves compared to 0H and 3H calves 120 min after castration, whereas 6H and 3H calves had greater ST compared to 0H calves 240 min after castration. On d 1 after castration, 6H calves had greater ST than 0H and 3H calves, whereas 0H calves had greater ST compared to 3H and 6H calves on d 28 after castration. The SL tended ( = 0.09) to be shorter in 3H and 6H calves than 0H calves 30, 60, 120, and 240 min after castration. Number of peaks from the AM between 2 and 3 SD above or below the mean were greater ( = 0.03) in 3H and 6H calves than in 0H calves. No treatment differences ( > 0.10) were observed for the number of peaks and area for AM and EF, VAS, HM, SC, or haptoglobin. On the basis of these results, the optimal time to administer s.c. meloxicam in 7- to 8-mo-old knife-castrated calves is immediately before castration (0H), as evidenced by fewer indicators of pain and inflammation compared to 3H and 6H calves.

Trailer temperature and humidity during winter transport of cattle in Canada and evaluation of indicators used to assess the welfare of cull beef cows before and after transport.

The current study evaluated 17 loads of cull beef cows transported in Canadian winter conditions to assess in-transit temperature and humidity, evaluation of events during loading and unloading, and animal condition and bruising. Regardless of the use of boards to block ventilation holes in trailers, temperatures were higher within trailers than at ambient locations during both travel and stationary periods (P < 0.01). Boarding was associated with smaller differences in trailer temperature, compared with ambient conditions, while the trailer was traveling at highway speeds versus when trailers were stationary (P < 0.01). Moisture levels within trailers were not different from ambient conditions when loads using boarding were traveling (P < 0.01), whereas loads without boarding had a larger difference (P < 0.01). The moisture within trailers relative to ambient conditions increased when trailers were stationary compared with traveling when boarding was used (P < 0.01). The majority of cattle transported were in good body condition (97.4% within BCS of 2 to 3.5) and had calm temperaments (96.7%). Although all comparisons were made, only the doghouse compartment had an increased risk of severe bruising compared with all other compartments (odds ratio [95% confidence interval]: 3.0 [1.6­5.5], 3.7 [2.1­6.4], 2.2 [1.3­3.7] and 3.8 [1.5­9.6] in comparison with the back, belly, deck, and nose compartments, respectively; P < 0.05). Increasing the duration of waiting to unload 30 min relative to a 1 h duration increased the odds of severe bruising by 1.18 times (95% confidence interval: 1.09­1.29; P < 0.01). Scoring systems that have been developed for auditing unloading of cattle had limited variation across loads at both loading and unloading. Pretransport assessment of animal condition using the American Meat Institute's compromised animal score was the only scoring system that was consistent with posttransport scores. We inferred from the temperature and humidity data in the current study that under commercial conditions, boarding may increase ventilation within trailers during travel and decrease ventilation during stationary periods. The current study provides the first indication that issues in Canadian cull cow transport may be related to pretransport animal condition and management of unloading.

Effect of grain type and processing index on growth performance, carcass quality, feeding behavior, and stress response of feedlot steers.

