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1. The objective of this work was to investigate the feasibility of head only waterbath stunning as a means of generating immediate and long lasting unconsciousness while preventing wing flapping and avoiding carcass damage. 2. EEG measurements showed that immersion of the heads of the broilers for one second in a waterbath containing water of conductivity 2 x 5 mS/cm and a 50 Hz electric field of 10 V/cm resulted in immediate unconsciousness, and that increasing the electric field strength extended the duration of unconsciousness. 3. The passage of a 25-30 mA alternating current of frequency 2000 Hz through the broilers' bodies suppressed the wing flapping that followed a stun. 4. When the body current and electric field were applied simultaneously, wing flapping was prevented and EEG signals were suppressed for over 30 seconds indicating that the immediate unconsciousness lasted long enough to facilitate humane slaughter.

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The use of liquid carbon dioxide (CO(2)) was evaluated as a means of culling a flock of five-week-old pullets in situ. It took five minutes and 20 seconds for sufficient liquid CO(2) to be injected (3.24 tonnes) to achieve the target concentration of 45 per cent CO(2). Although very low ambient temperatures were recorded (below -80°C) during gassing, on the basis of postmortem reports and other data it is inferred that the birds died within minutes of exposure to the gas and before experiencing the extremely low temperatures recorded in the house.

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Prior to slaughter, most farmed birds move through a constant-voltage, multiple-bird, electrical water-bath stun system. Using this system subjects live birds to stressful and painful shackling, and the potential exists for them to receive prestun electric shocks and induction of seizures while still conscious. The existing electrical water-bath stunner settings, particularly those used in U.S. slaughter plants, are not necessarily based on sound scientific data that they produce a consistent, immediate stun, and research indicates that they are not effective in all birds. Further, in multiple-bird, electrical water-bath systems, birds may miss the stunner completely. Evidence suggests that some birds may still be alive when they reach the scald vat. For these reasons, electrical water-bath systems are increasingly under scrutiny on nonhuman-animal welfare grounds. Controlled Atmosphere Killing (CAK), a promising alternative technology, uses gas mixtures to render birds unconscious. CAK systems that stun birds while they are still in their transport crates avoid many of the welfare problems associated with the live-hang process and electrical water-bath stunning.

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1. A study was conducted to develop an in vitro model for examining the basal and electrical-stimulation-induced release of [3H]monoamines from chicken hyperstriatal neurones in order to demonstrate the presence of presynaptic autoreceptors for the three main monoamine transmitters: noradrenaline, dopamine and 5-HT. 2. Two sets of experiments were carried out: the first was to evaluate the effect of calcium and tetrodotoxin (TTX, sodium channel conductance inhibitor) in order to demonstrate that evoked release of monoamines was a consequence of exocytotic processes; the second to investigate the effect of selective agonists and antagonists on neurotransmitter release. 3. Ross and Cobb broiler chickens of either sex (approximately 7 to 8 weeks old) were used. Slices of hyperstriatal tissue were preincubated with [3H]noradrenaline, [3H]dopamine or [3H]5-hydroxytryptamine (5-HT), washed, perfused and electrically stimulated at three time points (S1, S2 and S3) which released [3H]noradrenaline, [3H]dopamine and [3H]5-HT, as determined by scintillation spectrometry. 4. When calcium was removed from, or TTX added to, the superfusion medium prior to and including the second period of electrical stimulation (S2) the evoked releases of [3H]noradrenaline, [3H]dopamine and [3H]5-HT at S2 were abolished. 5. In the presence of the selective alpha2-adrenoceptor agonist UK 14304 during the S2 period, the S2/S1 ratio was lower than the control ratio due to a reduction in the stimulated release of [3H]noradrenaline. The selective alpha2-adrenoceptor antagonist RX 821002 blocked the UK 14304-induced reduction of evoked release and the S2/S1 ratio was similar to the control ratio. 6. The D2-like receptor agonist quinpirole reduced the S2/S1 ratio for [3H]dopamine release, an effect blocked by the antagonist AJ 76. The 5-HT1B receptor agonist CP 94253 during S2 reduced the S2/S1 ratio due to a reduction in evoked [3H]5-HT. This effect was blocked by the 5-HT1B receptor antagonist GR 55562. 7. The results demonstrate, for the first time, the functional presence of presynaptic alpha2-adrenoceptors, presynaptic 5-HT1B autoreceptors and presynaptic D2-like autoreceptors in broiler chicken hyperstriatal neurones in vitro.

