Evaluation of the capacity and effective angle of thalamic damage for 2 commercially available captive bolt tool types on cadaver heads from sows >200 kg body weight.

This study evaluated the ability of 2 penetrating captive bolt (PCB) types (PISTOL, INLINE) to reach and disrupt the thalamus when applied in 2 placements (FRONTAL, BEHIND EAR) to chilled cadaver heads (N = 60) from sows >200 kg. Heads were randomly distributed across 6 treatments (n = 10): FRONTAL-INLINE, FRONTAL-PISTOL, FRONTAL-NO SHOT, BEHIND EAR-INLINE, BEHIND EAR-PISTOL, and BEHIND EAR-NO SHOT. The FRONTAL shot was placed 3.5 cm superior to the optic orbits at the midline; the BEHIND EAR shot was placed directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For INLINE treatments, a Jarvis PAS-Type C 0.25R Super Heavy Duty PCB with a Long Bolt and 6.0 GR power loads was used. For PISTOL treatments, a Jarvis PAS-Type P 0.25R Pistol PCB with a Long Stunning Rod Nosepiece Assembly and 3.5 GR power loads was used. Heads were split along the bolt with a band saw. Tissue depth measurements are reported as Mean ±â€…SE followed by 97.5% one-sided upper reference limit (URL). Total tissue thickness was less (P < 0.0001) at the FRONTAL (56.31 ±â€…1.76 mm; URL: 73.17 mm) than the BEHIND EAR placement (95.52 ±â€…3.30 mm; URL: 126.53 mm). Thalamic depth was less (P < 0.0001) at the FRONTAL (78.31 ±â€…1.32 mm; URL: 88.19 mm) than the BEHIND EAR placement (111.86 ±â€…3.22 mm; URL: 135.99 mm). The effective angle was greater (P < 0.0001) at the FRONTAL (4.72 ±â€…0.20°) than the BEHIND EAR placement (3.22 ±â€…0.17°). Potential for bolt-brain contact was not different (P = 1.0000) between FRONTAL-INLINE (10/10, 100% ±â€…0.01%), FRONTAL-PISTOL (10/10, 100% ±â€…0.01%), BEHIND EAR-INLINE (9/10, 90% ±â€…9.49%), and BEHIND EAR-PISTOL (10/10, 100% ±â€…0.01%); brain damage (P = 0.5577) between FRONTAL-INLINE (9/9, 100% ±â€…0.02%), FRONTAL-PISTOL (10/10, 100% ±â€…0.02%), BEHIND EAR-INLINE (4/10, 40% ±â€…15.49%), and BEHIND EAR-PISTOL (1/10, 10% ±â€…9.49%); potential for bolt-thalamus contact (P = 0.0683) for FRONTAL-INLINE (2/10, 20% ±â€…12.65%), FRONTAL-PISTOL (8/10, 80% ±â€…12.65%), BEHIND EAR-INLINE (7/9, 77.78% ±â€…13.86%), and BEHIND EAR-PISTOL (9/9, 100% ±â€…0.02%); or thalamic damage (P = 0.8041) for FRONTAL-INLINE (1/10, 10% ±â€…9.49%), FRONTAL-PISTOL (1/10, 10% ±â€…9.49%), BEHIND EAR-INLINE (2/8, 25% ±â€…15.31%), and BEHIND EAR-PISTOL (0/9, 0% ±â€…0.00%). The FRONTAL placement with an INLINE PCB may present the least risk of failure for the PCB euthanasia of mature sows >200 kg body weight due to less total tissue thickness and thalamic depth, greater effective angle, and prevalent brain damage.

Euthanasia is a necessary procedure to safeguard animal welfare on swine farms. Penetrating captive bolt (PCB) is often used to euthanize sows by passing a metal bolt through the animal's skull and into the brain. This causes severe brain damage with the anticipated result of an immediate loss of consciousness. This study evaluated frontal and behind-ear PCB placements for sows weighing more than 200 kg with 2 commercially available types of PCB devices. The frontal placement, when used with an inline free-flight PCB device, may be more reliable than other placement and device combinations due to less total tissue thickness, more room for error with positioning the PCB, and prevalent brain damage.

