The use of electrical stunning followed by electro-immobilization for the humane slaughter of cattle

Sir;- In New Zealand, calves are often electrically stunned before slaughter. However, electrical stunning is not usually used for adult cattle, primarily because the large size of the adult animal makes restraint more difficult, resulting in less reproducible stunning, with potential danger to personnel from animal movement. In addition, the slaughter of cattle may be inhumane if the stunning process does not ensure immediate and permanent insensibility (Newhook and Blackmore 1982b). The use and humaneness of electrical stunning of sheep and cattle have been the subject of our recent research, in which we have addressed and resolved many of these problems. We wish to relate our observations in the context of head-only electrical stunning of cattle followed by electro-immobilization to maintain insensibility and ensure carcass stillness.     

Tuberculosis in a New Zealand (Hooker's) sea lion

Extract

Tuberculosis has been described in seven species of pinnipeds. Based on host preference, phenotype and genetic and antigenic testing, the causal bacterium has been classified as a distinct species, Mycobacterium pinnipedii, within the M. tuberculosis complex. An adult male New Zealand sea lion (Phocarctos hookeri) was found dead on the Otago coastline in mid 2005. Gross necropsy revealed multiple caseous foci throughout the lungs, subcutaneous and thoracic lymph nodes, and mesenteric lymph nodes. Histopathological examination showed granulomatous lesions containing numerous intra-lesional acid fast organisms. The organism was confirmed as being a member of the M. tuberculosis complex, based on restriction enzyme analysis. Spoligotyping is pending. This is the first confirmed case of mycobacterial disease in a New Zealand sea lion.     

The effect of four anesthetic protocols on the spleen in dogs

Splenic enlargement following administration of barbiturates has been well described in dogs; other agents have not been investigated. This study aimed to compare the effects of four anesthetic protocols on splenic size.
Twenty-four fasted Beagle dogs scheduled for laparotomy were allocated to one of the four groups. Group 1: acepromazine and butorphanol followed by induction with thiopental; Group 2: acepromazine and butorphanol followed by induction with propofol; Group 3: medetomidine and butorphanol followed by induction with propofol; Group 4: medetomidine and butorphanol followed by induction with ketamine and diazepam. Anesthesia was maintained with halothane in oxygen, intravenous fluids were administered. Splenic length, width and height were measured once when the abdomen was opened and again just prior to closure. Spleens were also traced, the image was digitized, and the area was calculated. PCV and total solids were measured before and after pre-medication, after induction, and each time the spleen was measured. Data were analyzed using a Repeated Measures anova with splenic variables indexed by body surface area and dose of induction agent as a covariate.
Area and width of the spleens were less in the dogs of Groups 2 and 3 than in those of the other groups. Splenic area and length did not change significantly during surgery. Dosage of propofol was not significantly different between Groups 2 and 3. Baseline PCV was not significantly different among groups and decreased significantly in all dogs, but at different times. In Groups 1 and 2, the decrease occurred after pre-medication, in Group 3 at induction, and in Group 4 during surgery. A significant decrease in TS occurred in all groups during surgery.
We concluded that the use of propofol resulted in smaller spleen size during surgery than that following the use of thiopental. Multiple factors influenced the PCV.     

Bacteroides ruminicola as a possible cause of “lumpy-jaw” in Bennett's wallabies

Bacteroides ruminicola subspecies brevis was isolated from the jaw lesions of three Bennett's wallabies with “lumpy-jaw”. Nocardia was not isolated from any of the three animals. It is suggested that Bacteroides ruminicola subspecies brevis is the causal organism of “lumpy-jaw” and was one of the organisms noted in this condition by Fox in 1923. As far as we are aware this subspecies has not previously been reported as a pathogen in animals or human beings. The results of antibiotic sensitivity tests are given and therapy with metronidazole or clindamycin is suggested.     

Evaluation of intraperitoneal and subcutaneous lidocaine and bupivacaine for analgesia following ovariohysterectomy in the dog

The role of ketamine (K) in pain management is controversial. It is reported to provide visceral analgesia in cats. This study aimed to assess its somatic actions using a thermal threshold (TT) model. Six cats (four spayed females, two castrated males, 4.3–7.2 kg) participated in the study. The day before each study, the thorax of each of the cats was shaved and a cephalic catheter was placed. TT was measured using a device specifically developed for cats. A heater element and temperature sensor housed in a small probe were held against the thorax of the cats with an elastic band and pressure bladder to assure consistent contact. The skin temperature was recorded before each test, then the heater was activated. When the cat responded by flinching, turning, or jumping, the stimulus was terminated and the threshold temperature was recorded. Treatments were 2 mg kg^?1 of K (10 mg mL^?1), or 0.2 mL kg^?1 of saline (S) IV, given in a randomized cross‐over design with at least 1 week between treatments. The investigator was blinded to the treatment. TT was measured thrice before treatment (baseline threshold) at 15 minutes, then every 30 minutes for 8 hours and once at 24 hours after injection. Data were analyzed using a four‐factor anova . Cats were sedated for 45 minutes following K treatment. There was no difference in baseline TT between treatments (K = 41.9 ± 1.7 °C, S = 41.0 ± 1.45 °C), and no change in TT at any time in the S group. TT increased significantly at 15 and 30 minutes after K, then decreased below baseline values between 210 and 390 minutes, with a nadir of 38.8 ± ± 1.05 °C at 390 minutes. During this time period, cats exhibited normal activity, but responses to thermal stimuli were exaggerated. This study suggested that K caused a delayed onset hyperalgesia in cats.     