One hundred sixty crossbred steers (538 ± 36 kg BW) were used in an 84-d experiment with a randomized block design to study the effects of wheat or barley grain processed to 2 different indices on growth performance, feeding behavior, carcass characteristics, stress, and temperament of finishing beef cattle. Treatments were a wheat-based diet (88.4% of diet DM; WH) and a barley-based diet (89% of diet DM; BA), processed to an index of either 75% (HI) or 85% (LO) of their original volume weight. Cattle were allocated to 16 feedlot pens (10 animals per pen, 4 pens per treatment), 8 of which were equipped with the GrowSafe system for monitoring feeding behavior. Flight speed, hair, and saliva samples were collected on d 1, 28, 56, and 84 to determine temperament, acute, and chronic stress. All steers were slaughtered at the end of the experiment, and carcass quality was evaluated. Cattle fed WH had a lower (P < 0.05) meal length and frequency of visits per meal and tended (P = 0.10) to have a lower DMI, meal size, and feeding time than those fed BA. The LO processing index increased (P = 0.05) DMI and reduced (P < 0.05) the G:F and the percentage of saleable meat of the carcass compared to HI. There was a trend (P = 0.09) for a grain × processing index interaction, where cattle fed BA-LO had a lower incidence of severe liver abscesses compared with cattle fed other treatments. Cattle fed WH had greater hair cortisol concentrations (P = 0.01) and flight speed (P < 0.01) than those fed BA. There was a trend (P = 0.07) for a grain × processing index interaction, where heifers fed WH-LO had a lower salivary cortisol than those fed other treatments. Results suggest that a LO processing index had a negative effect on feed efficiency and carcass performance and that the WH diet caused a range of effects on feed intake and behavior indicative of steers with greater excitability and chronic stress.

Effect of anti-gonadotropin-releasing factor vaccine and band castration on indicators of welfare in beef cattle.

Angus crossbred bulls (n = 60; 257 ± 5.4 d of age; initial BW 358.8 ± 3.78 kg) were used to study the effect of a vaccine against gonadotropin-releasing factor (GnRF) and band castration on behavioral and physiological indicators of pain. Cattle were randomly assigned to 1 of 3 treatments: bulls, band-castrated calves without pain mitigation (castrated), and immune-vaccinated animals administered an anti-GnRF vaccine (vaccinated). All animals were fitted with a radio frequency ear tag so that individual animal feed intake and feeding behavior were recorded daily over the entire trial using an electronic feed bunk monitoring system. Two doses of anti-GnRF vaccine were administrated on d -35 and 0 and band castration was performed on d 0. Animal BW was recorded weekly starting on d -36 until d 56. Visual analog scores (VAS) were measured on d -36 -35, -1, and 0, and salivary cortisol concentration was measured at -30, 0, 30, 60, 120, and 270 min on d -35 and 0 after castration. Saliva and blood were obtained on d 1, 2, 5, and 7 and weekly until d 56 for determination of cortisol and complete blood cell count. Video data were collected for pain, sexual, and aggressive behavior daily the first week and once a week until d 56. Data were analyzed with a mixed-effect model with castration, time, and their interactions as main effects. Vaccinated calves had reduced ADG and intake (P < 0.05 and P < 0.001, respectively) during the first week after vaccination. Band-castrated calves had reduced ADG and intake (P < 0.001) until the end of the study. No differences in salivary cortisol and VAS were observed among groups at d -35 after the first vaccination and before band castration. However, on d 0, castrated cattle had greater cortisol concentrations and VAS (P < 0.05 and P < 0.01, respectively) than bulls and vaccinated animals. Complete blood cell count did not differ (P > 0.05) between treatments on d 0, 1, and 2. At d 56, vaccinated calves had greater (P < 0.05) final BW than band-castrated calves and both had less final BW than bulls. There was no indication that vaccination caused any physiological or behavioral changes indicative of pain. In contrast, band castration resulted in elevated cortisol scores and VAS indicative of a pain response and behavior related to pain (P < 0.001) until d 42 of the study. The present study demonstrates that anti-GnRF vaccine is a viable animal welfare-friendly alternative to traditional band castration in beef cattle under North American feedlot practices.

Feeding behavior as an early predictor of bovine respiratory disease in North American feedlot systems.

