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Background: Bovine respiratory disease (BRD) is a significant health problem in beef cattle production, resulting in considerable economic losses due to mortalities, cost of treatment, and reduced feed efficiency. The onset of BRD is multifactorial, with numerous stressors being implicated, including transportation from farms to feedlots. In relation to animal welfare, regulations or practices may require mandatory rest times during transportation. Despite this, there is limited information on how transportation and rest stops affect the respiratory microbiota. Results: This study evaluated the effect of cattle source (ranch-direct or auction market-derived) and rest stop duration (0 or 8 h of rest) on the upper respiratory tract microbiota and its relationship to stress response indicators (blood cortisol and haptoglobin) of recently weaned cattle transported for 36 h. The community structure of bacteria was altered by feedlot placement. When cattle were off- loaded for a rest, several key bacterial genera associated with BRD (Mannheimia, Histophilus, Pasteurella) were increased for most sampling times after feedlot placement for the ranch-direct cattle group, compared to animals given no rest stop. Similarly, more sampling time points had elevated levels of BRD-associated genera when auction market cattle were compared to ranch-direct. When evaluated across time and treatments several genera including Mannheimia, Moraxella, Streptococcus and Corynebacterium were positively correlated with blood cortisol concentrations. Conclusion: This is the first study to assess the effect of rest during transportation and cattle source on the respiratory microbiota in weaned beef calves. The results suggest that rest stops and auction market placement may be risk factors for BRD, based solely on increased abundance of BRD-associated genera in the upper respiratory tract. However, it was not possible to link these microbiota to disease outcome, due to low incidence of BRD in the study populations. Larger scale studies are needed to further define how transportation variables impact cattle health. [ABSTRACT FROM AUTHOR]

Increased trailer motion, coupled with large accelerations and decelerations, has been associated with decreased carcass quality and increased stress indicators in cattle, sheep, and hogs. However, motion of livestock trailers has not been measured in North-American cattle semi-trailers over long distances (> 1000 km). The objectives of this study were to develop a practical method of measuring transport trailer accelerations, to describe the range of accelerations cattle are exposed to under North American conditions, and to conduct a preliminary analysis of trailer accelerations for each compartment and its effect on carcass bruising. The root mean square (RMS) of acceleration was measured at a sampling rate of 200 Hz in 3 orthogonal axes; x (vertical), y (front-to-rear), and z (lateral; side-to-side) by clamping an accelerometer to the cross beam below each of the five compartments of 8 trailers transporting a total of 330 animals (674 ± 33.3 kg BW) from an assembly yard to a processing facility. Journeys took place on separate days and ranged in duration from 13 to 15.7 h. The number and severity of bruises per carcass were determined prior to trimming for n = 290 carcasses and the number of bruises per carcass ranged between 0.38 and 12.75, whereas the bruising score per carcass ranged between 0.38 and 14.88. Mean number of bruises and severity of bruises (bruising scores were assigned according to size using a three-point scale: 1) ≤ 6.5 cm, 2) 6.5 to 12 cm, and 3) ≥ 12 cm and bruising severity was determined by applying the weighted score to each bruise according to bruise area) per carcass was 4.52 ± 2.43 (n) and 5.31 ± 2.84, respectively. Accelerations in commercial transport vehicles were found to range between 0.33 and 1.90 m/s2, whereas the mean RMS of acceleration for all trailers (n = 31 accelerometers) was 1.01 ± 0.32 m/s2, 0.72 ± 0.31 m/s2, and 0.97 ± 0.30 m/s2 for the x, y, and z axes, respectively. Horizontal acceleration was greatest in the nose, back, and doghouse compartments (P = 0.05), whereas lateral acceleration was greatest in the nose and back compartments (P = 0.08). Although the nose, back, and doghouse compartments had the highest RMS values for the lateral and horizontal axes, there were no significant relationships between bruising and acceleration. Replication of this research is required to further understand the relationships between trailer motion, carcass bruising, and overall animal welfare in cattle transported long distances. [ABSTRACT FROM AUTHOR]

