Development and application of a scoring system for septum injuries in beef calves with and without a nose flap.

The weaning period is a stressful time for beef calves because they must quickly gain independence from their dam. Gradual methods of weaning, such as when the calf is fitted with a nose flap to prevent suckling, are known to reduce the behavioral and physiological indicators of stress. Nose flaps are held in place by the nasal septum and are worn for 4 to 7 d. In the present study, the objectives were to 1) identify if a plastic nose flap worn for 7 d caused nasal injuries, (2) identify if factors like calf body weight or septum size predict injuries or flap loss, and (3) create a scoring system that could reliably score wound characteristics. Eighty-two (N = 82) Angus and Angus-Hereford crossbred beef calves were randomly assigned to 'Flap' or 'No Flap' treatments. Calves weighed 247 ±â€…29 kg and those with a flap had septums that were 39 ±â€…2 mm (mean ±â€…SD). Images were taken of each nostril before flap insertion, on the day of removal, and 6 d after removal. Wounds were scored for the presence/absence of three characteristics in either nostril: damage (tissue where the flap rested was a different color than surrounding nostril), impression (edges of the wound were clearly raised or sunken), and blood. One trained observer scored a subset of photos (N = 64) twice, in a consistent manner for all three characteristics (damage, impression, and blood; 97%, 91%, and 100% agreement between 1st and 2nd evaluations, respectively), indicating that our system is repeatable. Thirty-two percent of calves in the Flap treatment lost their flap before the day of removal. No calves in the No Flap treatment were injured. All animals that kept their flap in for 7 d had damage and impressions in at least one nostril and 86% of calves had blood present immediately after nose flap removal (P ≤ 0.001 compared to No Flap) indicating that the flaps altered the nasal tissue and created open wounds. Six d after flap removal, 100% still had visible damage, 64% had impressions, and 29% had blood, indicating that while damage is longer lasting, wounds can start to repair after the flap is removed. Injuries were prevalent in all calves, thus there was no relationship between calf size (body weight or septum width) on these wounds (P ≥ 0.374). Body weight or septum size did not differ (P ≥ 0.489) between calves that kept or lost their flap. Injuries inflicted from a nose flap may counteract the previously documented benefits of this method of weaning, making it less advantageous than alternatives and raise concerns about other uses of these devices in other contexts.

Assessing effects of dietary and milking frequency changes and injection of cabergoline during dry-off on hunger in dairy cows using 2 feed-thwarting tests.

We investigated the single and combined effects of 2 feeding levels (normal lactation diet vs. energy-reduced diet, both fed for ad libitum intake) and 2 daily milking frequencies (twice vs. once) during 1 wk before the dry-off day (d 0), as well as an intramuscular injection of either a dopamine agonist (cabergoline; Velactis, Ceva Santé Animale; labeled for use only with abrupt dry-off, e.g., no reduction in feeding level or milking frequency before the last milking) or saline after the last milking on d 0 on the feeding motivation of clinically healthy, loose-housed, pregnant, lactating Holstein cows. From d 0, all cows were fed the same dry-cow diet for ad libitum intake. Cows were subjected to 2 feed-thwarting tests, a test in the home pen using their diets (test A: d -6, -1, and 1; during 35 min when the feed bins were filled, but locked) and another test carried out in an adjacent pen in which access to concentrate provided in a familiar plastic box was blocked by a wire-mesh lid (test B: d -5 and 2). In test A, we recorded how often cows attempted to feed per 35 min, whether cows vocalized during the 35-min period, and latency to feed within 300 s after feed bins were unlocked. In test B, we recorded latency to approach either of 2 familiar boxes (the wire-mesh box and an identical open box with a small portion of concentrate) within 600 s and how often cows directed behaviors toward the wire-mesh box (number of occurences/5 min). On d -6 (test A), no clear differences in feeding motivation among treatments were found. On d -5 and -1, cows fed the energy-reduced diet displayed a higher probability of vocalizing (test A), were more than 50% quicker to feed (test A), were approximately 5× quicker to approach a box (test B), and directed 60% more behavior toward the wire-mesh box (test B) than cows fed the normal diet. Moreover, cows fed the energy-reduced diet attempted to feed approximately 75% more on d -1 compared with d -6 (test A). On d 2 (test B), cows previously fed the normal diet directed 40% more behavior toward the wire-mesh box than cows previously fed the energy-reduced diet. Reducing feeding level, either before or on the dry-off day, resulted in consistently increased feeding motivation, interpreted as a sign of hunger. No clear effects of change in milking frequency, singly or combined with reduced diet energy density, on feeding motivation were found before d 0. Whereas, on d 2, cows previously milked twice daily were quicker to approach a box than cows previously milked once daily. Cows injected with cabergoline attempted to feed more, but showed lower probability of vocalizing compared with saline-injected cows (d 1; test A), irrespective of treatment before d 0. The effects of cabergoline on feeding motivation are not easily interpreted and warrant further investigation. From a hunger perspective, reducing milking frequency rather than diet energy density seems to be a less negative management to reduce milk production before dry-off.

Measuring behavior patterns and evaluating time-sampling methodology to characterize brush use in weaned beef cattle.

