Alternatives to Carbon Dioxide in Two Phases for the Improvement of Broiler Chickens' Welfare during Stunning.

This study evaluated the exposure to gas mixtures of carbon dioxide (CO2) associated with nitrogen (N2) as alternatives to CO2 in two phases to improve the welfare of broiler chickens at slaughter. Broilers were exposed to one of three treatments: 40C90C (1st phase: <40% CO2 for 2 min; 2nd phase: >90% CO2 and <2% O2 for 2 min, n = 92), 40C60N (40% CO2, 60% N2, and <2% O2 for 4 min, n = 79), or 20C80N (20% CO2, 80% N2, and <2% O2 for 4 min, n = 72). Brain activity (EEG) was assessed to determine the onset of loss of consciousness (LOC) and death. Behavioural assessment allowed for characterisation of an aversive response to the treatments and confirmed loss of posture (LOP) and motionlessness as behavioural proxies of LOC and brain death in 40C60N and 20N80C. However, the lack of quality of the EEG traces obtained in 40C90C did not allow us to determine the onset of LOC and brain death for this treatment. The onset of LOC in 40C60N was found at 19 s [14-30 s] and in 20C80N at 21 s [16-37 s], whereas a LOP was seen at 53 s [26-156 s] in 40C90C. Birds showed brain death in 40C60N at 64 s [43-108 s] and in 20C80N at 70 s [45-88 s]), while they became motionless in 40C90C at 177 s [89-212 s]. The 40C90C birds not only experienced more events of aversive behaviours related to mucosal irritation, dyspnoea, and breathlessness during induction to unconsciousness but were at risk of remaining conscious when the CO2 concentration was increased in the 2nd phase (known to cause severe pain). From an animal welfare point of view, 40C60N proved to be the least aversive of the three treatments tested, followed by 20C80N and 40C90C.

Pre-Slaughter Stunning of Farmed Atlantic Halibut in CO2-Saturated Seawater: Assessment of Unconsciousness by Electroencephalography (EEG).

As fish welfare becomes a growing concern, it is important to ensure humane treatment during slaughter. This study aimed to assess the onset of unconsciousness in Atlantic halibut immersed in CO2-saturated seawater through electroencephalography (EEG). Of the 29 fish studied, 10 exhibited escape attempts, indicating aversion to CO2-saturated water despite its oxygenation. EEG signals showed four distinct phases: transitional, excitation (high amplitude-high frequency), suppressed, and iso-electric phases. The onset of the suppressed phase, indicative of unconsciousness, occurred on average 258.8 ± 46.2 s after immersion. The spectral analysis of the EEG signals showed a progressive decrease in median frequency, spectral edge frequency, and high frequency contribution, which corresponded to the gradual loss of consciousness. The study concludes that CO2-saturated water is not recommended for pre-slaughter handling of halibut due to the extended time required for the onset of unconsciousness and the observed aversive behaviour. Ensuring humane treatment during slaughter is important for addressing public concern and safeguarding fish welfare in all stages of production.

Perception of animal sentience by Brazilian and French citizens: The case of sheep welfare and sentience.

The study compared the perception of ordinary citizens from Curitiba, Brazil (OB) and Clermont-Ferrand, France (OF), as well as OB, Brazilian veterinarians (VB), biologists (BB) and animal scientists (AB), concerning animal welfare and sentience. An online survey containing 18 open-ended, multiple choices and Likert scale questions was conducted from November 2014 to May 2016. The survey covered questions on demographics, perception of animal welfare, sheep welfare, sentience and animals' emotional capacities. In total, 1103 respondents participated in the survey (388 OB, 350 OF, 248 VB, 92 BB and 25 AB); data were compared using non-parametric tests. Brazilian citizens (46.9%) believed more than OF (3.7%) that welfare is not considered for farm animals and OB attributed higher scores of suffering to sheep during management procedures (median 4, severe suffering) than OF (3, moderate suffering). Additionally, OB gave higher scores of emotions to animals (5) than OF (4). In general, OB and BB had similar perceptions; OB and BB differed from VB and AB who were similar to each other. Citizens (46.9%) and BB (29.3%) believed more than VB (18.5%) and AB (12.0%) that welfare is not considered for farm animals; OB and BB also attributed higher scores of suffering to sheep during management procedures than VB and AB. Women and older respondents showed higher perception of animal welfare issues. There was no clear correlation between perception of animal welfare or sentience and education. Overall, ordinary citizens differed on their perceptions of welfare and sentience in livestock and specifically in sheep, and sheep suffering during management procedures. Ordinary citizens from Curitiba showed higher perception of animal welfare issues as compared to respondents from Clermont-Ferrand and to veterinarians and animal scientists. Ensuring a better consideration of welfare at farm level and in educational programs seems warranted according to the results of this study.