Ovariectomy (spaying) using the trans-vaginal dropped ovary technique (DOT) is performed to prevent pregnancy in cull female beef cattle that are not retained for breeding stock in areas practicing extensive grazing management. There are no reports describing analgesia for this surgical procedure. The objective of this study was to measure behavioral and physiological responses to determine whether an analgesic protocol of BXK [butorphanol (0.01 mg/kg), xylazine (0.02 mg/kg), and ketamine (0.04 mg/kg)] injected intramuscularly (i.m.) before spaying could mitigate procedural and immediate postsurgical pain, and whether oral meloxicam (1 mg/kg) administered at the time of spaying could mitigate postsurgical inflammatory pain. Forty-four red Angus and Angus crossbred yearling heifers (322 ± 27.0 kg BW) were randomly allocated to 1 of 3 groups: PALP (control; palpated but not spayed; n = 14), SPAY (spayed with no analgesia; n = 15), and BXKM (spayed with analgesia; n = 15). Behavioral measurements included visual analog scale (VAS) score, flight speed (FS), stride length (SL), and gait score (GS), as well as activity (lying, standing) and feeding behavior. Physiological measurements included salivary cortisol (SC), haptoglobin (Hp), serum amyloid A (SAA), substance P (SP), complete blood count (CBC), and rectal temperature (RT). Saliva and blood samples were collected, and RT, FS, SL, and GS were measured on day −1, day 0 (time of palpation/spaying), and hours 1, 2, 4, and days 1, 2, 4, and 7 after palpation/spaying. The BXKM heifers had lower SC concentrations than SPAY heifers at 1 h (P = 0.01) and 2 h (P = 0.004). Heifers treated with BXKM had Hp concentrations lower than SPAY heifers at 2 d (P = 0.01), 4 d (P < 0.001), and 7 d (P = 0.008), and lower Hp concentrations than PALP heifers at 4 d (P < 0.001). Concentrations of SAA were greater (P = 0.04) in BXKM heifers than in PALP heifers at 1 h and lower in PALP heifers than in BXKM heifers (P = 0.02) and SPAY heifers (P = 0.05) at 1 d. Heifers in the BXKM group had higher RT than PALP and SPAY heifers at 1 h (P < 0.001) and 2 h (P = 0.004). Results suggest that DOT ovariectomy is acutely stressful and painful and administration of BXK before spaying and meloxicam at the time of spaying mitigated the procedural and postsurgical stress, pain, and inflammation. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of the extended-term delivery of anesthesia on the physiological and behavioral signs of pain caused by band castration in 1-month-old bull calves. Forty-eight calves (37.04 ± 8.98 days of age) were homogenously assigned by age to one of three band castration protocols (n = 16/protocol); 1) regular elastrator bands (REG), 2) regular elastrator bands preceded by two 2-mL injections of lidocaine (REG+L; LIDO-2 with epinephrine, Rafter 8 Products Inc, Calgary, Canada), and 3) lidocaine elastrator bands (LBAND; Care-Ring, Chinook Contract Research Inc., Calgary, Canada). During the castration procedure, two observers scored (from 1 to 10) how much pain each animal was experiencing (visual analog score, VAS), number of body shakes and leg kicks for each calf. Calves were weighed on d -1, 0, 14, 28, 42, and 56. Hair cortisol concentration was measured on d -1, 28, and 56. Saliva cortisol concentration was measured right after castration, 60, 120, 240 minutes after castration, on d 1 and weekly thereafter until d 56. Flight speed (FS) was recorded on d -1, right after castration, 60, 120, 240 minutes after castration, d 1, and weekly thereafter until d 56. Calf behaviors in the pen indicative of pain and discomfort were recorded on d 0, 1, and weekly thereafter until d 56. The REG+L calves tended to have decreased (P = 0.09) VAS scores than REG calves. The average daily gain was greater (P < 0.01) from d 42 to 56 than from d 1 to 42, and from d 1 to 28 compared with d 28 to 42 in all treatment groups. The REG calves had decreased (P < 0.01) hair cortisol concentrations than both REG+L and LBAND calves. Saliva cortisol concentrations were greater (P < 0.01) 60 minutes after castration than any other sample time in all treatment groups. There was an interaction between treatment and time (P = 0.04), where only LBAND had a greater FS immediately after castration compared with d -1. When calves were observed in the pen there were no treatment effects (P > 0.10) but only time differences (P < 0.05) in the frequency of head turns, oral behaviors, tail flicks, and number of standing and walking bouts. The behavioral and physiological parameters assessed showed expected results on the effects of band castrating calves, while the administration of lidocaine via REG+L or LBAND did not show any pain mitigation effect compared with the standard industry banding method (REG). [ABSTRACT FROM AUTHOR]