With growing interest in provision of brushes for cattle and the implications of brush use for behavioral development and welfare, there is a need to validate methodology for quantifying grooming behavior. Our objectives were to characterize patterns of brush use, including bouts, diurnal activity, and individual variability over 24-h periods, and to validate time-sampling methodologies to characterize these traits, including instantaneous recording at various time intervals and continuous recording for subsets of the day. Data sets from previous experiments involving steers (experiment 1; n = 18) and heifers (experiment 2; n = 64), consisting of start and end times of brush use continuously recorded from video, were used to analyze brush use. We extrapolated data sets representative of a range of instantaneous recording intervals and compared daily brush duration and bout characteristics with corresponding values from continuous recording using linear regression. To assess validity of sampling subsets of the day, we selected 2-h time periods representative of different functional parts of the day and compared hourly brush rates with continuous data using Spearman's rank order correlation (rs). Brush use was variable among individuals. All steers used the brush in experiment 1, but 17% (n = 11 of 64) of heifers in experiment 2 did not. Bout analysis revealed that individuals used the brush for an average of 7 to 8 brush bouts lasting 4 to 6 min, leading to an average of 24 and 36 min/d for experiments 1 and 2, respectively. Cattle used the brush mainly during daylight hours, with peaks around sunrise, sunset, and the afternoon. Instantaneous recording at intervals less than 1 to 3 min, depending on the experiment, provided good estimates of daily brush use duration (R2 > 0.95 and slope and intercept not different from 1 and 0, respectively), but intervals >3 min were less reliable. For bout characteristics, the intercept of the modeled line differed from 0 for most recording intervals for both experiments, and the slope differed from 1 for recording intervals >30 s in experiment 1, suggesting that time sampling may have underestimated true values. Of the 2-h periods compared with 24 h of observation, 1800 to 2000 h was most highly correlated (rs = 0.84) for experiment 1, and 1800 to 2000 h and 1400 to 1600 h were the most highly correlated (rs = 0.71 and 0.74, respectively) for experiment 2 with daily values. When using time-sampling methods to characterize brush use, we suggest that the recording interval used and time of day observed should be carefully considered, as time sampling at an interval of 1 to 3 min may measure daily brush use duration, but continuous recording may be required to capture bout characteristics.

Effects of 3 surface types on dairy cattle behavior, preference, and hygiene.

Muddy surfaces have negative effects on the health and welfare of dairy cattle, and if possible, cows will avoid this surface. However, it is unclear whether it is the moisture content or the contamination with manure that is aversive to the cows. This study aimed to assess the use and preference for different wood chip (0.4 m deep) surface types: (1) clean and dry (clean, dry matter content, DM: 44 ± 2.8%), (2) dirty (dirty, contaminated with manure, DM: 40 ± 3.7%), and (3) clean and wet (wet, wetted by water, DM: 23 ± 3.3%). Eighteen nonlactating, pregnant cows were tested individually (mean 24-h temperature: 9.9 ± 4.46°C, mean ± standard deviation for all preceding values). Cows were kept indoors in test pens for 18 h on wood chip without feed and 6 h on pasture to allow for daily feed intake. To ensure cows made informed choices and to measure changes in behavior and hygiene associated with each option, they were first exposed to each surface for 5 d (n = 12 cows per surface type when they were restricted on one surface; i.e., each cow was exposed to 2 treatment surfaces only). Cows on the wet surface spent the least amount of time lying when restricted to one surface for 18 h (wet: 21%, dirty: 57%, clean: 64%) and spent more time lying when on pasture for 6 h (wet: 13%, dirty: 4%, clean: 3%). The total lying times during the 5-d surface exposure were wet: 4.6 ± 1.04 h, dirty: 10.6 ± 0.25 h, and clean: 11.7 ± 0.25 h per 24 h. Cows restricted on the wet surface for 18 h had fewer bouts (no.) of lateral lying (wet: 0.9 ± 1.36, dirty: 6.3 ± 1.36, clean: 8.4 ± 1.38), spent less time lying with their heads supported (wet: 18.9 ± 7.17 min, dirty: 36.7 ± 7.17 min, clean: 39.1 ± 7.26 min), and spent less time with the front legs tucked (wet: 16 ± 4.3%, dirty: 41 ± 4.3%, clean: 50 ± 4.3% of time spent lying, mean ± standard error of the mean for all preceding values), than cows on the other surfaces. Cows on the dirty surface were less clean compared with the other treatment groups (0.6 of a score on a 5-point scale; standard error of the differences of means: 0.11 for both comparisons). They were then given a free choice between 2 known surfaces for 2 consecutive days (n = 6 per pairwise choice). Cows ranked the surfaces as clean > dirty > wet. In summary, there is compelling evidence that wet surfaces impair the welfare of dairy cattle by affecting the quantity and quality of rest. Rebound responses indicate that the motivation to rest is not fulfilled on wet surfaces. Finally, when given a choice, they show clearly that they will avoid wet and dirty surfaces. The combined results indicate that changes in affective state likely underlie these behavioral responses.

Fever, feeding, and grooming behavior around peak clinical signs in bovine respiratory disease.

