A survey of practices and attitudes around cull cow management by bovine veterinarians in Ontario, Canada.

The removal (culling) of dairy cows from the farm is a regular and required management practice. The main objectives of this study were to describe the involvement of bovine veterinarians in Ontario, Canada, in dairy cull cow management decisions, their expectations of current producer practices, and their perspectives on welfare issues and best management practices for cull dairy cows. Between February and May 2021, a province-wide survey was conducted among all members of the Ontario Association of Bovine Practitioners (OABP), with questions addressing veterinarians' background and demographics, veterinary clinic characteristics, cull cow management, down cow management, and learning preferences. The response rate for the survey was 25.1%, with 45 responses meeting all eligibility criteria. Dairy veterinarians would like to have greater involvement in cull cow management; when asked for desired involvement in culling decisions, 57.5% of veterinarians would like to be involved in culling decisions most of the time or always. Most (70.0%) veterinarians believed that cull cow welfare has improved over the last decade. However, most respondents also identified at least one area of management (farm of origin, transportation, auction, slaughter) as currently being a high risk to cull cow welfare. Given the frequency of their visits, trust by dairy producers, and knowledge, herd veterinarians are among those in the best position to improve the care of cull dairy cows. Information generated from this survey can be used to inform the development of improved decision-making tools for culling cows, and this, along with increased veterinarians' involvement in cull cow management, could improve the economic and welfare outcomes of culling decisions for dairy producers.

A survey of dairy cattle farmers' management practices for cull cows in Ontario, Canada.

Removal of cows from dairy cattle production is a routine and unavoidable practice of the dairy industry and is often referred to as culling. The objectives of this study were to use a survey to describe current on-farm cull cow management, farmers' perception of cull cows' journeys to slaughter, and the adoption of current recommendations and regulations by Ontario dairy farmers. All Ontario dairy farmers were invited to complete a cull cow management survey between December 2020 and March 2021 that included 44 questions covering farmer demographic information, farm characteristics, and cull cow management. The survey response rate was 7.4% (n = 248); a total of 226 of the responses were included in this study for analysis. Most respondents indicated they have a written standard operating procedure (SOP) for cull cows (62%), and 48, 13, and 15% of those identified they use their cull cow SOP "always," "sometimes," and "never," respectively. The more confident respondents were that cull cows arrived at slaughter in the condition they left the farm the less likely they were to have a cull cow SOP [odds ratio (OR) 0.83]. The most important sources of information for the management of cull cows were the herd veterinarian (64%) and members of the marketing/regulatory organization the Dairy Farmers of Ontario (44%). Drug withdrawal time was the only factor most respondents (73%) considered "very important" for the assessment of cull cows prior to transport. Most farmers believe cull cows journey from the farm to slaughter is three or less days (55%), and the confidence of farmers that cull cows arrive at slaughter in the condition they left their farm was generally high. Lastly, most farmers (66%) identified they were familiar with recent regulatory changes around the fitness, duration of transport, and lactation status for cull cows. These results highlight farmers' perceptions of the impacts and durations of the journey of cull cows differs from reality, and there are misunderstandings of the requirements for cull cow management. Further research should investigate how different strategies for training farmers may lead to improved cull cow welfare and regulatory compliance.

Where are you from? Female mice raised in enriched or conventional cages differ socially, and can be discriminated by other mice.

Laboratory rodents raised in environmentally-enriched (EE) cages differ behaviourally and cognitively from conventionally-housed (CH) animals. We hypothesised that mice can detect such differences, testing this using differentially-raised female C57BL/6 s as subjects, and differentially-raised female BALB/cs and DBA/2 s as stimuli, in Social Approach Tests. Because more prone to signs of depression, anxiety, stereotypic behaviour (SB) and aggression, we further hypothesised that CH mice would be less sociable and socially attractive than EE mice. A novel familiarisation paradigm pre-exposed subjects to non-cagemate EE and CH stimulus mice before testing in Social Approach Tests. CH subjects proved less sociable than EE subjects: an effect unrelated to general exploration, anxiety or depression-like traits, and driven specifically by reduced interest in CH stimulus mice. Providing further evidence that CH and EE stimulus mice could be distinguished, subjects proved most attracted to mice from housing unlike their own. CH subjects thus preferred EE over CH stimulus mice, while EE subjects tended to prefer CH over EE: patterns that were not mediated by any measured aspect of stimulus mouse behaviour. Differential bodyweight also seemed unimportant, as was scent: soiled CH and EE bedding/nesting did not elicit the same discrimination. Instead, subjects who avoided CH stimulus mice and were attracted to EE stimulus mice were those who received the most agonism in their home cages. Together this provides the first demonstration that mice can distinguish between individuals raised in enriched or conventional cages, and suggests that receiving agonism from cagemates may motivate mice to seek new, less aggressive companions.

Assessing a Method of Mechanical Cervical Dislocation as a Humane Option for On-Farm Killing Using Anesthetized Poults and Young Turkeys.

Our objective was to determine the efficacy of manual cervical dislocation vs. a mechanical cervical dislocation device for on-farm killing of poults and young turkeys. Forty-two 1- and 3-week old turkeys were randomly assigned to one of three experimental groups: awake manual cervical dislocation (CD), anesthetized manual cervical dislocation (aCD), or anesthetized mechanical cervical dislocation (MCD). Anesthetized birds received an intramuscular dose of 0.3 mg/kg medetomidine and 30 mg/kg of ketamine to achieve a light plane of anesthesia. A comparison of CD vs. aCD responses indicated that the anesthetic plane did not affect jaw tone or pupillary light reflex, indicators of loss of sensibility and brain death, respectively. MCD was unsuccessful for killing 1-week old poults as indicated by the ongoing presence of the pupillary eye reflex as well as failure to achieve cardiac arrest within 5 min in 5 of 5 birds. Radiographs also indicated no vertebral dislocation or fracture. Pupillary light reflex was present in 98% and jaw tone was present in 73% of turkeys, respectively, for all groups combined, but retention of the pupillary light reflex (P < 0.001) and jaw tone (P = 0.001) was longer for birds killed by MCD. Time to last movement (P = 0.797) and cardiac arrest (P = 0.057) did not differ between method. Survey radiographs demonstrated an effect of method for the average displacement distance at the site of vertebral dislocation, with a greater distance observed in birds killed by CD compared to MCD (P = 0.003). A method by age interaction was observed between CD and MCD for the number of birds with fractures; more vertebral fractures were observed in 3-week old turkeys killed with MCD compared to CD (P = 0.047). Upon gross examination, the majority of birds killed by either method had minimal to no hemorrhage within the brain and spinal cord. However, turkeys killed using CD had more microscopic subdural brain hemorrhage (P = 0.020). Ante-mortem and post-mortem measures suggest that neither manual CD nor the MCD tool used in this study caused immediate insensibility, but CD resulted in a shorter latency to brain death and fewer fractures compared to MCD.