Quantification of cooling effects on basic tissue measurements and exposed cross-sectional brain area of cadaver heads from Holstein cows > 30 mo of age.

Penetrating captive bolt (PCB) is the primary method of preslaughter stunning for cattle and is also used for on-farm euthanasia. The objective of this study was to quantify the impact of cooling on the soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area of cadaver heads collected from mature (> 30 mo of age) dairy cows following the application of a PCB stun in a frontal placement. Hide-on cadaver heads were obtained from culled dairy cows (N = 37) stunned in a frontal location using a handheld PCB device (Jarvis Model PAS-Type C 0.25R Caliber Captive Bolt, Long Bolt) at a commercial slaughter establishment. Following transport to the University of Wisconsin-River Falls, heads were split at midline along the bolt path by a bandsaw and then underwent FRESH, CHILL24, CHILL48, and CHILL72 refrigeration treatments. The FRESH treatment involved images collected immediately after splitting each head, the CHILL24 treatment involved images collected after 24 h of refrigeration, the CHIL48 treatment involved images collected after 48 h of refrigeration, and the CHILL72 treatment involved images collected after 72 h of refrigeration. Measurements of soft tissue thickness, cranial thickness, total tissue thickness, and cross-sectional brain area were recorded for each refrigeration treatment. Soft tissue thickness did not differ caudal to (P = 0.3751) or rostral to (P = 0.2555) the bolt path. Cranial thickness did not differ caudal to (P = 0.9281) or rostral to (P = 0.9051) the bolt path. Total tissue thickness did not differ caudal to (P = 0.9225; FRESH: 24.77 mm, CHILL24: 23.93 mm, CHILL48: 24.27 mm, CHILL72: 42.30, SE: 0.86) or rostral to (P = 0.8931; FRESH: 24.09 mm, CHILL24: 23.99, CHILL48: 24.26, CHILL72: 24.43 mm, SE: 0.79 mm) the bolt path. Cross-sectional brain area was not different (P = 0.0971) between refrigeration treatments (FRESH: 9,829.65 ±â€…163.87 mm2, CHILL24: 10,012.00 ±â€…163.87 mm2, CHILL48: 9,672.43 ±â€…163.87 mm2, CHILL72: 10,235.00 ±â€…166.34 mm2). This study demonstrated that FRESH tissue parameters can be determined from cattle cadaver heads refrigerated for 24, 48, or 72 h.

Relationship of tissue dimensions and three captive bolt application sites on cadaver heads from mature swine (Sus scrofa domesticus) <200 kg body weight.

Penetrating captive bolt (PCB) is a common method of euthanasia for swine but has not been evaluated for mature swine < 200 kg body weight (BW). The objectives were to determine tissue depth, brain contact plane, and visible brain tissue damage (brain damage[BD]) for the common FRONTAL (F) and alternative TEMPORAL (T) and BEHIND EAR (BE) placements for PCB use on sows and boars weighing < 200 kg. Cadaver heads were obtained from 30 sows and 30 boars (estimated BW, mean ±â€…SD; sows: 165.8 ±â€…22.4 kg; boars: 173.6 ±â€…21.4 kg) from a slaughter establishment after electrical stunning and exsanguination. Heads were cooled at 2 to 4 °C for approximately 64 h. A Jarvis PAS-Type P 0.25R PCB with a Long Stunning Rod Nosepiece Assembly and a 3.5 GR power load was used for all PCB applications at the following placements: F-3.5 cm superior to the optic orbits at midline, T-at the depression posterior to the lateral canthus of the eye within the plane between the lateral canthus and the base of the ear, or BE-directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For sows, the bolt path was in the brain for 10/10 (100.0%, 95% CI: 69.2% to 100.0%) F, T, and BE heads. In heads that could reliably be assessed for BD, BD was detected in 10/10 (100.0%, 95% CI: 69.2% to 100.0%) F heads, 9/9 (100.0%, 95% CI: 66.4% to 100.0%) T heads, and 0/10 (0.0%, 95% CI: 0.0% to 30.1%) BE heads. For boars, the bolt path was in the plane of the brain for 8/9 (88.9%, 95% CI: 51.8% to 99.7%) F heads, 9/10 (90.0%, 95% CI: 55.5% to 99.7%) T heads, and 11/11 (100.0%, 95% CI: 71.5% to 100.0%) BE heads. In heads that could reliably be assessed for BD, BD was detected in 8/9 (88.9%, 95% CI: 51.7% to 99.7%) F heads, 7/10 (70.0%, 95% CI: 34.8% to 93.3%) T heads, and 4/11 (36.4%, 95% CI: 10.9% to 69.2%) BE heads. Tissue depth was reported as mean ±â€…SE followed by 95% one-sided upper reference limit (URL). For sows, total tissue thickness differed (P < 0.05) between placements (F: 49.41 ±â€…2.74 mm, URL: 70.0 mm; T: 62.83 ±â€…1.83 mm, URL: 76.6 mm; BE: 84.63 ±â€…3.67 mm; URL: 112.3 mm). Total tissue thickness differed (P < 0.05) between placements for boars (F: 54.73 ±â€…3.23 mm, URL: 77.6 mm; T: 70.72 ±â€…3.60 mm, URL: 96.3 mm; BE: 92.81 ±â€…5.50 mm; URL: 135.3 mm). For swine between 120 and 200 kg BW, the F placement may have the greatest likelihood for successful euthanasia due to the least total tissue thickness and may present less risk for failure than the T and BE placements.