Feedlot cattle are monitored for the sickness response, both physiological and behavioral, to detect bovine respiratory disease (BRD), but this method can be inaccurate. Diagnostic accuracy may improve if the BRD sickness response is better understood. We hypothesized that steers around peak BRD would have fever, anorexia, and less grooming than controls. We also expected sickness response magnitude to be greater as clinical and pathological severity increased. Unvaccinated steers were assigned to challenge with 1 of 5 BRD viruses or bacteria (BRD challenge; = 4/pathogen; 20 total), based on susceptibility as determined by serology. Body weight-matched vaccinated animals were given sterile media (Control; = 4/pathogen; 20 total) and housed by treatment (5 pens/treatment). Rectal temperature was logged every 5 min between 0100 and 0700 h, and time spent feeding (24 h/d), in contact with a brush (13 h/d), and self-licking (24 h/d) were collected from video recordings. Steers were examined and a clinical score (CS) was assigned daily. Bovine respiratory disease challenge steers were euthanized after 5 to 15 d (timing was pathogen specific) and the proportion of grossly affected lung (%LUNG) was recorded. The day of highest CS (peak; d 0) for each BRD challenge steer and the 2 preceding days were analyzed for all variables except self-licking (d 0 only); analogous days were included for Controls. Penwise mixed models (pen was the experimental unit) were used to determine which sickness response elements differed between treatments before and at peak disease, and regression using individual-steer data was used to describe relationships between disease severity ( = 35 for CS and = 20 for %LUNG) and fever, anorexia, and grooming. Bovine respiratory disease challenge steers had fever (1.1°C higher; < 0.01) and anorexia (35% lower feeding time; = 0.03) but did not differ from healthy Controls for brush contact ( = 0.37) or self-licking ( = 0.15). Higher CS and more %LUNG were associated with increased fever (d 0; ≤ 0.04) and lower feeding (d 0; < 0.01), brush contact (d 0; ≤ 0.03), and self-licking ( ≤ 0.05) duration relative to lower CS and less %LUNG. In conclusion, fever and feeding time are good BRD diagnostic measures around peak CS. Further study is needed to clarify why grooming was not a good measure. The sickness response is greater as BRD severity increases; fever is most closely related to CS and anorexia is most closely related to %LUNG. Regardless of which aspect is monitored, cattle with milder disease may be more difficult to detect than sicker animals.

Assessing cow-calf welfare. Part 1: Benchmarking beef cow health and behavior, handling; and management, facilities, and producer perspectives.

Assessment programs are one way beef producers communicate information about animal welfare to retailers and the public. Programs that monitor cattle through the production cycle (e.g., the Global Animal Partnership) or at individual stages (e.g., slaughter; the North American Meat Institute) exist, but to date, there is no assessment program addressing welfare specifically in the cow-calf sector. The objectives of this study were to measure cow-calf health and handling welfare outcomes and gather management, facility, and producer perspective information to 1) describe current practices and 2) inform assessment design. A welfare assessment, designed using features of similar beef and dairy programs, was conducted on 30 California ranches that varied in size (mean 1,051 cows [SD 1,849], range 28 to 10,000 cows) and location within the state. Cattle health and behavior and stockperson handling were measured during a routine procedure (e.g., pregnancy checks) on breeding females ( = 3,065). Management and producer perspectives were evaluated through an interview, and facility features were recorded at the chute and water access points. Cattle health problems were rare and seen only on specific ranches (e.g., prevalence of lame cattle: mean 1.3% [SD 1.5], range 0 to 7.1%). Cattle behavior and stockperson handling varied between ranches (e.g., cattle balking: mean 22.0% [SD 21.9], range 1.6 to 78.3%; electric prod use: mean 23.5 [SD 21.5], range 0 to 73.0%). Although some management and facility characteristics were shared by most (e.g., all ranches castrated bull calves; 86% used alleyways with an anti-back gate), other aspects varied (e.g., weaning age: mean 8.2 mo [SD 1.4], range 6 to 11 mo; 43% used shade cover over chute). Most producers shared similar perspectives toward their herd health management plan, but their responses varied when asked to evaluate an animal's pain experience. In terms of assessment design, there were challenges with feasibility (e.g., scheduling a ranch visit on a day cattle were processed was difficult), validity (e.g., cattle may back up calmly to adjust posture or quickly in response to an aggressive handler; without this context, the welfare implications of this behavior are unclear), and comparability (e.g., an explicit animal observation period needed to be defined to make comparisons across ranches). Future assessment programs should consider these qualities when selecting measures to evaluate welfare.

Assessing cow-calf welfare. Part 2: Risk factors for beef cow health and behavior and stockperson handling.

Epidemiological studies can be used to identify risk factors for livestock welfare concerns but have not been conducted in the cow-calf sector for this purpose. The objectives of this study were to investigate the relationships of 1) herd-level management, facilities, and producer perspectives with cattle health and behavior and stockperson handling and 2) stockperson handling on cattle behavior at the individual cow level. Cow ( = 3,065) health and behavior and stockperson handling during a routine procedure (e.g., pregnancy checks) were observed on 30 California ranches. Management and producer perspectives were evaluated using an interview, and handling facility features were recorded at the chute. After predictors were screened for univariable associations, multivariable models were built for cattle health (i.e., thin body condition, lameness, abrasions, hairless patches, swelling, blind eyes, and dirtiness) and behavior (i.e., balking, vocalizing, stumbling and falling in the chute and while exiting the restraint, and running out of the restraint) and stockperson handling (i.e., electric prod use, moving aid use, tail twisting, and mis-catching cattle). When producers empathized more toward an animal's pain experience, there was a lower risk of swelling (odds ratio [OR] = 0.7) but a higher risk of lameness (OR = 1.3), which may indicate a lack of awareness of the latter. Training stockpersons using the Beef Quality Assurance program had a protective effect on cow cleanliness and mis-catching in the restraint (OR = 0.2 and OR = 0.5, respectively). Hydraulic chutes increased the risk of vocalizations (OR = 2.7), possibly because these systems can apply greater pressure to the sides of the animal than manual restraints. When a moving aid was used to move an individual cow, it increased the risk of her balking, but when hands, in particular, were used, the risk of balking decreased across the herd (OR = 34.1 and OR = 0.3, respectively). Likewise, individual cows were at a greater risk of balking, vocalizing, stumbling and falling in the chute, and stumbling and running at exit when they were touched with an electric prod (OR = 11.0, OR = 3.3, OR = 1.9, OR = 2.3, OR = 1.8, and OR = 1.7, respectively). Although the implications of using moving aids are unclear, reducing the use of electric prods could improve cattle handling. In conclusion, cattle handling was influenced by a number of facility and stockperson factors: personnel training, facility design, and electric prod use are key areas for future improvements.