Anesthetic use of eugenol and benzocaine in red tilapia (oreochromis sp.) / Uso anestésico de ugenol y benzocaína juveniles de tilapia roja (oreochromis sp.) / Eugenol e benzocaína como anestésicos em juvenis de tilápia vermelha (oreochromis sp.)

Abstract Background: routine practices such as biometrics, transportation and medical procedures are a source of stress to fish. The use of anesthetics is recommended to reduce undesirable effects of stress, such as decreased feed intake and even mortality -in critical cases. Objective: the aim of this study was to determine the anesthetic efficacy of eugenol and benzocaine in juveniles of red tilapia Oreochromis sp. Methods: juveniles of red tilapia (n=30), Oreochromis sp., were distributed in groups of 10 individuals as follows; G1: eugenol (50 mg/l), G2: eugenol (100 mg/l) and G3: benzocaine (100 mg/l). The fish were individually placed in the corresponding anesthetic solution. After immersion, times to achieve the different anesthetic stages were recorded. During anesthesia, the fish were measured, weighed and blood samples were collected for glucose and plasma cortisol analysis. Results: time to total loss of equilibrium was higher in G3 (p<0.05) compared to the other two groups. No significant differences were observed among groups regarding time to total loss of equilibrium or time to ventilation absence. Glucose levels were significantly higher in G1 (p=0.03) in comparison to G3. However, cortisol levels were higher in G3 as compared to the other groups (p<0.05). 10% mortality was observed in G1 fish. Conclusions: present findings indicate that 100 mg/l eugenol leads to induction of anesthesia in less than 3 minutes and recovery in less than 5 minutes, without mortality in juveniles of red tilapia.

Resumen Antecedentes: prácticas de rutina tales como biometría, transporte y procedimientos médicos representan una fuente de estrés para los peces. El uso de anestésicos está recomendado para contrarrestar los efectos nocivos del estrés, tales como disminución en el consumo de alimento y mortalidad en casos críticos. Objetivo: el presente trabajo buscó determinar la eficacia anestésica del eugenol y benzocaína en juveniles de tilapia roja Oreochromis sp. Métodos: en este estudio fueron utilizados 30 juveniles de tilapia roja (Oreochromis sp.) distribuidos en grupos de 10 individuos como sigue; G1: eugenol (50 mg/l), G2: eugenol (100 mg/l) y G3: benzocaína (100 mg/l). Los peces fueron ubicados individualmente en la solución anestésica correspondiente. Después de la inmersión fueron medidos los tiempos para alcanzar los diferentes planos anestésicos. En el tiempo de anestesia, los peces fueron medidos, pesados y colectadas muestras de sangre para análisis de glucosa y cortisol plasmático. Resultados: el tiempo de pérdida del eje de nado fue mayor en el G3 (p<0.05). No se encontraron diferencias significativas entre los grupos en el tiempo de recuperación del eje de nado y en el tiempo de ausencia de movimientos operculares. Los niveles de glucosa fueron significativamente mayores en los animales del G1 (p=0.03) respecto al G3. Sin embargo, los niveles de cortisol fueron mayores en el G3 respecto a los otros grupos (p<0.05). Se observó un porcentaje de mortalidad del 10% en los ejemplares del G1. Conclusiones: los resultados sugieren que el eugenol a una concentración de 100 mg/l lleva a una inducción anestésica menor a 3 minutos y recuperación menor a 5 minutos sin mortalidad en juveniles de tilapia roja.

