Attitudes of laboratory animal professionals and researchers towards carbon dioxide euthanasia for rodents and perceived barriers to change

Evidence indicates that carbon dioxide (CO₂) induces negative affective states (including anxiety, fear and distress) in laboratory rodents, but many countries still accept it for euthanasia. Alternative methods (e.g. inhalant anaesthetic) may represent a refinement over CO₂ but are not widely adopted. We conducted an online survey of Canadian and European laboratory animal professionals and researchers (n = 592) to assess their attitudes towards the use of CO₂ and alternative methods for rodent euthanasia using quantitative 7-point scale (from 1 (= strongly oppose) to 7 (= strongly favour) and qualitative (open-ended text) responses. CO₂ was identified as the most common method used to kill rodents, and attitudes towards this method were variable and on average ambivalent (mean ± SD score on our 7-point scale was 4.4 ± 1.46). Qualitative analysis revealed four themes relating to participant attitude: (a) the animal’s experience during gas exposure; (b) practical considerations for humans; (c) compromise between the animal’s experience and practical considerations; and (d) technical description of the procedure or policies. Many participants (51%) felt that there were alternatives available that could be considered an improvement over CO₂, but perceived barriers to implementing these refinements. Qualitative analysis of these responses revealed five themes: (a) financial constraints; (b) institutional culture; (c) regulatory constraints; (d) research constraints; and (e) safety concerns. In conclusion, concerns regarding the use of CO₂ often focused on the animal’s experience, but barriers to alternatives related to operational limitations. New research is now required on to how best to overcome these barriers.

Perspectives of Western Canadian dairy farmers on providing outdoor access for dairy cows

Dairy cows are highly motivated to access pasture, especially at night in summer. When pasture is not available, dairy cows show a partial preference for alternative types of outdoor access, spending half the night outside in summer on an outdoor sand or wood chip pack. However, many dairy farms do not provide cows outside access. To better understand reasons why dairy farmers choose to provide or not provide outdoor access, we studied the perspectives of dairy farmers located in the 4 Western Canadian provinces: British Columbia, Alberta, Saskatchewan, and Manitoba. Data were collected via (1) 11 focus group discussions with a total of 50 Western Canadian dairy farmers, and (2) semi-structured individual interviews with 6 dairy farmers of Hutterite colonies. Transcripts were analyzed using template analysis. Reasons to not provide outdoor access fell into 5 main themes: (1) adverse climate conditions, (2) negative implications of outdoor access for cow welfare including concerns about udder health, (3) concerns regarding decreases in profitability, (4) farm infrastructure not set up for outdoor access, and (5) higher ability to manage animals kept indoors. Reasons to provide outdoor access fell into the 5 main themes: (1) local climate conditions conducive for outdoor access, (2) beneficial effects of outdoor access on cow welfare including lower lameness prevalence, (3) increased profitability due to a premium milk price provided to farmers that allow pasture access to their cows, (4) farm infrastructure that is set up for outdoor access, and (5) easier management of animals outdoors. We conclude that the decision to provide outdoor access depends on how farmers weigh these factors given the constraints on their farm, as well as their personal beliefs and values.

Differences in the fecal microbiota of dairy calves reared with differing sources of milk and levels of maternal contact

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We compared fecal microbiota in dam-reared and conventionally reared dairy calves, which were fed whole milk and waste milk, respectively.

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Dairy calves reared with dam contact had higher relative abundance of Lactobacillus.

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Conventionally reared calves had higher concentrations of taxa such as Bacteroides.

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Dam-reared calves were predicted to have higher levels of l-tryptophan biosynthesis.

The practice of rearing cows and calves together is gaining popularity on dairy farms, with different systems currently under assessment in mainland Europe, the United Kingdom, and Oceania. Research into the effects of cow–calf rearing has primarily focused on direct health and welfare implications, and little work has examined the role of different rearing paradigms on calf microbiota. We trialed a cow–calf rearing system on a Canadian dairy farm and compared fecal microbiota of these calves with the microbiota of calves reared according to the conventional practice of the same farm (separated from the dam and fed waste milk). At 4 wk, the conventionally reared calves had reduced relative abundance of Lactobacillus and higher relative abundance of other taxa, including Sutterella, Prevotella, and Bacteroides. We also detected predicted functional differences, such as reduced l-tryptophan biosynthesis in conventionally reared calves. These results suggest that maternal contact may influence the calf microbiota, but the observed differences are also likely related to other aspects of the rearing environment independent of maternal contact (e.g., potential exposure to antibiotic residues in waste milk). These findings provide preliminary evidence of the effects of early rearing environments on the establishment of the dairy calf fecal microbiota. This research is needed, given the critical role of the bovine gut microbiome in behavioral, metabolic, and immune development.