Shade use by small groups of domestic horses in a hot, sunny environment.

Horses in the United States are commonly managed in outside pens or pastures in small groups. Limited research on shade use by domestic horses housed singly in individual pens has shown benefits and a preference for using available shade. The objective of this study was to examine the amount of shade use and the behavioral and physiological responses of small groups of horses when housed with access to shade (SH) and without access to shade (SUN). Thirty-six horses were randomized into 3 consecutive trials using 3 horses per group and 4 groups per trial. Groups experienced 5 d in each treatment in a crossover design. Weather factors were measured with automated sensors 24 h/d throughout the study. The mean afternoon ambient temperature was 31.0°C with relative humidity of 32%. Rectal temperature, respiration rate, and skin temperature were recorded at 1000, 1330, and 1900 h daily. Venous blood samples were obtained on Days 0 and 5 to measure serum cortisol, the neutrophil:lymphocyte ratio, and hematocrit. Behavioral observations for presence in shade, standing near or away from water, locomotion, and foraging were recorded at 5-min intervals from 1400 to 1900 h daily. Insect avoidance behaviors were recorded hourly during that same time period for 1 min/horse. Horses in the SH treatment were observed using shade in 7.1% of observations between 1400 and 1900 h, and behavioral differences were observed between the SH and SUN treatments. When in the SUN treatment, horses stood near the water troughs more (18.5 vs. 14.2% of observations; = 0.029) and foraged less (29.3 vs. 33.8% of observations; < 0.001) than when in the SH treatment. There were no treatment differences for other behaviors or for physiological measures ( > 0.05). Provision of shade structures accessible to groups of mature, healthy horses in hot, sunny environments should be considered in developing future guidelines for best management practices for horses.

Stepping behavior and muscle activity of dairy cows on uncomfortable standing surfaces presented under 1 or 4 legs.

The comfort of dairy cattle while standing has important implications for housing design. Research has examined how cattle respond to standing surfaces by presenting options under all 4 legs or under a single leg, but no work, to date, has compared presentation methods. This study examined behavior and muscle activity when cows stood on rough floors under all 4 legs or just 1 hind leg. Three treatments were tested: smooth concrete under all 4 legs (0-ROUGH), a rough surface under all 4 legs [2cm × 2cm × 4cm trapezoidal protrusions (4-ROUGH)], and a rough surface only under 1 hind leg, with other legs on smooth concrete (1-ROUGH). Twenty-four healthy Holstein cows stood on each surface for 1h/d in a repeated-measures design. Surface electromyograms (SEMG) were used to evaluate muscle fatigue and total activity. Muscle fatigue was measured using SEMG to evaluate (1) static contractions when cows were continuously weight bearing on each hind leg, before and after 1h of standing, and (2) dynamic contractions associated with steps during 1h of standing. Behavioral measures included steps per minute, time between each consecutive step, and the latency to lie down after testing. The number of legs affected by roughness influenced both behavioral and physiological responses to flooring. Cows on 1-ROUGH stepped twice as often with the rough-treated leg and one-half as much with the hind leg on smooth concrete compared with other surfaces. Similarly, on the 1-ROUGH surface, total muscle activity was reduced in the leg on the rough surface, and muscle activity was more sustained (3× higher) in the other hind leg, suggesting that cows avoid possible discomfort under 1 leg by using muscles in the other. In the 4-ROUGH treatment, time between steps was more variable than on the other 2 treatments (coefficient of variation, 4-ROUGH: 245; 1-ROUGH: 208; 0-ROUGH: 190±5.8%), likely because cows could not move away from this uneven flooring. Thus, the method of presentation of stimuli used to evaluate comfort while standing altered the response. Stepping rate and SEMG changed when roughness was under a single leg, whereas timing between consecutive steps was more variable with rough flooring under all 4 legs. These results have implications for the design of experiments evaluating standing comfort in the future.

Pain sensitivity and healing of hot-iron cattle brands.

Hot-iron branding is painful for cattle, but little is known about the duration of or effective methods to control this pain. This work quantified pain sensitivity and healing in branded and unbranded animals. In addition, the effects of a single injection of nonsteroidal anti-inflammatory drug (NSAID) were also considered; this has been suggested as practical method of mitigating pain in the hours after the procedure. Calves (mean±SE, 126±2.2 d and 112±2.8 kg) were hot-iron branded and allocated to 1 of 4 treatments: branded with or without flunixin meglumine (intravenous; 1.1 mg/kg) and unbranded with or without this NSAID (n=12/treatment). Pain sensitivity was assessed by applying a known and increasing force with a von Frey anesthesiometer in the center of the brand (or equivalent area in nonbranded treatments) until animals showed a behavioral response. Healing was measured with a 6-point scale (1=fresh brand and 6=no scabbing and fully repigmented). These measures, along with weight gain and surface temperature, were recorded 1, 2, 7, 14, 21, 28, 35, 42, 56, and 71 d after branding. Lying behavior was recorded with loggers from the day before to d 27 after branding. Brand wounds were more painful than nonbranded tissue (P<0.001). These differences were most pronounced in the days immediately after branding (e.g., d 7; 113±36 g of force for Brand vs. 449±23 g force for No brand, mean±SE) but persisted until d 71 (380±37 g force for Brand vs. 453±23 g of force for No brand, mean±SE); only 67% of brands were fully regimented or healed by this time. The first fully healed brand was identified 8 wk after the procedure. Giving a single injection of flunixin had no brand-specific effects on sensitivity, surface temperature, or healing but improved weight gain in the days after branding in all treated groups (flunixin×brand×day, P<0.001). Flunixin-treated animals also spent 0.7 h less time lying down on the day of branding but tended to spend more time lying on d 15 and 26 after the procedure. The magnitude of these differences is small, less than the day-to-day variation, and not brand specific. In summary, brand wounds take at least 8 wk to heal. These wounds remain painful for a least this long, and a single injection of NSAID has no measurable effect in mitigating pain associated with branding, even in days immediately after the procedure.