Resumo Antecedentes: os procedimentos de rotina tais como a biometria, transporte e procedimentos clínicos são uma fonte de estresse para os peixes. O uso de anestésicos está recomendado para diminuir os efeitos nocivos do estresse, como por exemplo, a diminuição no consumo de alimento e em casos críticos mortalidade. Objetivo: o presente trabalho buscou determinar a eficácia anestésica do eugenol e da benzocaína em juvenis de tilápia vermelha Oreochromis sp. Métodos: neste estudo foram utilizados 30 juvenis de tilápia vermelha (Oreochromis sp.) distribuídos em grupos de 10 indivíduos de acordo ao anestésico utilizado; G1: eugenol (50 mg/l), G2: eugenol (100 mg/l) e G3: benzocaína (100 mg/l). Os animais foram passados pela solução anestésica correspondente, na qual se mediram tempos para atingir os diferentes estádios de anestesia. No tempo de anestesia, os peixes foram medidos, pesados e coletadas amostras do sangue para análise de glicose e cortisol plasmático. Resultados: o tempo de pérrdida do eixo de nado foi maior no G3 (p<0.05). Não se encontraram diferenças significativas entre os grupos no tempo de recuperação do eixo de nado e no tempo de ausência de movimentos operculares. Os níveis de glicose foram significativamente maiores nos animais do G1 (p=0.03) respeito ao G3. No entanto, os níveis de cortisol foram maiores no G3 em relação a os outros grupos (p<0.05). Observou-se um percentual de mortalidade de 10% nos exemplares do G1. Conclusão: os resultados sugerem que o eugenol a 100 mg/l provoca uma indução anestésica menor a 3 minutos e uma recuperação menor a 5 minutos sem mortalidade em juvenis de tilápia vermelha.

Perception of Fish Sentience, Welfare and Humane Slaughter by Highly Educated Citizens of Bogotá, Colombia and Curitiba, Brazil.

Discussions on farm animal welfare have become frequent, especially in developed countries. The aim of this research was to study the perception of fish sentience, welfare and slaughter by highly educated citizens from Bogotá, Colombia, and Curitiba, Brazil. An online survey with 12 questions presented as open-ended, multiple choice and 5-point Likert-type scale formats was available to respondents. Answers from 395 participants in Bogotá and 387 in Curitiba were analyzed, and results are presented in the order Bogotá followed by Curitiba. The percentage of participants who perceived fish as sentient animals was 79.7% and 71.8%. The classification of sentience perception among taxonomic groups seems in accordance with the phylogenetic proximity to humans, suggesting participants were more likely to perceive sentience in mammals than in other animals. The descending order related to the highest perception of fish suffering in different scenarios was fishing with hook and line (75.6%, 70.6%); municipal live fish fair (68.7%-only in Curitiba); fish-and-pay ponds (59.7%, 54.4%); fish kept as laboratory animals (58.0, 48.1%); fish farming (35.7, 36.8%); fish in pet stores (35.5%, 26.1%); production of ornamental fish (19.3%, 21.8%); fish in aquarium exhibits (18.8%,16.9%); and fish kept as pets (12.4%,12.3%). Lack of knowledge about the conditions of capture, handling, transport and sale of ornamental fish may justify the perception of low level of suffering in the last scenarios. Regarding humane slaughter, 57.0% and 55.0% of respondents were unaware of the issue. After reflection induced by the questionnaire, 76.0% and 72% of participants believed that fish should be included in humane slaughter regulations. This study presents original data suggesting that respondents from Bogotá and Curitiba consider fish as sentient beings. The perception of suffering in specific scenarios challenges common activities. Recognition of suffering also endorses humane slaughter regulations to reduce pain in a large number of individuals of fish slaughtered annually for human consumption in Colombia and Brazil.