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We describe the management of a young boy with mild haemophilia A and a massive iliac pseudotumour with a multi modality approach involving factor replacement, radiation therapy, embolization and surgery. The patient was initially treated with recombinant factor VIII and radiation therapy. Because of inadequate response and worsening of bony erosion, the patient had a preoperative embolization followed by surgical excision. The surgical procedure was associated with minimal blood loss and the patient had a relatively smooth postoperative course with no physical morbidity. This case illustrates successful aggressive management of a large, proximally located pelvic pseudotumour, which resulted in an excellent outcome despite the need for a normally morbid operation.

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Poultry may need to be culled in the event of an outbreak of disease. Gassing has advantages over mechanical and electrical methods or overdoses of anaesthetics because large numbers can be killed simultaneously and little or no handling of the birds is required. However, gaseous killing methods may have welfare implications for the birds, which may find various gases more or less aversive, may undergo respiratory distress and/or experience convulsions, and may remain conscious for a considerable time before they die. In addition, the gases used may present health and safety risks to human operators, and be difficult to supply and deliver.

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1. The effectiveness of water bath electrical stunning of chickens with a constant root mean square (rms) current of 100 mA per bird delivered for 3 s using 100, 200, 400, 800 and 1500 Hz sine wave alternating current (AC) was investigated in layer hens. The quantitative changes occurring in the electroencephalogram (EEG) and somatosensory evoked potentials (SEPs) were used to determine the effectiveness of stunning. The changes occurring in the EEG were evaluated using Fast Fourier Transformations (FFT) and the SEPs were averaged to determine whether they were present or abolished. 2. The results of FFT indicated that stunning of chickens with a constant rms current of 100 mA per bird using 100 or 200 Hz induced epileptiform activity in all the hens, immediately followed by a reduction in the total (2 to 30 Hz) and relative (13 to 30 Hz) power contents in the EEG frequency bands indicative of unconsciousness and insensibility. The SEPs were abolished in the majority of hens stunned with 100 Hz and all the hens stunned with 200 Hz. 3. By contrast, stunning using 400, 800 or 1500 Hz failed to induce epileptiform activity in all the birds, the total and relative power contents in the EEG frequency bands showed a substantial increase, rather than reduction, and the SEPs were also retained in the majority of chickens. It is therefore suggested that stunning using these frequencies failed to stun them satisfactorily. In these birds, occurrence of a painful arousal, rather than unconsciousness, could not be ruled out. 4. It is therefore suggested that water bath electrical stunning of chickens with a minimum rms current of 100 mA per bird delivered using 100 or 200 Hz would be adequate to ensure bird welfare under commercial conditions, provided both the carotid arteries in the neck are severed at slaughter. On humanitarian and bird welfare grounds, a rms current of greater than 100 mA per bird should be applied whilst using frequencies of 400 Hz or more of sine wave AC for water bath electrical stunning of chickens.

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1. Two separate experiments were carried out in this study. In experiment 1, the effectiveness of stunning broilers, as determined from physical responses, with a 6 mm diameter bolt and an air line pressure of 827 kPa, when fired at 90 degrees (perpendicular to the skull) 110 degrees, 120 degrees and 130 degrees (leaning towards beak) was evaluated. 2. In experiment 2, the effects of perpendicular shooting with two bolt diameters (3 and 6 mm) and two air line pressures (620 and 827 kPa) on spontaneous behaviour, electroencephalogram (EEG) and visually evoked potentials (VEPs) were evaluated in broilers. 3. Only the perpendicular shooting was effective in stunning/killing broilers (n= 10) as indicated by the immediate cessation of breathing and loss of neck muscle tension and eye reflexes. Deviations from the perpendicular shooting failed to stun 5 out of 9 broilers. The perpendicular vs non-perpendicular effect was significant. 4. Shooting broilers with a 3 mm bolt at air line pressures of 620 kPa (n=2) or 827 kPa (n=2) failed stun as indicated by the unaltered physical reflexes, EEG and VEPs. Shooting of two broilers with a 6 mm bolt at 620 kPa resulted in effective stunning and a very rapid recovery of consciousness in one bird and death in the other. 5. Captive bolt stunning of broilers with a 6 mm bolt and air line pressure of 827 kPa resulted in an immediate stun leading to death in all 6 broilers tested. In these broilers, a profound EEG suppression and abolition of VEPs occurred immediately after shooting. 6. It is suggested that the appropriate variables for captive bolt stunning of broilers are a minimum of 6 mm bolt diameter driven at an air line pressure of 827 kPa and a penetration depth of 10 mm.