Euthanasia is an important procedure to protect animal welfare and cannot be avoided on swine farms. A common method of euthanasia for swine is penetrating captive bolt (PCB), which involves passing a metal bolt through the skull into the brain. This process should result in an immediate loss of consciousness. The use of PCB has been evaluated for market hogs and heavier sows and boars, but not for sows and boars weighing < 200 kg. As pigs mature, the cranial thickness at the common frontal PCB placement increases due to the expansion of sinus cavities. This makes PCB euthanasia more challenging for sows and boars. As a result, alternative PCB application sites, including behind the ear and at a temporal location, have been proposed. This study evaluated frontal, temporal, and behind-ear placements for PCB application to cadaver heads from sows and boars weighing < 200 kg. The frontal placement appeared to be more reliable than the temporal or behind ear placements due to the least tissue for the bolt to travel through to reach the brain, the greatest potential target area, and prevalent brain damage.

History and best practices of captive bolt euthanasia for swine.

The definition of animal welfare includes how an animal dies. As such, euthanasia is intrinsically linked to animal welfare, and ensuring a good death through effective, safe, and validated practices is a critical piece of promoting positive animal welfare. The objective of this review is to provide a better understanding of the literature on the euthanasia of swine via penetrating captive bolt (PCB) and nonpenetrating captive bolt (NPCB), as well as a history of captive bolt use, and indicators of sensibility and insensibility. To do this, we performed a systematic review that included 30 peer-reviewed articles and 17 other publications. NPCB devices have been validated as an effective single-step euthanasia method for neonatal and preweaning swine, as well as a two-step euthanasia method for nursery swine. PCB devices have been validated as an effective euthanasia method for nursery and market swine up to 120 kg, but further investigation is required for the use of captive bolt devices on mature breeding sows and boars.

Relationship of tissue dimensions and three captive bolt placements on cadaver heads from mature swine (Sus scrofa domesticus) > 200 kg body weight.