Effect of a cooling gel on pain sensitivity and healing of hot-iron cattle brands.

Hot-iron branding is painful for cattle, but little is known about how long this pain lasts or effective alleviation methods. Previous work with pigs indicated that cooling burns with a gel (active ingredient: tea tree oil) improved healing compared to untreated wounds. Steers (210±21 kg) were hot-iron branded and allocated to 1 of 3 treatments: control (n=24), 1 gel application immediately after branding (1X; n=12), or 2 gel applications, 1 immediately after branding and one 1 d later (2X; n=12). Pain sensitivity was assessed by applying a known and increasing force with a von Frey anesthesiometer in 5 locations (in the center, at the top of, and 5 and 10 cm above the brand and on the equivalent location on the nonbranded side of the body) until animals showed a behavioral response. Healing was measured with a 6-point scale (1=fresh brand and 6=no scabbing and fully repigmented). Both measures, along with weight gain and surface temperature of the wound, were recorded before and 1, 2, 3, 7, 14, 21, 28, 35, 56, and 70 d after branding. The gel cooled the brand, with the most obvious differences on the day it was applied (3.7 to 4.2°C cooler than control; day×gel interaction, P=0.004). All wounds were at least partially repigmented by 70 d, but only 46% of brands were fully healed at this time. The healing process was slowed when a gel was applied twice (e.g., at 21 d, healing score of 2.5±0.1 and 2.7±0.1 vs. 2.0±0.2 for control and 1X vs. 2X, respectively; P=0.001). Brands tended to remain painful throughout the 70 d (in the center of the brand; before vs. d 1-35, P≤0.001; d 56, P=0.058; and d 70, P=0.092). Overall, gel had little effect on pain sensitivity. Weight gain was reduced on d 1 after branding compared to all other time points (P<0.001) but was not affected by gel application (P=0.277). In conclusion, applying gel did not improve outcomes after branding. In addition, by 70 d after the procedure, hot-iron brands still tended to be more painful than nonbranded tissue and 54% were not fully healed. These results raise additional animal welfare concerns about hot-iron branding.

Healing of surgical castration wounds: a description and an evaluation of flunixin.

Previous studies have shown that surgical castration wounds take between 10 and 61 d to heal. The objectives of this work were to describe healing, inflammation, lying behavior, and serum concentration of substance P after surgical castration in beef calves and to evaluate the effect of a possible intervention, a single injection of flunixin meglumine (1.1 mg/kg IV, a NSAID), on the healing process. Calves (mean±SE: 25±2.0 d of age; 54±1.4 kg BW) were surgically castrated with or without an injection of flunixin immediately before the procedure (n=24/treatment). Healing was measured with a 5-point scale (1=fresh wound, 5=no visible incision or inflammation) as well as weight gain, scrotal size, and scrotal surface temperature, on d 1, 2, 3, 7, 14, 21, 28, 35, 49, and 63 after castration. Serum concentration of substance P was recorded on all d, including d 0, but not d 63. Lying behavior was recorded with loggers from 2 d before to 29 d after castration. Inflammation, as measured by scrotal size, peaked on d 2 and 3 after the procedure (e.g., 51±1.0 mm on d 2 versus 28±1.3 mm before castration) and then declined with time (P<0.001). The first wound to score as fully healed (i.e., 5/5) was seen on d 28; by d 63, 98% of wounds were fully healed. The greatest changes in healing score occurred between d 21 and 35; this was also the peak of wound surface temperature and may correspond with revascularization. Serum concentration of substance P was highest before castration (41±1.2 pg/mL), possibly because the sample was collected after the lidocaine ring block was administered, which was likely painful, and because of separation from the dam and restraint. Values began to drop by d 3 (34±1.2 pg/mL) and leveled out by d 21 (30±1.2 pg/mL; P<0.001). Calves given flunixin had more lying bouts than those that received saline (flunixin by time interaction; P=0.052), but this pattern emerged on and after d 8, well after the 3 to 8 h half-life of this NSAID. In conclusion, castration caused inflammation in the days that followed, and the wounds required a minimum of 4 wk to heal. Provision of an NSAID had no effect on these outcomes.

A field study of the behavioral and physiological effects of varying amounts of shade for lactating cows at pasture.