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1. Broiler chickens were killed using either an electrical waterbath (WB system) delivering 120 mA per bird (50 Hz, alternating current, AC) for 4 s or an alternative stun/kill method (ASK system); where head-only stunning for 1 s was immediately followed by head-to-body (vent) application for 1 s (150 mA, 50 Hz sine wave AC). Within each stun/kill system, the neck was cut ventrally or unilaterally 20, 60, or 180 s after killing. In addition, a control group of broilers was stunned with 100 mA per bird in a waterbath using 1500 Hz AC for 4 s and were bled by a ventral neck cut within 20 s. 2. Blood leaving the neck cut was collected for 90 s in a bin placed on an electronic balance and blood loss (g/kg body weight) calculated. 3. Individually identified, unplucked and uneviscerated carcases were held at ambient temperature until the end of the experimental day and then stored overnight in an air chiller (5 degrees C). The carcases were dissected and the incidence of broken furculum and coracoid bones, haemorrhaging in P. minor and P. major muscles, and discolouration of P. major muscles were determined. 4. When neck cutting was performed in broilers 20 s after the stun or kill, the ASK and WB systems, in comparison with high frequency stunning, produced on average about 10 g per kg less bleed out. Within the stun/kill systems, broilers killed by ASK had a greater bleed out than in the WB system. Neck cutting at 20 s or 60 s post-kill resulted in a greater bleed out than when performed after a delay of 180 s. Ventral or unilateral neck cutting resulted in a similar bleed out. 5. Stunning broilers with 1500 Hz AC resulted in lower incidences of broken bones, haemorrhaging in breast muscles and muscle discolouration post mortem than the stun/kill systems. These defects were significantly lower in the ASK than in the WB system. Delayed neck cutting increased the severity of discolouration occurring Post mortem in the breast muscles. 6. It is suggested that broilers killed by ASK can be neck cut with a delay of up to 180 s without compromising bleed out. The incidence of broken bones and haemorrhaging in breast muscles are significantly less with ASK than WB. 7. Owing to the commercial benefits and potential for improved welfare at slaughter, ASK would appear to be a better method than WB.

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We report increased numbers of hematogones in a 7-year-old girl with pancytopenia due to Shwachman-Diamond syndrome. Her hematogones expressed the T-cell marker CD5 as well as CD19, CD10, and CD20, and terminal deoxynucleotidyl transferase and HLA-DR. These findings suggest that hematogones are precursors of both CD5-positive B cells and CD5-negative B cells. Thus CD5-positive B cells in bone marrow may be derived from bone marrow stem cells, and not from the residual fetal B cells of yolk sac/liver origin. The finding of CD5 expression on hematogones also raises the possibility that neoplastic B cells of chronic lymphocytic leukemia, which characteristically co-express CD5 and CD19, may be derived from CD5-positive B-cell precursors in bone marrow and not from mature B cells in lymph nodes.

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Effect of electrical stunning on brain function in commercial rabbits was evaluated in electrophysiological studies. In addition to measuring duration of spontaneous physical activity and times to signs of recovery, electrocorticogram (ECOG) recordings and evoked responses were analysed following electrical stunning with 100 V for 1 s in eight rabbits. Epileptiform and other types of activity indicating insensibility were observed in the ECOG. Evoked responses were absent from 24 to 204 s following stunning. Application of a minimum current of 140 mA followed by prompt sticking should prevent welfare problems at stunning and slaughter in rabbits.

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1. The welfare and carcase quality implications of stunning/killing 7-week-old Japanese quail with either an electric current, 90% argon in air or a mixture of 30% carbon dioxide and 60% argon in air were investigated in 3 separate experiments. 2. The results showed that exposure of quail to either argon or the carbon dioxide-argon mixture resulted in loss of posture on average at 9 and 8 s respectively. In both gas mixtures, convulsions started 6 s after the loss of posture and the duration of clonic phase (wing flapping) did not differ significantly between the 2 gas mixtures. However, the duration of the tonic phase was found to be slightly longer with the carbon dioxide argon mixture than with argon alone (P<0.05). 3. The absence of a positive response to toe pinching performed soon after the loss of posture indicated that the birds became unconscious and insensible to pain before the onset of convulsions. 4. Carcase dissection showed that, in comparison with the electrical stunning, gas stunning/killing of quail in transport containers eliminated the problem of broken bones and significantly reduced haemorrhaging in breast and leg muscles.

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Pigs were exposed individually to either 90 per cent argon in air (anoxia), a mixture of 30 per cent carbon dioxide and 60 per cent argon in air (hypercapnic anoxia) or 80 to 90 per cent carbon dioxide in air (hypercapnic hypoxia) and the times to loss of posture, the onset and duration of convulsions, vocalisation and cessation of gagging (respiratory arrest) were determined. The duration of convulsions and the time to onset of respiratory arrest were longer when the pigs were exposed to argon than when they were exposed to the mixture of carbon dioxide and argon or to the high concentration of carbon dioxide in air. A second experiment was carried out under commercial conditions to determine the duration of unconsciousness and insensibility based on the response to a nose prick, and the incidence of death induced by exposing pigs to either 90 per cent argon in air or a mixture of 30 per cent carbon dioxide and 60 per cent argon in air for different periods. The results showed that when pigs were exposed for three minutes to either argon or the mixture of carbon dioxide and argon they should be bled within 25 seconds from the end of exposure to the gas to prevent them regaining consciousness during bleeding. When the pigs were exposed to either argon or the mixture of carbon dioxide and argon for five minutes and bleeding out began within 45 seconds they did not regain consciousness or suffer convulsions while being bled. The majority of the pigs died when they were exposed to argon for seven minutes, and all of them died when they were exposed to the mixture of carbon dioxide and argon for seven minutes.