Bovine respiratory disease (BRD), which can cause substantial losses for feedlot operations, is often difficult to detect based solely on visual observations. The objectives of the current study were to determine a BRD case identification based on clinical and laboratory parameters and assess the value of feeding behavior for early detection of BRD. Auction-derived, mixed-breed beef steers (n = 213) with an average arrival weight of 294 kg were placed at a southern Alberta commercial feedlot equipped with an automated feed bunk monitoring system. Feeding behavior was recorded continuously (1-s intervals) for 5 wk after arrival and summarized into meals. Meals were defined as feeding events that were interrupted by less than 300 s nonfeeding. Meal intake (g) and meal time (min) were further summarized into daily mean, minimum, maximum, and sum and, together with frequency of meals per day, were fit into a discrete survival time analysis with a conditional log-log link. Feedlot staff visually evaluated (pen-checked) health status twice daily. Within 35 d after arrival, 76% (n = 165) of the steers had 1 or more clinical signs of BRD (reluctance to move, crusted nose, nasal or ocular discharge, drooped ears or head, and gaunt appearance). Whereas 41 blood samples could not be processed due to immediate freezing, for 124 of these steers, complete and differential blood cell count, total serum protein, plasma fibrinogen, serum concentration of haptoglobin (HP), and serum amyloid A (SAA) were determined. The disease definition for BRD was a rectal temperature ≥ 40.0°C, at least 2 clinical signs of BRD, and HP > 0.15 mg/mL. It was noteworthy that 94% of the 124 steers identified by the feedlot staff with clinical signs of BRD had HP > 0.15 mg/mL. An increase in mean meal intake, frequency, and mean inter-meal interval was associated with a decreased hazard for developing BRD 7 d before visual identification (P < 0.001). Furthermore, increased mean mealtime, frequency, and mean inter-meal interval were associated with a decreased BRD hazard up to 7 d before feedlot staff noticed clinical symptoms (P < 0.001). In conclusion, mean intake per meal as well as mean meal time and frequency of meals could be used to predict the hazard of BRD in feedlot cattle 7 d before visual detection and could be considered in commercial feedlot settings once a predictive algorithm has been developed.

Use of pattern recognition techniques for early detection of morbidity in receiving feedlot cattle.

Two groups of cattle were used to develop (model data set: 384 heifers, 228 ± 22.7 kg BW, monitored over a 225-d feeding period) and to validate (naïve data set: 384 heifers, 322 ± 34.7 kg BW, monitored over a 142-d feeding period) the use of feeding behavior pattern recognition techniques to predict morbidity in newly arrived feedlot cattle. In the model data set, cattle were defined as morbid (MO) if they were removed from their pen to be treated due to visual observation of clinical signs of bovine respiratory disease and healthy (HL) if they remained within their pen and lacked lung lesions at slaughter. Individual feeding behavior parameters collected with a GrowSafe automated feeding behavior monitoring system were reduced via principal component analysis to 5 components that captured 99% of the variability in the data set. Combinations of clustering and cluster classification strategies applied to those components, along with pattern recognition techniques over different time windows, produced a total of 105 models from which precision, negative predictive value, sensitivity, specificity, and accuracy were calculated by comparing its predictions with the actual health status of individual cattle as determined by visual assessment. When the models with the best specificity (models 79 and 87), sensitivity (models 33 and 66), and accuracy (models 3 and 14) in the model data set were used in a naïve data set, models 79 and 87 were not able to predict any MO heifers (0%), with all animals (100%) being predicted as HL. Model 33 predicted 58.3% of the HL and 66.7% of the MO heifers, with MO heifers identified 3.1 ± 1.64 d earlier than by visual observation. Model 66 predicted 50.0% of the HL and 75.0% of the MO heifers, with MO heifers predicted 3.1 ± 1.76 d earlier than by visual observation. Model 3 predicted 100% of the HL and 50.0% of the MO cattle, with MO cattle predicted 1 d earlier than by visual observation. Model 14 predicted 83.3% of the HL and 58.3% of the MO cattle, with MO cattle detected 2.4 ± 1.99 d earlier than visual observation. The application of pattern recognition algorithms to feeding behavior has potential value in identifying MO cattle in advance of overt physical signs of morbidity. Work on an integrated system that would automatically process data collected from automated feed bunk monitoring systems is still required, however, for this method to have value to the commercial feedlot industry as a practical means of identifying MO cattle in real time.

