A B S T R A C TThe objective of this study was to identify risk factors for morbidity and mortality of bobby calves across the whole dairy supply chain in New Zealand. A case-control study was carried out in the 2016 spring calving season. A total of 194 bobby calves, comprising 38 cases (calves that died or were condemned for health or welfare reasons before the point of slaughter) and 156 controls (calves deemed acceptable and presented for slaughter) were included in the study. Case and control calves were selected by veterinarians located at 29 processing premises across New Zealand. Information regarding management of selected calves on-farm, during transport and at the processor was obtained retrospectively via questionnaires administered to supplying farmers, transport operators and processing premises personnel. Associations between management variables and calf mortality (death or condemnation) were examined using multivariable logistic regression models. Factors associated with an increased risk of calf mortality included time in the farm of origin's calving season, duration of travel from farm to the processor and processing slaughter schedule (same day or next day). Every additional week into the farm's calving season increased the odds of mortality by a factor of 1.2 (95%CI 1.06, 1.35). Similarly, each additional hour of travel time increased the odds of mortality by a factor of 1.45 (95% CI 1.18, 1.76). Risk of mortality was significantly greater for calves processed at premises with a next day slaughter schedule than those processed at premises with a same day slaughter schedule (OR 3.82, 95% CI 1.51, 9.67). However, when the data set was limited to those cases that died or were condemned in the yards (i.e. excluding calves that were dead or condemned on arrival) the effect of same day slaughter was not significant. In order to reduce bobby calf mortality and morbidity, transport duration should be kept as short as possible and a same day slaughter schedule applied. While these factors can be regulated, New Zealand's pastoral dairy system means that calves will inevitably be transported for slaughter across several months each spring. Although farm management factors did not apparently influence the risk of mortality in this study, the effect of time in farm's calving season suggests there may be farm-management related factors that change over the season. This requires further investigation.

The objective of this study was to evaluate the changes in electroencephalographic (EEG) power spectrum in response to decapitation of anaesthetized rats, in order to assess the nociception or otherwise of this procedure. Ten young adult male Sprague-Dawley rats were anaesthetized with halothane in oxygen and anaesthesia was maintained at a stable concentration of halothane between 1.20% and 1.25%. The rat's head and neck were placed through the opening of a small animal guillotine so that the blade of the guillotine was positioned over the atlanto-occipial joint of the rat's neck. The EEG was recorded in a five-electrode montage, bilaterally. After recording a 15 min baseline the rat was decapitated by swiftly pressing the guillotine blade and the EEG recording was continued until the signal was isoelectric on both channels. Changes in the median frequency (F50), 95% spectral edge frequency (F95) and total power of the EEG (Ptot) were used to investigate the effects of decapitation. During the first 15 s following decapitation, there were significant increases in the F50 and F95, and a decrease in the Ptot compared with baseline values. There was a clear window of time immediately following decapitation where changes in the EEG frequency spectrum were obvious; these changes in the EEG indices of nociception could be attributed as responses generated by the rat's cerebral cortex following decapitation.Keywords rat, electroencephalogram, euthanasia, welfare, nociception Several different methods of euthanasia have been proposed for use in laboratory animals in biomedical research (e.g. injectable anaesthesia, decapitation, cervical dislocation, CO 2 asphyxiation, etc.). 1Decapitation has the advantage that it has no effect on subsequent analytical procedures.2 This is not the case with chemical methods such as a drug overdose. Despite its common use, the humaneness of decapitation of conscious animals is debatable.2-5 The question of whether brain activity continues after decapitation and, if so, for how long, has been considered essential for determining the acceptability of this procedure. These questions have been addressed in a number of studies involving different animal species including rats.2,6-10 Studies utilizing electroencephalographic (EEG) recordings have been used to map the brain following decapitation. Conversion from high voltage slow activity to low voltage fast activity (LVFA) and desynchronization, a shift in EEG activity toward high frequency, have been reported as typical EEG responses following the decapitation of conscious animals. These changes in EEG activity persist between 8 and 29 s in all species after decapitation 5 and, are followed by the onset of isoelectric EEG.Interpretation of these post-decapitation EEG changes in terms of conscious arousal and potential pain perception, and as a response to noxious stimulation, has not been simple. Other studies have demonstrated that LVFA pattern EEG activity can be seen during rapid eye movement sleep/anaesthesia and also during an...