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1. The feasibility of killing 7-week old Peking ducks with gas mixtures and their effects on carcase and meat quality were evaluated and compared with killing in electrical waterbath under commercial conditions. 2. The prevalence of carcase appearance defects and broken bones in the carcases and haemorrhaging, pH, colour, cooking loss and texture of breast muscles were determined. 3. Ducks can be killed within 3 min by exposure to either 90% argon in air or a mixture of 30% carbon dioxide and 60% argon in air. 4. Gas or controlled-atmosphere killing of ducks, whilst they are still in their transport containers, would eliminate some of the welfare concerns associated with the conventional electrical waterbath stunning systems, without adversely affecting carcase and meat quality.

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1. Six week-old broiler chickens implanted with electroencephalogram (EEG) recording and somatosensory stimulating electrodes were exposed to either 90% argon in air, a mixture of 30% carbon dioxide and 60% argon in air or a mixture of 30% oxygen and 40% carbon dioxide (balance nitrogen) for 2 min, to determine the times to onset of changes in spontaneous EEG and the loss of somatosensory evoked potentials (SEPs) and thus unequivocal loss of consciousness. 2. In addition, after a 2 min exposure to the carbon dioxide-oxygen mixture, some broilers were allowed to recover in air and their EEGs and SEPs were continuously recorded until the return of normal EEG and SEPs. During this period, the time to return of response to comb pinching was also determined in 10 broilers. 3. All broilers exposed to either argon or the carbon dioxide-argon mixture died within 2 min, whereas, only 3 out of 17 broilers died during the 2 min exposure to the carbon dioxide-oxygen mixture. 4. During exposure to argon, unlike the other 2 gas mixtures, the majority of broilers showed high amplitude, low frequency electrical activity in the EEG on average at 10 s. The mean times to onset of EEG suppression were 17, 19 and 40 s after exposure to argon, the carbon dioxide-argon mixture and the carbon dioxide-oxygen mixture, respectively. An isoelectric EEG occurred on average at 58 and 41 s after exposure to argon and the carbon dioxide-argon mixture, respectively. An isoelectric EEG did not occur in broilers which were exposed to the carbon dioxide-oxygen mixture. 5. The SEPs were abolished in broilers on average 32 and 24 s after exposure to argon and the carbon dioxide-argon mixture, respectively. During exposure of broilers to the carbon dioxide-oxygen mixture the SEPs were abolished in the majority of birds on average at 47 s, however, 2 out of 14 birds retained their SEPs for the entire period of 2 min exposure to this gas mixture. 6. During the recovery after exposure to the carbon dioxide oxygen mixture, response to comb pinching and SEPs returned either at the time of, or soon after, the onset of high frequency electrical activity in the suppressed EEG of broilers. The mean times to return of response to comb pinching and SEPs were 52 and 43 s, respectively. 7. Based on the time to onset of EEG suppression or loss of SEPs, exposure of broilers to either 90% argon in air, or a mixture of 30% carbon dioxide and 60% argon in air, resulted in quicker loss of consciousness than during exposure to a mixture of 40% carbon dioxide, 30% oxygen and 30% nitrogen. The time to return of consciousness after a 2 min exposure to the carbon dioxide-oxygen mixture was also found to be rapid.

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Electrical stunning was evaluated in commercial slaughter rabbits. Different voltage applications with varying current duration were tested in recovery experiments in 71 animals. Stunning parameters and duration of insensibility were measured and analysed for assessing stunning effectiveness. A minimum stunning current of 140 mA which can be achieved with application of 100 V was recommended.

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1. Carcase and meat quality were evaluated under commercial conditions in 400 broilers either killed with a mixture of 30% carbon dioxide and 60% argon in air or stunned with a 50 Hz AC with clipped sine wave. 2. Compared with electrical stunning, killing broilers with the gas mixture eliminated or substantially reduced the prevalence of carcase and meat quality defects. 3. The results also showed that killing broilers with a mixture of 30% carbon dioxide and 60% argon would enable filleting (deboning) to be performed at 4 h post mortem without adversely affecting the cook loss or texture of breast meat.

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