A break from the pups: The effects of loft access on the welfare of lactating laboratory rats

Rats (Rattus norvegicus) bred for research are typically confined with their litters until weaning, but will spend time away from pups when given the opportunity. We aimed to assess how dam welfare is affected by the ability to escape from their pups. Rat dams (n = 16) were housed in cages either with or without an elevated loft. We measured time dams spent in lofts, time spent nursing, and affective states using elevated plus maze and anticipatory behavior testing. We predicted that 1) dams housed with lofts would use them increasingly as pups aged, 2) dams without a loft would spend more time passively nursing (i.e. initiated by pups rather than the dam) and more total time nursing as pups aged, and 3) dams housed with lofts would show evidence of a more positive affective state. Dams housed with lofts spent more time in the loft with increasing pup age; dams spent on average (mean ± SE) 27 ± 5% of their time in the loft when pups were 1 wk old, increasing to 52 ± 5% of their time at 3 wks. When pups were 3 wks old, dams with lofts spent less time passively nursing (10 ± 2% of total time, compared to 27 ± 4% for dams without a loft) and less time nursing overall (36 ± 4% of time versus 59 ± 2% for dams without a loft). Rats without loft access showed increased anticipatory behavior potentially indicative of negative affective state (24.5±1.8 behaviors per minute in wk 3 compared to 18.8±1.0 in wk 1). These findings indicate that rat dams in laboratories choose to spend time away from their pups when provided the opportunity, particularly later in lactation; an inability to do so is associated with increased passive nursing and negative affect.

The Freestall Reimagined: Effects on Stall Hygiene and Space Usage in Dairy Cattle

Modern freestall barns for dairy cattle have been constructed with considerations for dairy cow cleanliness; partitions and other stall features such as neck rails are designed to reduce manure contamination of bedding and decrease farm labor. However, cows prefer to lie in more open spaces, including on bedded packs and pasture. We created an "alternative" housing area by modifying a traditional freestall pen and including flexible partitions to create larger lying areas. We assessed cattle lying behaviour, including lying postures, in this alternative pen (ALT) compared to an open pack (OP) and freestalls (FS) with different stocking densities. We also assessed levels of manure contamination across systems. Cleanliness was highest in FS, but ALT provided substantial improvement compared to OP. Cattle spent more time lying down in OP and ALT compared to FS. There were few differences in postures (such as lying with limbs outstretched) between OP and ALT, but cows in both of these systems more often lay in extended positions compared to when they were housed in FS. Housing in OP and ALT was associated with reduced perching for cows with high body weight; perching has been linked to an increased prevalence of both hoof lesions and lameness. Thus, alternative lying areas can offer a solution for producers seeking to provide cattle with the advantages of a more open lying area, while improving hygiene relative to an open pack.

Using Realistic Evaluation to understand how interventions work on dairy farms

Interventions that aim to help farmers change on-farm practices recommend that advisors communicate effectively with farmers, work collaboratively to set goals and provide farmers with resources that are applicable to the farm context. We developed an intervention that aimed to help farmers modify and use a standard operating procedure (SOP) for colostrum management; failure of passive transfer of immunoglobulins is common on dairy farms and SOPs for colostrum management are increasingly required by farm animal welfare assurance programs. We used Realistic Evaluation to evaluate whether, how and why our intervention to help farmers modify and use SOPs for colostrum management facilitated change and provide recommendations based on our approach that can improve the design and implementation of future interventions. We used a multiple case study on five farms over 8 months, collecting data through interviews, participant observation, document analysis and field notes. We identified three mechanisms that influenced whether participants modified and used their SOP. The purpose mechanism distinguished between participants who thought the aim of the SOP was for farm staff to learn and understand how to complete a task versus those who thought that the SOP was only useful for compliance with assurance programs. The utility mechanism distinguished between participants who thought that the SOP would be helpful for daily use on their farm, versus those who did not. The physical text mechanism distinguished between participants who used the templates we provided to modify and use their SOP, versus those who did not. A key contextual factor on all farms was participant belief of having capable and engaged staff on their farm; modification and use of the SOP did not occur unless this was the case. To facilitate change, intervention developers should actively participate in the intervention to develop an understanding of farmer needs, understand the purpose behind different goals set by farmers and integrate tools, advice and resource demonstrations when possible. We conclude that Realistic Evaluation is a useful framework for evaluating how contexts and mechanisms generate outcomes on farms, and to understand how, and in which contexts, complex interventions facilitate change. We suggest that this approach can improve the success of interventions and help direct the approaches used on different farms.