Electrical stunning of red deer (Cervus elaphus)

Eighteen of 23 red deer (Cervus elaphus) at a deer slaughtering premises were successfully stunned with an apparatus modified from that normally used to stun sheep. The five unsuccessful electrical stuns were associated with poor head restraint and poor head contact by the electrodes. The median stunning current was 0.9 A, and in the majority of cases the duration of stunning was less than 1 second. The signs of the electrically induced epileptiform seizures in the deer were dissimilar to those seen in sheep, cattle and pigs, in that the initial tonic phase was less marked, and of shorter duration. A similar shorter and less obvious tonic phase was noted in four deer shot with a captive bolt pistol. Two animals which were electrically stunned, and bled within 10 seconds, showed no signs of recovery while bleeding. The electroencephalograms of four deer stunned with currents of 1.3 A for a duration of either 0.5 or 1.0 seconds were recorded under more controlled conditions. All four animals developed electroencephalograms typical of an epileptiform seizure. The animals exhibited behavioural reactions similar to the other 18 animals in the trial at the deer slaughtering premises and were rendered unconscious for between 54 and 122 seconds. The electroencephalogram activity amplitude was greater than that recorded immediately before stunning and took between 6 and 9 seconds to build up to maximum value. It is concluded that, providing the heads of deer are adequately restrained, head-only electrical stunning can be incorporated into a humane method of slaughter for deer.     

The role of the vertebral arteries in maintaining spontaneous electrocortical activity after electrical stunning and slaughter in calves

This paper examines the role of the vertebral arteries of calves in determining the time to loss of spontaneous electrocortical activity after slaughter by a throat-cut severing the soft tissues of the neck ventral to the spinal column. Four calves with the vertebral arteries ligated took 43 +/- 1.3 s to lose cortical activity after the throat was cut. Four similar animals with intact vertebral arteries and the rostral end of the common carotid arteries clamped immediately after slaughter, to ensure that vertebral blood passed to the brain, took 51 +/-25 s to lose cortical activity. It was concluded that factors other than blood flow from the vertebral arteries contribute to the prolonged time to loss of electrocortical activity after slaughter that has been observed in some calves.     

A scanning electron microscope study of glyphosate deposits in relation to foliar uptake

The effects of several formulations on foliar uptake of glyphosate, and on the morphology of glyphosate deposits on leaves, were examined in Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.). [¹⁴C]glyphosate, in the form of the free acid or the isopropylamine salt (IPAS), was applied to foliage alone or with various adjuvants. Uptake of all glyphosate IPAS formulations was greater than that of the corresponding acid formulation. Addition of ‘Tween 20’ enhanced the uptake of glyphosate IPAS compared to glyphosate alone, but had no effect on the uptake of glyphosate acid. Ammonium sulfate and the ‘Roundup’ formulation blank increased the uptake of glyphosate acid and IPAS to 2-3 times that of herbicide alone. Surface deposits, as observed by scanning electron microscopy, varied with the formulation of the herbicide, although there were no differences between the acid and IPAS formulations. Glyphosate alone initially formed a deposit with both crystalline and smooth, amorphous areas. Later in the treatment period (48 and 72 h after application), the deposit was almost entirely crystalline. The addition of ‘Tween 20’ or of formulation blank resulted in the formation of a more amorphous, non-crystalline deposit. Herbicide solutions containing ammonium sulfate dried to form a highly crystalline deposit. However, crystals similar to those of glyphosate alone were not visible in these deposits. The ability of these adjuvants to prevent or delay crystal formation may play a role in their enhancement of herbicide uptake.     

Selected hormonal changes with summer fescue toxicosis

The effects of fescue endophyte content (low, 16 or high, 44% of tillers examined) and of N fertilization rate (low, 134 kg N.ha-1.yr-1 or high, 336 kg N.ha-1.yr-1) upon serum prolactin (PRL) in Angus steers were examined. Jugular blood samples for serum PRL determination were taken before (basal) and after thyrotropin releasing hormone (TRH) administration (stimulated). Areas under both the basal and stimulated PRL curves were calculated. While areas under the PRL curves varied with length of photoperiod, high endophyte content resulted in a consistent PRL suppression during 1984. During four time periods in 1984 (May to October), areas under the PRL curves [basal and(or) TRH stimulated] were suppressed (P less than .05) with high endophyte on three dates. Although basal areas under the PRL curves in 1983 were nonsignificantly suppressed with high endophyte, there was a suppression (P less than .05) post-TRH in October with high endophyte. There was no effect of N on PRL areas in either year. No relationship was found to exist between basal PRL areas and average daily gains as computed to encompass a period 2 wk before and after a blood collection date. Mean basal growth hormone (GH) concentration as determined from one bleeding date were elevated (P less than .05) in steers on high compared with low endophyte (7.9 and 6.2 ng/ml +/- 1.1 overall SE, respectively). There was no effect of treatment on TRH-stimulated serum GH values. Mean basal serum insulin values ranged from 13.2 to 17.5 microU/ml (+/- 1.2 overall SE) and were not affected by treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Trochlear recession for correction of luxating patella in the dog

Trochlear recession is a surgical technique for stabilizing luxating patellas by recessing the trochlear sulcus 1 to 2 mm. The smooth hyaline cartilage of the articulating trochlear surface is preserved. This technique has provided excellent results in 41 stifles of 28 dogs, as determined by a 6-month to 6-year follow-up, with an average follow-up period of 3.2 years.