Trailer microclimate and calf welfare during fall-run transportation of beef calves in Alberta.

Twenty-four commercial loads of beef calves (BW 300 ± 52 kg, mean ± SD) were evaluated for associations among transportation factors, in-transit microclimate, and calf welfare. Transport factors evaluated included vehicle speed, space allowance, compartment within trailer, and transit duration. Calves were transported for 7 h 44 min ± 4 h 15 min, with space allowances ranging from 0.56 to 1.17 m(2)/animal. Compartment within trailer, space allowance, and vehicle speed did not affect the difference between compartment ceiling-level and ambient temperatures during a 30-min period of steady-state microclimate. During the steady-state period, a 1°C increase in ambient temperature above the mean of 5.6°C was associated with a 0.62°C decrease in the difference between ceiling-level and ambient temperature (P < 0.01). Ceiling-level temperature and humidity during the first 400 min of transport could be predicted by ambient conditions and vehicle speed (pseudo-r(2) of 0.91 and 0.82 for temperature and humidity ratio; P < 0.01). Events when animal-level temperature-humidity index (THI) was classified as above the "danger" level lasted for 10.2 ± 4.1 consecutive minutes. Ambient and ceiling-level THI values were not classified as above "danger" for 90.0 and 84.9% of animal-level events. Ambient and ceiling-level THI were 5.0 ± 2.1 and 4.7 ± 2.0° Flower than animal-level THI during periods of disagreement, respectively. The majority of calves arrived in good condition and biochemical indicators of calf welfare were within reference ranges for healthy cattle. Within the study population, high pre-transport cortisol and hematocrit were associated with elevated post-transport values (P < 0.01). A 1% increase in shrink during the weaning to loading interval (24 or 48 h) decreased transportation shrink by 0.26 ± 0.04% when average animal-level temperature was greater than 5°C and decreased transportation shrink by 0.11 ± 0.04% when average animal-level temperature was less than 5°C (P < 0.01). We inferred that the study results support future investigation of the extension of in-transit microclimate as a risk factor for post-transport treatment for disease. The study also provided correction factors for estimating in-transit microclimate that could assist in evaluation of transportation management and decisions affecting profitability and calf welfare.

Trailer microclimate during commercial transportation of feeder cattle and relationship to indicators of cattle welfare.

Nineteen loads of commercial feeder cattle (BW 376 ± 39 kg, mean ± SD) transported for 18 ± 4.5 h in summer and winter seasons were used to collect data on internal temperature and humidity conditions in the deck and belly compartment of pot-bellied trailers and their relationship with shrink, cortisol, and morbidity. Measurements of temperature or humidity at ceiling or animal level did not vary with transportation factors. Temperature and humidity ratio was greater at animal-level than ambient conditions during nonhighway travel and stationary periods (P < 0.01). During the 3 time periods evaluated within journeys, there was a larger difference between animal-level and ambient conditions during the winter than during the summer (P < 0.01); however, this difference was not associated with other transport factors (P > 0.05). Evening loads (1700 and 2100 h) experienced more shrink in the summer than in the winter (11.2 ± 0.5 vs. 9.0 ± 0.5% of BW; P = 0.03). A 1°C increase in difference between average animal-level temperature in transit and the mean ambient temperature during the 10 d before transport was associated with a 0.11 ± 0.03% of BW increase in shrink (P < 0.01) and 0.006 ± 0.002 ng/mL increase in posttransport cortisol concentration (P = 0.05). Animal-level temperature-humidity index (THI) events (consecutive observations of THI greater than 78°F) were more likely to last for longer than 1 h when the trailer was stationary vs. traveling (mean = 1.8, confidence level 95% = 1.33, 2.52). During THI events at animal level, the disagreement with ambient temperature regarding THI classification was lower when the vehicle was traveling vs. stationary (95.5 ± 0.01% vs. 99.7 ± 0.002% of THI event in disagreement; P < 0.01) and was greatest in events less than 1 h (99.8 ± 0.0% vs. 91.7 ± 0.03% of THI event in disagreement; P < 0.01). The average magnitude of the difference during these events was 11.4 ± 7.6°F and was not affected by transportation factors (P > 0.05). Despite association between indicators of calf welfare and microclimate, all cattle arrived in good condition and there was 0.96% treatment rate within the first 30 d after arrival. Management and auditing decisions related to transportation of feeder cattle should consider the relationship between animal-level and ambient conditions and conditions before transportation. Under the commercial conditions of the current study, the transportation process did not appear to cause distress according to the dimensions of animal welfare that were assessed.