This study evaluated the effect of feeding pelleted or mash ergot contaminated grain fed continuously or intermittently on the growth performance, blood serum variables, and carcass quality of finishing beef steers. Sixty black angus steers (442 ± 36.7 kg) were used in a complete randomized finishing (90% concentrate:10% barley silage DM basis) 126-d study. Steers were randomly assigned to 4 different treatments and individually housed. Treatments included: 1) control ration [CON; no added ergot alkaloids (EA)], 2) continuous ergot mash (CEM; fed continuously at 2 ppm total EA), 3) intermittent ergot mash (IEM; fed at 2 ppm EA during the first week of each 21-d period and control diet for the remaining 2 weeks), and 4) intermittent ergot pellet (IEP; fed at 2 ppm EA incorporated into a pelleted supplement during the first week of each 21-d period and control diet for the other 2 weeks). Steers were weighed every 21 d and blood samples were collected on day 0, 42, 84, and 126. Steer DMI (P < 0.01, 9.95 vs. 11.05 kg/day) and ADG (P = 0.04) decreased for all EA treatments compared with the CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2 kg), final BW (P = 0.03, 617.9 vs. 662.2 kg), and carcass weight (P = 0.06) decreased for all EA steers compared with the CON steers. No treatment effects (P > 0.05) were observed for carcass dressing percentage, ribeye area, marbling score, or liver abscess. The percent of carcasses graded AAA decreased for all EA steers compared CON steers (P < 0.01, 46.7 vs. 93.3%). Steers fed EA had increased rectal temperature compared with CON steers (P < 0.01, 39.8 vs. 39.4 °C). Hair cortisol concentrations were less in steers fed IEP (P = 0.05, 1.23 vs. 1.76 pg/mg) than CON. No treatment effects (P > 0.05) were observed for complete blood count, and serum prolactin, haptoglobin, albumin, alkaline phosphatase, alanine transaminase, amylase, calcium, creatine, glucose, lipase, total bilirubin, total protein, or globulin. Blood urea nitrogen was less for EA steers compared with CON (P = 0.01, 3.48 vs. 4.10 mmol/L). The IEM steers had decreased concentrations of serum gamma-glutamyl transferase compared with IEP steers (P = 0.04, 23.4 vs. 28.5 IU). Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters. Results suggest that continuously or intermittently feeding an ergot contaminated diet (2 ppm EA) can significantly reduce intake, growth performance, and carcass weight, with minimal impact on blood serum variables in finishing steers. Pelleting was not an effective method of reducing ergot toxicity. [ABSTRACT FROM AUTHOR]

Lameness is a significant health issue in feedlot cattle, having major economic, labor, and welfare implications. Digital dermatitis (DD), a lesion of the plantar surface of the foot, and foot rot (FR), which affects the interdigital cleft, are common infectious causes of feedlot lameness with bacterial origins. These hoof lesions can occur alone or in combination in the same hoof (DD+FR). Over a one-year period (2019-2020), 208 hoof swabs were obtained from cattle with FR (n = 55), DD (n = 18), and DD+FR (n = 29), and 5 completely healthy cattle (controls) from three southern Alberta commercial feedlots. 16S rRNA gene sequencing was used to characterize the bacterial microbiota of DD, FR, and DD+FR lesions relative to corresponding healthy skin controls found within the same affected animals. DD and FR lesion microbiotas showed reduced diversity compared with corresponding control skin. Multiple Treponema (members of Spirochaetaceae Family) species were differentially abundant in DD lesions compared with contralateral control skin. FR lesions are characterized by an abundance of Fusobacterium necrophorum and Porphyromonas levii, compared with contralateral control skin. The microbiome of DD+FR lesions was similar to FR lesions, where F. necrophorum and P. levii were increased compared with contralateral control skin. Other differentially abundant taxa (Helcococcus, Succiniclasticum spp.) found in FR and DD+FR lesions had been previously associated with DD, suggesting there may be an overlap of bacteria that have a role in both types of hoof lesions. The findings support previous literature showing that FR and DD are polybacterial in nature. The identification of novel bacterial species of DD and FR lesions could contribute information for the development of more targeted and effective prevention and treatment strategies. A novel finding of the sequencing analysis for hooves with concurrent DD and FR infection was characterized. [ABSTRACT FROM AUTHOR]

We explored whether straw bedding at rest stations might affect latency and duration of lying down beyond the 8h rest required at rest stops during long distance transport. Animals arriving to commercially operated rest stops (n=75, 6/load, opportunistically selected) were rested in pens (15.5 × 9.5 m) that were either bedded (n=38, straw, 14 cm deep) or non-bedded (n=37). The lying activity of each animal was recorded every 10 min for 8 h. The independent variables recorded included: bedding treatment, mean animal weight/load (kg), and space allowance [k-value = (m²/animal) / (BW2/3)] in the trailer. Ordinary linear and mixed linear regression models were fitted to assess lying latency and duration, respectively. Bedding affected latency to lie down, but its effect depended on space allowance in the truck: among cattle transported with low space allowance (2.08 - 3.29 m²/300 kg animal), bedded cattle laid down sooner than non-bedded cattle (P< 0.001). Comparing only cattle in bedded pens, cattle laid down sooner when transported with low space allowance (2.08 - 3.29 m²/300 kg animal) compared with medium space allowance (>3.29 - 3.69 m²/300 kg animal; P=0.003). Bedding also affected lying duration, but the effect depended on mean animal weight; as mean animal weight of the load increased so did duration but the effect was greater among bedded animals (P=0.027). In summary, cattle transported at high stocking densities are most likely to benefit from bedding as are heavier animals. [ABSTRACT FROM AUTHOR]