Three penetrating captive bolt (PCB) placements were tested on cadaver heads from swine with estimated body weight (BW) >200 kg (sows = 232.9 ± 4.1 kg; boars = 229.3 ± 2.6 kg). The objectives were to determine tissue depth, cross-sectional brain area, visible brain damage (BD), regions of BD, and bolt-brain contact; and determine relationships between external head dimensions and tissue depth at each placement. A Jarvis PAS-Type P 0.25R PCB with a Long Stunning Rod Nosepiece Assembly and 3.5 g power loads was used at the following placements on heads from 111 sows and 46 boars after storage at 2 to 4 °C for ~62 h before treatment: FRONTAL (F)-3.5 cm superior to the optic orbits at midline, TEMPORAL (T)-at the depression posterior to the lateral canthus of the eye within the plane between the lateral canthus and the base of the ear, or BEHIND EAR (BE)-directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For sows, the bolt path was in the plane of the brain for 42/42 (100%, 95% confidence interval [CI]: 91.6% to 100.0%) F heads, 39/40 (97.5%, 95% CI: 86.8% to 99.9%) T heads, and 34/39 (87.5%, 95% CI: 72.6% to 95.7%) BE heads; for the heads that could reliably be assessed for BD damage was detected in 25/26 (96.2%, 95% CI: 80.4% to 99.9%) F heads, 24/35 (68.6%, 95% CI: 50.7% to 83.2%) T heads, and 5/40 (12.5%, 95% CI: 4.2% to 26.8%) BE heads. For boars, the bolt path was in the plane of the brain for 17/17 (100.0%, 95% CI: 80.5% to 100.0%) F heads, 18/18 (100.0%, 95% CI: 81.5% to 100.0%) T heads, and 14/14 (100.0%, 95% CI: 76.8% to 100.0%) BE heads; damage was detected in 11/12 (91.7%, 95% CI: 61.5% to 99.8%) F heads, 2/15 (13.3%, 95% CI: 1.7% to 40.5%) T heads, and 7/14 (50.0%, 95% CI: 23.0% to 77.0%) BE heads. Tissue depth was reported as mean ± standard error followed by 95% one-sided upper reference limit (URL). For sows, total tissue thickness was different (P < 0.05) between placements (F: 52.7 ± 1.0 mm, URL: 64.1 mm; T: 69.8 ± 1.4 mm, URL: 83.9 mm; BE: 89.3 ± 1.5 mm, URL: 103.4 mm). In boars, total tissue thickness was different (P < 0.05) between placements (F: 41.2 ± 2.1 mm, URL: 56.3 mm; T: 73.2 ± 1.5 mm, URL: 83.4 mm; BE: 90.9 ± 3.5 mm, URL: 113.5 mm). For swine > 200 kg BW, F placement may be more effective than T or BE due to less soft tissue thickness, which may reduce concussive force. The brain was within the plane of bolt travel for 100% of F heads with BD for 96.2% and 91.7% of F sow and boar heads, respectively.

Phylogenetically Distinct Near-Complete Genome Sequences of Porcine Reproductive and Respiratory Syndrome Virus Type 2 Variants from Four Distinct Disease Outbreaks at U.S. Swine Farms over the Past 6 Years.

Porcine reproductive and respiratory syndrome virus (PRRSV) continues to mutate, causing disruptive PRRS outbreaks in farms that lead to reproductive failure and respiratory disease-associated mortality. We present four new PRRSV type 2 variants in the United States belonging to four distinct orf5 sublineages within lineage 1.

Veterinary Student Knowledge and Attitudes about Swine Change after Lectures and a Farm Visit.

Veterinary schools are facing the challenge of increasing animal welfare (AW) training while also attracting future practitioners to livestock medicine. Both objectives may be better achieved through farm visits early in veterinary training. First year veterinary students at the University of Minnesota (n = 103) were surveyed during the Spring 2019 Professional Development II course to document their knowledge, attitudes, and values relative to pigs, AW, and the industry before and after classroom and online lectures and a visit to a farrow-to-wean farm. Quantitative (Kruskal-Wallis, Kendall tau-c and Chi-Square) and qualitative (content analysis) analyses were used to identify shifts in knowledge and attitudes and associations with demographics and use of the AW values of biological functioning, affective state, and natural living. Most students were female (85.4%), from urban/suburban backgrounds (68.9%), and did not wish to work with livestock (66.0%). Knowledge scores (p <.05) and attitudes toward pigs (p = .0152) improved after visiting the farm. Satisfaction with AW on most commercial farms shifted after the farm visit (p = .0003), with those valuing biological functioning becoming more satisfied (p = .0342). In contrast, students who visited the farm when enrichment was provided were more dissatisfied compared to those who toured the farm without enrichment (p = .0490). Those referencing natural living (p = .0047) rated the toured farm as a poorer steward of welfare. Students' AW concerns included behavioral restriction in individual stalls and injury and lameness in group pens. Farm visits are an important tool in veterinary education, but may result in segmentation in student knowledge and attitudes relative to livestock welfare.