Shade reduces the negative effects of heat load, but little is known about how much is required for efficient cooling in commercial settings. The effect of the amount of shade on 8 Holstein-Friesian herds was studied for 2 consecutive summers (mean temperature: 23 °C) on 6 commercial, pasture-based dairy farms. Farms varied in the amount of natural shade provided (range: 0 to 15.6m(2) shade/cow). Time spent in shade, near water, eating, ruminating, lying, and standing were recorded between 1000 and 1530 h in 31 shaded and 11 unshaded paddocks using 20-min instantaneous scan observations of 15 focal cows/herd. Respiration rate and panting score (0 to 4.5) was recorded for focal animals once per hour. The total numbers of cows in shade, near water, and with panting scores ≥ 2 were recorded every 30 min. Cows without shade spent 4% more time lying than cows with shade (standard error of the difference, SED = 1.9%). A larger proportion of the herd had panting scores ≥ 2 when no shade was available (6 vs. 2% of the herd, SED = 1.2%), and respiration rates were higher by 8 breaths/min in cows without shade (SED = 4.7 breaths/min). Under the conditions tested, the maximum proportion of the herd that was observed using the shade increased by 3.1% for every 1-m(2) increase in shade size [standard error (SE) = 1.51%], and all cows were first seen simultaneously using shade when 2m(2)/cow was provided. For every 1-m(2) increase in shade, 0.3% fewer cows had panting score ≥ 2 (SE = 0.12%). We observed no significant relationships between the amount of shade available and any other variables. Although additional work is required to make specific recommendations, these results indicate that providing more shade allowed a higher proportion of animals to use this resource and reduced respiratory signs of heat load.

How do cattle respond to sloped floors? An investigation using behavior and electromyograms.

On dairy farms, flooring is often sloped to facilitate drainage. Sloped floors have been identified as a possible risk factor for lameness, but relatively little is known about how this flooring feature affects dairy cattle. Ours is the first study to evaluate the short-term effects of floor slope on skeletal muscle activity, restless behavior (measured by number of steps), and latency to lie down after 90 min of standing. Sixteen Holstein cows were exposed to floors with a 0, 3, 6, or 9% slope in a crossover design, with a minimum of 45 h between each testing session. Electromyograms were used to evaluate the activity of middle gluteal and biceps femoris muscles. Muscle activity was evaluated in 2 contexts: (1) static muscle contractions when cows continuously transferred weight to each hind leg, before and after 90 min of standing; and (2) dynamic contractions that occurred during 90 min of treatment exposure. Median power frequency and median amplitude of both static and dynamic muscle electrical signals were calculated. Total muscle activity was calculated using the root mean square of the signals. Restless behavior, the number of steps per treatment, steps and kicks in the milking parlor, and the latency to lie down after the test sessions were also measured. It was predicted that restless behavior, muscle fatigue (as measured by median power frequency and median amplitude), total muscle activity, and latency to lie down after testing would increase with floor slope. However, no treatment differences were found. Median power frequency was significantly greater for the middle gluteal muscle [35 ± 4 Hz (mean and SE)] compared with the biceps femoris muscle (24 ± 3 Hz), indicating that the contractive properties of these muscles differ. The number of steps per minute and total muscle activity increased significantly over 90 min of standing, irrespective of floor slope. Although restless behavior and muscle function did not change with slope in our study, this work demonstrates that electromyograms can be used to measure skeletal leg muscle activity in cattle. This technology, along with restless behavior, could be useful in assessing cow comfort in other situations, such as prolonged standing.

Evaluation of the sample needed to accurately estimate outcome-based measurements of dairy welfare on farm.

Dairy welfare assessment programs are becoming more common on US farms. Outcome-based measurements, such as locomotion, hock lesion, hygiene, and body condition scores (BCS), are included in these assessments. The objective of the current study was to investigate the proportion of cows in the pen or subsamples of pens on a farm needed to provide an accurate estimate of the previously mentioned measurements. In experiment 1, we evaluated cows in 52 high pens (50 farms) for lameness using a 1- to 5-scale locomotion scoring system (1 = normal and 5 = severely lame; 24.4 and 6% of animals were scored ≥ 3 or ≥ 4, respectively). Cows were also given a BCS using a 1- to 5-scale, where 1 = emaciated and 5 = obese; cows were rarely thin (BCS ≤ 2; 0.10% of cows) or fat (BCS ≥ 4; 0.11% of cows). Hygiene scores were assessed on a 1- to 5-scale with 1 = clean and 5 = severely dirty; 54.9% of cows had a hygiene score ≥ 3. Hock injuries were classified as 1 = no lesion, 2 = mild lesion, and 3 = severe lesion; 10.6% of cows had a score of 3. Subsets of data were created with 10 replicates of random sampling that represented 100, 90, 80, 70, 60, 50, 40, 30, 20, 15, 10, 5, and 3% of the cows measured/pen. In experiment 2, we scored the same outcome measures on all cows in lactating pens from 12 farms and evaluated using pen subsamples: high; high and fresh; high, fresh, and hospital; and high, low, and hospital. For both experiments, the association between the estimates derived from all subsamples and entire pen (experiment 1) or herd (experiment 2) prevalence was evaluated using linear regression. To be considered a good estimate, 3 criteria must be met: R(2)>0.9, slope = 1, and intercept = 0. In experiment 1, on average, recording 15% of the pen represented the percentage of clinically lame cows (score ≥ 3), whereas 30% needed to be measured to estimate severe lameness (score ≥ 4). Only 15% of the pen was needed to estimate the percentage of the herd with a hygiene score ≥ 3, whereas 30% to estimate the prevalence of severe hock lesions. Estimating very thin and fat cows required that 70 to 80% of the pen be measured. In experiment 2, none of the pen subsamples met our criteria for accurate estimates of herd prevalence. In conclusion, we found that both a higher percentage of the pen must be sampled to generate accurate values for relatively rare parameters and that the population measured plays an important role in prevalence estimates.