Public attitudes toward dairy farm practices and technology related to milk production

Dairy farm systems have intensified to meet growing demands for animal products, but public opposition to this intensification has also grown due, in part, to concerns about animal welfare. One approach to addressing challenges in agricultural systems has been through the addition of new technologies, including genetic modification. Previous studies have reported some public resistance towards the use of these technologies in agriculture, but this research has assessed public attitudes toward individual practices and technologies and few studies have examined a range of practices on dairy farms. In the present study, we presented participants with four scenarios describing dairy practices (cow-calf separation, the fate of excess dairy calves, pasture access and disbudding). Citizens from Canada and the United States (n = 650) indicated their support (on a 7-point scale) toward five approaches (maintaining standard farm practice, using a naturalistic approach, using a technological approach, or switching to plant-based or yeast-based milk production) aimed at addressing the welfare issues associated with the four dairy practices. Respondents also provided a text-based rationale for their responses and answered a series of demographic questions including age, gender, and diet. Participant diet affected attitudes toward milk alternatives, with vegetarians and vegans showing more support for the plant-based and yeast-based milk production. Regardless of diet, most participants opposed genetic modification technologies and supported more naturalistic practices. Qualitative responses provided insight into participants’ values and concerns, and illustrated a variety of perceived benefits and concerns related to the options presented. Common themes included animal welfare, ethics of animal use, and opposition toward technology. We conclude that Canadian and US citizens consider multiple aspects of farm systems when contemplating animal welfare concerns, and tend to favor naturalistic approaches over technological solutions, especially when the latter are based on genetic modification.

Views of American animal and dairy science students on the future of dairy farms and public expectations for dairy cattle care: A focus group study

Students completing advanced degrees in dairy or animal science may go on to have a major impact on the food animal agriculture industries. The aim of this study was to better understand student views of the future of dairying, including changes in practices affecting animal care on farms as well as perceived public perceptions. We conducted 6 focus group sessions with undergraduate students enrolled in the 2019 US Dairy Education and Training Consortium held in Clovis, New Mexico, and used explorative key word analysis of written notes and thematic analysis of the semi-structured discussions. Some "must-haves" of future animal care on dairy farms included increased use of technology, group housing of calves, and adequate facilities, including enrichment. Students also discussed their views of public expectations regarding animal care on dairy farms, and measures that they felt must be put into place to address these expectations in the coming years. Although the influence of the public was highlighted by the students, they were not always certain what specific values the public holds and doubted the feasibility and practicality of some expectations, such as providing pasture access or keeping the calf and cow together. They further demonstrated uncertainty about how best to align the directions of the industry with public expectations. Although they felt that public education could be used to demonstrate the legitimacy of dairy practices, they also believed that the industry should strive to find compromises and work toward meeting public expectations. Deciding what animal welfare considerations (e.g., naturalness, affective states, or animal health) were most relevant was a challenge for the students, perhaps reflecting diverging messages received during their own education.