Effects of castration method and frequency of intramuscular injections of ketoprofen on behavioral and physiological indicators of pain in beef cattle.

Two experiments were conducted to determine the effect of a single or multiple intramuscular (i.m.) injection of ketoprofen and castration technique on physiological and behavioral indicators of pain in beef calves. A total of 150 bull calves (284.8 ± 22.7 kg BW) were used in both experiments, each 1 conducted as a 3 × 2 factorial design, where main factors included castration technique--no castration (CT), surgical (SU), or band (BA)--and drug administration--physiological solution (PS) or i.m. injection of ketoprofen (KP; 3 mg Anafen/kg BW) in the neck of calves. Animals were weighed weekly during the experiment to calculate ADG. Behavioral responses indicative of pain and discomfort during the castration procedure were documented using a visual analog score (VAS) by an experienced observer who was blind to the treatments. Movements of the animals in the chute during castration were quantified using a strain gauge system mounted on the head gate to evaluate the escape response of the cattle. Pens were equipped with an automated feed bunk monitoring system enabling feed intake and feeding behavior to be continuously monitored for each individual. Thermographic images of the scrotal area were evaluated 24 and 0.5 h before castration, 0.5, 1, 24, 48, and 270 h postcastration, and weekly thereafter until the end of the trial. Blood samples were obtained postcastration to evaluate changes in total white blood cell (WBC) count and neutrophil-to-lymphocyte (N:L) ratio. Saliva samples were taken 24 and 0.5 h before castration, immediately after castration, and 0.5, 1, 2, 5, 24, and 48 h and then 5, 7, and 14 d after castration to determine cortisol concentration. Scrotal temperature, VAS, total WBC, N:L ratio, salivary cortisol, mobility, and pressure exerted in the chute were greater (P < 0.05) and ADG and feed intake were lower (P < 0.05) in SU than in CT animals within the first week after castration. Also, BA calves had a greater (P < 0.05) scrotal temperature around wk 4 after castration and a lower feed intake and ADG at wk 2 and 3 and wk 6 and 7 after castration, respectively, compared to CT. Treatment KP had limited effects on reducing the indicators of pain associated with SU or BA, suggesting that further studies will be needed to assess the posology of the i.m. administration of ketoprofen to improve the consistency of its effects as a pain mitigation strategy after castration.

Influence of environmental factors on infrared eye temperature measurements in cattle.

Environmental factors were evaluated to determine potential limitations in using cattle eye temperatures obtained through infrared thermography (IRT) for early disease detection systems or in animal welfare research studies. The effects of the following factors on IRT eye temperatures in cattle and a fabricated surrogate "eye" were evaluated: camera to object distance, wind speed, camera settings (distance, emissivity, and humidity), and solar loading. Wind speed in both live animals and using a surrogate "eye" was found to decrease the IRT temperature. In the presence of ∼ 7 km/h wind, the mean IRT eye temperature decreased by 0.43 ± 0.13 °C and; at higher wind speeds (∼ 12 km/h), the temperature decreased by 0.78 ± 0.33 °C. Direct sunlight was found to increase the IRT eye temperature by 0.56 ± 0.36 °C. It was determined that environmental factors impact IRT temperature measurements significantly and therefore must be managed to ensure reproducible and accurate readings.