Little is known about the effects of inhalant anaesthetics on the avian electroencephalogram (EEG). The effects of halothane on the avian EEG are of interest, as this agent has been widely used to study nociception and analgesia in mammals. The objective of this study was to characterize the effects of halothane anaesthesia on the EEG of the chicken. Twelve female Hyline Brown chickens aged 8–10 weeks were anaesthetized with halothane in oxygen. For each bird, anaesthesia was progressively increased from 1–1.5 to 2 times the Minimum Anesthetic Concentration (MAC), then progressively decreased again. At each concentration, a sample of EEG was recorded after a 10‐min stabilization period. The mean Total Power (PTOT), Median Frequency (F50) and 95% Spectral Edge Frequency (F95) were calculated at each halothane MAC, along with the Burst Suppression Ratio (BSR). Burst suppression was rare and BSR did not differ between halothane concentrations. Increasing halothane concentration from 1 to 2 MAC resulted in a decrease in F50 and increase in PTOT, while F95 increased when MAC was reduced from 1.5 to 1. The results indicate dose‐dependent spectral EEG changes consistent with deepening anaesthesia in response to increasing halothane MAC. As burst suppression was rare, even at 1.5 or 2 times MAC, halothane may be a suitable anaesthetic agent for use in future studies exploring EEG activity in anaesthetized birds.

A thoracic squeeze has been observed to cause both healthy and low vigour neonatal foals to enter a ‘less-responsive state’, characterised by loss of posture, eye closure and cessation of movement, from which they rapidly recover to express normal healthy behaviours when the squeeze is released. To date, there have been no systematic studies characterising the responses of healthy neonates of other mammalian species to a thoracic squeeze. We describe the responses of healthy newborn piglets (n = 17) to a standardised application of the thoracic squeeze and evaluate the effect of the method of squeeze application on the response. Neonatal piglets were squeezed around the chest with either a soft fabric rope as has been used in foals (n = 8) or a novel purpose-made inflation cuff (n = 9). Both methods were effective at inducing a less-responsive behavioural state in all piglets, with neural reflexes reduced or absent in over half of them. The inflation cuff appeared to induce the less-responsive state faster than the rope, and more piglets squeezed with the cuff remained in this state for the full 10-min squeeze. These findings suggest that the behavioural response of foals to thoracic squeezing can be generalised to neonates of other precocial mammalian species. This initial study provides a foundation for further research using the inflation cuff to explore mechanisms underlying the thoracic squeeze and ways in which it may be applied whilst performing husbandry procedures.

Despite being a leading producer and exporter of dairy products, New Zealand has no industry-recognised welfare assessment protocol. A New Zealand-specific protocol is essential, as almost all dairy farms in New Zealand are pasture-based and housing is rarely used. Therefore, protocols developed for intensive cows are not suitable. The aim of this study was to develop a simple yet practical welfare assessment protocol that could be used to assess the welfare of a dairy herd during one visit timed to occur around milking. Six welfare assessment protocols and four studies of dairy cattle welfare assessments that had some focus on dairy cattle welfare at pasture were used, along with the New Zealand Dairy Cattle Code of Welfare, to identify potential assessments for inclusion in the protocol. Eighty-four potential assessments (20 record-based and 64 that needed assessing on-farm) were identified by this process of welfare assessments. After screening to exclude on-farm assessments that were not relevant, that had only limited practical application in pasture-based dairy cows or that required more time than available, 28 on-farm assessments remained, which were put together with the 20 record-based assessments and were tested for feasibility, practicality and time on two pasture-based dairy farms. Assessments were then identified as suitable, suitable after modification or not feasible. Suitable and modified assessments were then included in the final protocol alongside additional measures specific to New Zealand dairy farms. The final protocol included 24 on-farm assessments and eight record-based assessments. Further testing of these 32 assessments is needed on more dairy farms across New Zealand before the protocol can be used to routinely assess the welfare of dairy cows in New Zealand.