Pairwise comparison locomotion scoring for dairy cattle

Conventional locomotion scoring is a subjective, absolute, and discrete assessment of locomotion. Here we assess pairwise comparison scoring to improve upon the limited intra- and interobserver consistency typical of conventional locomotion scoring. Five observers performed conventional 4-level locomotion scoring using 50 video recordings of dairy cattle, and also assessed 90 pairs of videos (composed from the same 50 recordings) using relative pairwise scoring. Intra- and interobserver consistency of pairwise scores [intraobserver: percentage agreement (PA) = 82%, κ = 0.63; interobserver: PA = 79%, κ = 0.57] were greater than of 4-level absolute scores (intraobserver: PA = 72%, κw = 0.74; interobserver: PA = 56%, κw = 0.59). Pairwise scores were scaled with an optimization method to obtain the position of the 50 recordings on a continuous locomotion scale. These continuous locomotion scores (CLS) were compared with the conventional mean absolute visual locomotion scores (VLS). Correlation between CLS and VLS was strong (τ = 0.69), and consistency between binarized CLS and binarized VLS was high (PA = 84%, κ = 0.66 for threshold VLS ≥1). Just noticeable difference (JND) for locomotion scoring was 0.3 on a 4-level scale ranging from 0 to 3. Pairwise scoring and scaling had the scoring consistency of binary absolute scoring with finer continuous granularity than 4-level absolute scoring. The pairwise scoring method, and associated scaling, offer a more consistent and informative alternative to conventional absolute multilevel locomotion scoring.

Effects of positive reinforcement training for heifers on responses to a subcutaneous injection

Cattle are subjected to routine procedures that require restraint and close contact to humans, which are both potentially aversive to the animal. Positive reinforcement training techniques may affect how animals perceive and respond to these procedures. The objectives of the current study were to describe a positive reinforcement regimen used to train cattle to stand still for a sham injection, and to assess the effects of this training on the responses to an actual injection. Eight "agency" heifers were trained, over an average of 85 ± 4.6 sessions, with positive reinforcement (i.e., animals received a grain reinforcer for desired behaviors) to enter a headlock, and they were habituated with counterconditioning and desensitization to a sham injection (i.e., animals were gradually exposed to the sensation of the sham injection, paired with access to grain). The headlock remained open at all times to allow heifers to leave. Eight "habituation" heifers were exposed to the treatment area and headlock for an equal number of sessions and duration as agency heifers, and 7 "naïve" heifers were provided no exposure to the treatment area. Once agency heifers tolerated the sham injection, all animals received a 1-mL subcutaneous injection of 0.9% NaCl while in the head lock (habituation and naïve heifers were locked in but agency heifers were free to withdraw). Immediate responses to the injection, starting with tenting of the skin, were video recorded and summarized as a reactivity score, which included the number of steps, head tosses, and backing-up movements; we also recorded the latency to approach the treatment area and headlock for 3 d after the injection. Of the agency heifers, 5 remained standing for the actual injection, whereas 3 heifers moved out of the headlock for a brief period (1, 3, and 5 s, respectively). Habituation heifers had a higher reactivity score [17.5 (10.5-28); median (IQR)] than agency [6 (2-13.5)] and naïve heifers [6 (5-7)]. Averaged over the 3 d after injection, agency heifers showed lower latencies to come to the treatment area [8.7 (7.2-24.2) s] than did habituation [50.5 (28-60) s] and naïve [53.7 (18-60) s] heifers. Agency heifers voluntarily entered the headlock within 1.3 (1-1.5) s but, with one exception, none of the other heifers did so within the allowed 15 s. These results indicate that dairy heifers can be trained with positive reinforcement and counterconditioning to voluntarily accept a painful procedure, and that training can reduce avoidance behaviors during and after the procedure.

Facial expression in humans as a measure of empathy towards farm animals in pain

People often express concern for the welfare of farm animals, but research on this topic has relied upon self-report. Facial expressions provide a quantifiable measure of emotional response that may be less susceptible to social desirability bias and other issues associated with self-report. Viewing other humans in pain elicits facial expressions indicative of empathy. Here we provide the first evidence that this measure can also be used to assess human empathetic responses towards farm animals, showing that facial expressions respond reliably when participants view videos of farm animals undergoing painful procedures. Participants (n = 30) were asked to watch publicly sourced video clips of cows and pigs undergoing common management procedures (e.g. disbudding, castration, tail docking) and control videos (e.g. being lightly restrained, standing). Participants provided their subjective rating of the intensity of 5 negative emotions (pain, sadness, anger, fear, disgust) on an 11-point Likert scale. Videos of the participants (watching the animals) were scored for intensity of unpleasantness of the participants' facial expression (also on an 11-point Likert scale) by a trained observer who was blind to treatment. Participants showed more intense facial expressions while viewing painful procedures versus control procedures (mean ± SE Likert; 2.4 ± 0.08 versus 0.6 ± 0.17). Participants who reported more intense negative responses also showed stronger facial expressions (slope ± SE = 0.4 ± 0.04). Both the self-reported and facial measures varied with species and procedure witnessed. These results indicate that facial expressions can be used to assess human-animal empathy.