Space allowance during commercial long distance transport of cattle in North America.

The objective of the present work was to study space allowance in cattle during commercial long haul transport (≥400 km; n = 6,152 journeys). Surveys, delivered to livestock transport carriers, gathered information on the number, BW, and distribution of cattle by trailer compartment as well as the characteristics of the transport vehicles used. Space allowance (SA; m(2)/animal), allometric coefficient (k = SA / BW(0.6667)), and the percentage of deviation from recommended SA (DRSA; %) in the Canadian Codes of Practice were calculated for each compartment of the trailers. All quad-axle (77%) and tri-axle (23%) cattle trailers were reported with 5 compartments (nose, deck, belly, back, and doghouse). Sixty percent of all animals were carried in the middle compartments (deck and belly), 30% in the rear (back and doghouse), and 10% in the front or nose. Approximately 30% of the journeys required that the cattle be redistributed at the Canada-USA border to comply with different axle weight regulations, and most journeys moved them between the deck and the doghouse. Total loaded weight increased and the number of animals decreased with increasing BW of the animals. space allowance, k-value, and DRSA were least for calves and feeders compared with fat and cull cattle (p < 0.01). Both total loaded weight and number of animals increased with the number of axles in the trailer, being greatest in quad-axle trailers pulled by push tractors, which were most frequently used. Space allowance (k-value) was least in vehicles with greater number of axles and transporting the lightest cattle (i.e., quad-axles trailers transporting calves and feeders). Space allowance, k-value, and variability among journeys were least in the middle compartments (belly and deck), followed by the back, then doghouse and nose compartments of the trailers showing the largest values (p < 0.05). Many factors contributed to the variability in SA such as body size (smaller animals are placed more densely), compartment of the trailer (greater density in belly and deck), and number of axles on the vehicle (greater density with more axles). The present study provides a framework to assess and understand factors affecting SA during commercial long distance transport of cattle. This information is vital in assessing the consequences of changing industry standards, guidelines, recommended values, laws and regulations on animal welfare, the industry, and economics.

Benchmarking study of industry practices during commercial long haul transport of cattle in Alberta, Canada.

The objective of the present study was to document current commercial practices during long haul transport (≥400 km) of cattle in Alberta through surveys delivered to truck drivers (6,152 journeys that transported 290,362 animals). The live beef export industry to the United States (89% of all journeys) had a large influence on long haul transport. This was particularly true for fat cattle going to slaughter (82%) and backgrounded feeders going to feed yards (15%). Most drivers had either limited (31% with < 2 yr) or extensive (35% > 10 yr) experience hauling cattle. The type of tractors and trailers used most frequently were those with more number of axles (quad-axle trailers pulled with push tractors) because they can accommodate extra weight. Mean (± SD) distance travelled was 1,081 ± 343 km (maximum of 2,560 km) whereas time animals spent on truck averaged 15.9 ± 6.3 h with a maximum of 45 h. However, only 5% of all journeys were greater than 30 h. The most frequent cause of delay was at the Canada-United States border crossing due to paperwork and veterinary inspections. Border delays occurred on 77% of all journeys which had a mean of 1.3 ± 1.9 h and up to 15-h long. Driver rest stops and waiting to unload cattle at destination were the second most frequent and longest cause of delay. Ambient temperature across all journeys ranged from -42 to 45°C with a mean value of 18 ± 11.8°C while temperature variation within a journey was from 0 to 46°C with mean value of 15 ± 6.6°C. The proportion of dead, non-ambulatory, and lame cattle for all journeys was 0.011, 0.022, and 0.011%, respectively. The cattle transport industry showed compliance with federal regulations and to a lesser extent with recommendations. Findings showed extreme values and very large variability in transport conditions however further research is needed to assess their impact on animal welfare outcomes. Delays within the journey as a result of border crossing, weather conditions, time on truck, shrink and space allowance may play an important role in improving cattle welfare during long haul transport.