Preference of domestic horses for shade in a hot, sunny environment.

Provision of shade is recommended by best practice guidelines for horses living in hot, sunny environments despite a lack of research focused on potential benefits. We found in a previous study that horses without access to shade showed greater rectal temperature (RT), respiration rate (RR), and skin temperature (SK) and exhibited more sweat than horses that were completely shaded. Yet not known is whether horses will choose to stand in the shade when given a choice of areas with and without this resource. Our objective was to assess horse preference for shaded and unshaded areas in the hot and arid, sunny summer weather in Davis, California. For this preference test, 12 healthy, adult horses (6 mares, 6 geldings) were randomized into 3 sequential trials using 4 horses in each trial. The trials consisted of 2 d of acclimation and either 5 d (Trial 1) or 7 d (Trials 2 and 3) of observation. Horses were housed individually in dry lot pens. Half of each pen was covered by an open-sided shade structure. The amount of the pen shaded varied slightly throughout the day with a mean of 50.1% of the pen shaded. Physiological measurements (RT, RR, SK, sweat score) were recorded at 0900, 1230, and 1800 h. Behavioral observations (horses' location relative to shade, time spent walking, foraging, and standing) were recorded at 5-min intervals from 1300 to 1800 h daily and at 10-min intervals from 1800 to 1300 h on alternate days. Insect avoidance behavior was recorded for 1 min/h for each horse. Weather factors were recorded every 5 min, 24 h/d throughout the study; mean daytime ambient temperature was 29 °C ± 5 °C. Data were analyzed using PROC MIXED in SAS. Horses were located in the shade in 7.1% more observations than by chance (SE = 1.3, P < 0.001), with greatest use before and during peak solar radiation and then again following peak black globe temperature. Horses performed more walking and foraging behavior in the shaded areas (P < 0.01). Our research indicates that individually housed horses prefer shade when it is available in hot, sunny environments. These results support recommendations for access to shade when developing best practice guidelines for the care of domestic horses.

Physiological, behavioral, and serological responses of horses to shaded or unshaded pens in a hot, sunny environment.

Housing recommendations for horses invariably include providing access to shade on hot, sunny days, but the potential benefits have not been scientifically studied. This experiment measured physiological, behavioral, and serological responses of horses confined individually to completely shaded (SH) or completely unshaded (SUN) drylot pens during the summer in Davis, CA. Twelve healthy adult horses in a crossover design experienced both treatments for 5 d each. Rectal temperature, respiration rate, skin temperature, and sweat scores were recorded hourly from 1230 to 1730 h daily. Observations were recorded from 1200 to 1800 h for proximity to water, foraging, locomotion, and insect avoidance behaviors. Daily blood samples were obtained to measure cortisol, hematocrit, and neutrophil-to-lymphocyte ratio. Automated and handheld sensors were used to record environmental conditions. The mean ambient temperature from 1200 to 1800 h during the study was 30.6 °C. Rectal temperature was greater for horses in SUN than for SH (mean 37.8 °C and 37.5 °C, respectively, SE = 0.06, P = 0.002) as was respiration rate (25.5 and 20.5 breaths/min, SE = 1.3, P = 0.008), and skin temperature (35.6 °C and 34.6 °C, SE = 0.1, P < 0.001). Horses in SUN showed sweat in 51.4% of observations vs. 1.1% for horses in SH. Horses in SUN spent more time than SH horses standing near their water source (34.0% of observations vs. 20.2%, SE = 0.3, P = 0.004). No differences were observed for foraging, locomotion, or insect avoidance behavior (P > 0.05). Cortisol concentrations were greater in SUN than SH (3.4 and 2.6 µg/dL, respectively, P < 0.001) but remained within the normal range for resting horses. No treatment differences were observed for hematocrit or neutrophil-to-lymphocyte ratio (P > 0.05). Horses exhibited treatment differences in the physiological measures first, most notably in rectal temperature at 1230 h, corresponding to peak solar radiation. Behavioral responses followed these physiological changes, with treatment differences in time standing near water becoming apparent at 1400 h as ambient and black globe temperature increased. Our results indicate that both the SH and SUN treatment groups exhibited thermoregulatory responses to these summer conditions and horses benefited from shade, as it mitigated these physiological and behavioral changes. These results are applicable in developing best management practices for the care of domestic horses.

Behavioral and physiological effects of a short-term feed restriction in lactating dairy cattle with different body condition scores at calving.

Body condition score (BCS) around calving, and the typical BCS loss for up to 100 d after parturition, is associated with both production and reproductive performance of dairy cattle. In addition, there is public concern that thin cows may have impaired welfare, particularly in early lactation where feed demand exceeds pasture growth, and a lag exists between peak milk energy requirements and intake. The aim of this experiment was to determine how BCS at calving influences behavioral and physiological responses to a short-term feed restriction at 47 DIM. Body condition score (on a 10-point scale) at calving was manipulated by modifying the diets in the previous lactation of healthy dairy cattle to generate 3 treatment groups: low BCS (3.4; n=17), medium BCS (4.6; n=18), or high BCS (5.4; n=20). Cows were tested in 4 groups for 8 consecutive days; testing consisted of different levels of feed allocation (d 1 and 2: 100%; d 3 and 4: 75%; d 5: 50%; d 6 to 8: 125%), where 100% was 15kg of DM/cow per day. All BCS groups had similar and marked behavioral and physiological responses to feed restriction. For example, they increased vocalization, time spent eating silage and grazing, aggressive behavior, and fat metabolism (as measured by concentrations of ß-hydroxybutyrate and nonesterified fatty acids), and reduced milk production. Body condition affected some of these responses. Fewer cows with low BCS engaged in aggressive interactions in a feed competition test (trough filled with silage that could be consumed in 15 min) on the first day of feed restriction (low: 32%; medium: 74%; high: 64%; standard error of difference=15.4%). High BCS cows had greater concentrations of ß-hydroxybutyrate and nonesterified fatty acids throughout the experimental period, which suggests more fat mobilization; however, plasma leptin and fecal glucocorticosteroid metabolite concentrations were unaffected by BCS. Whereas cows demonstrated marked responses to feed restriction, the results suggest that a BCS of 3.4, 4.6, or 5.4 in healthy cows at calving does not overwhelmingly influence this response at 47 DIM.

Effects of adjustable and stationary fans with misters on core body temperature and lying behavior of lactating dairy cows in a semiarid climate.

Cows readily seek shade to reduce solar heat load during periods of high ambient temperature. Typically, auxiliary cooling systems are oriented to maximize cooling for shaded cows. However, when a shade structure is oriented north-south, stationary fan and mister cooling systems are unable to track shade as the sun's angle shifts throughout the day, and thus can become ineffective. The FlipFan Dairy Cooling System (Schaefer Ventilation Equipment, Sauk Rapids, MN) employs fans and misters that follow shade and compensate for wind speed by rotating on a horizontal axis. Multiparous, lactating Holstein cows (n=144) on a commercial dairy in Arizona were cooled by a fixed system comprised of stationary fans and misters acting as control or the adjustable FlipFan operated for 16.5 h/d (0830 to 0100 h). Core body temperatures (CBT) of 64 cows (4 pens/treatment; 8 cows/pen; 6d) and lying behavior of 144 cows (4 pens/treatment; 18 cows/pen; 5d) were collected by intravaginal and leg data loggers, respectively. Cows were balanced by milk production, blocked by days in milk, and randomly assigned to pen within block. Pen was the experimental unit. In a second experiment, isothermal maps were developed using a fixed system of thermal data loggers arranged in the shaded areas of the pens at different times of day and were analyzed for differences in the temperature-humidity index (THI) achieved by each cooling treatment. Ambient conditions consisted of a mean temperature of 33.0°C, mean relative humidity of 40.3%, and mean THI of 80.2. Mean 24-h CBT for FlipFan was lower than control (38.9 vs. 39.1±0.04°C). A treatment × time interaction was observed in which CBT of FlipFan was 0.4°C lower than control from 0600 to 0800h and 1500 to 1600h. Cows cooled by FlipFan spent more time lying down compared with those cooled by control (9.5 vs. 8.6 h/d). Cows under FlipFan had more frequent lying bouts than did those under control (12.8 vs. 10.7 bouts/d). Lower CBT and decreased standing time are consistent with the findings of other studies when ambient heat load was reduced. In the second experiment, the FlipFan system achieved a lower THI in the morning and evening (5.9 and 1.7%, respectively), and the THI also tended to be 0.8% lower in the afternoon compared with that of control. Results indicate that FlipFan is more effective than a stationary fan and mister system at decreasing CBT, increasing lying time and bouts, and providing a more desirable microenvironment for cows throughout the day in a semiarid environment.

Validation of an automated method to count steps while cows stand on a weighing platform and its application as a measure to detect lameness.

Weight shifting between legs and steps taken when cows stand may be a useful tool to assess cow comfort and lameness. Weight shifting is assessed by measuring the distribution of weight applied to each leg when standing on a weighing platform, whereas frequency of steps is traditionally measured with live observation or video recording. The objectives of this study were to validate an automated method to count steps from weight distribution measurements (experiment 1) and to assess the accuracy of the frequency of steps in detecting lameness (experiment 2). In experiment 1, 6 nonlame multiparous cows stood on a weighing platform covered with either concrete or rubber (1h/cow per surface) while stepping behavior was video recorded. Receiver operating characteristic curves were constructed, using the steps observed in the video recordings as the gold standard, to calculate the optimal threshold (based on the sum of sensitivity and specificity) of the weight applied to a leg to define a step. Optimal thresholds were similar between surfaces. The optimal thresholds, when pooling the 2 surfaces, were 127 and 98 kg for the front and rear pair for legs, respectively, with a specificity and sensitivity ≥0.96. Thresholds were used to construct an algorithm to count steps. In experiment 2, 57 cows (26 of them considered lame according to their gait score) stood for 15 min on the weighing platform. Frequency of steps taken with the front and rear pair of legs was calculated from the weight distribution measurements using the algorithm calculated in experiment 1. Lame cows took more steps per minute with the rear legs than did nonlame cows (1.6 vs. 1.0 steps/min; SE of the difference=0.2). As previously shown for weight shifting, the frequency of steps taken with the rear legs was a good predictor of lameness (area under the curve of the receiver operating characteristic curve=0.67; 95% confidence interval=0.52, 0.81). A positive relationship was observed between the frequency of steps and weight shifting (measured as SD of the weight applied over time to the legs) in both the front (R(2)=0.35) and rear (R(2)=0.49) legs, yet the slopes differed from 1 and the intercepts differed from 0, indicating that the 2 measures were related but not the same. In conclusion, weighing platforms can accurately calculate the frequency of steps automatically, and this measure shows promise as a tool to assess lameness.