Individual differences in rat sensitivity to CO2

Feelings of fear, anxiety, dyspnea and panic when inhaling carbon dioxide (CO2) are variable among humans, in part due to differences in CO2 sensitivity. Rat aversion to CO2 consistently varies between individuals; this variation in aversion may reflect CO2 sensitivity, but other personality traits could also account for individual differences in aversion. The aims of this study were to 1) assess the stability of individual differences in rat aversion to CO2, 2) determine if individual differences in sweet reward motivation are associated with variation in aversion to CO2, and 3) assess whether variation in aversion to CO2 is related to individual differences in motivation to approach gains (promotion focus) or maintain safety (prevention focus). Twelve female Sprague Dawley rats were exposed multiple times at three different ages (3, 9 and 16 months old) to CO2 in approach-avoidance testing to assess motivation to avoid CO2 against motivation to gain sweet rewards. Rats were also tested for motivation to find hidden sweet rewards, and for their motivation to approach rewards or darkness. Tolerance to CO2 increased with repeated exposures and was higher at older ages. Individual differences in aversion to CO2 were highly repeatable but unrelated to motivation for sweet rewards or the strength of promotion and prevention focus. These results indicate that individual differences in aversion to CO2 reflect variation in CO2 sensitivity.

Addition of straw to the early-lactation diet: Effects on feed intake, milk yield, and subclinical ketosis in Holstein cows

This study evaluated feed intake, milk yield, and subclinical ketosis in dairy cows in early lactation fed 2 different diets postpartum. Cows are typically offered a high-energy ration immediately after calving. We compared a conventional high-energy total mixed ration (TMR) with a transition ration that contained chopped straw. We predicted that adding chopped straw would increase dry matter intake, milk production, and indicators of energy metabolism during the first 3 wk of lactation compared to cows fed a conventional high-energy TMR. We also predicted that carryover effects would be likely for at least 2 wk after treatment ended. A total of 68 mixed-age Holstein cows were enrolled in the study 3 wk before their expected calving. All cows were managed on a single high-forage diet during the dry period. At calving, cows were allocated to 1 of the 2 diets: half to the conventional high-energy TMR (CTMR; n = 34; net energy for lactation = 1.61 Mcal/kg; neutral detergent fiber = 31.7%), and the other half to a high-forage TMR containing chopped wheat straw, equivalent to 4.27% dry matter (STMR; n = 34; net energy for lactation = 1.59 Mcal/kg; neutral detergent fiber = 33.7%) for 3 wk after calving. Cows on STMR were then shifted to CTMR for the next 2 wk to study short-term residual effects on the performance of cows. Treatments were balanced for parity, body condition score, and body weight. Feed intake was measured daily from 2 wk before to 5 wk after calving using automatic feed bins. Blood was sampled twice weekly from 2 wk before to 5 wk after calving, and β-hydroxybutyrate and glucose were measured in serum samples. Subclinical ketosis was identified using a threshold of β-hydroxybutyrate ≥1.0 mmol/L in wk 1 after calving and ≥1.2 mmol/L in wk 2 to 5 after calving. Cows were milked twice daily, and weekly samples (composite samples of morning and afternoon milkings) were analyzed to determine total solids, fat, protein, lactose, and somatic cell count. Data were analyzed in 2 separate periods: the treatment phase (wk +1, +2, and +3) and the post-treatment phase (wk +4 and +5). The addition of straw to the TMR negatively affected the dry matter intake of STMR cows during wk 2 and 3 of lactation. Daily milk yield during the first 5 wk of lactation was lower in STMR cows than in CTMR cows. Concentrations of β-hydroxybutyrate were higher in CTMR cows than in STMR cows during wk 1, but this effect was reversed during wk 2 and 3 of lactation. By 21 d in milk, STMR cows had a greater risk of developing subclinical ketosis than CTMR cows. Adding chopped wheat straw to the TMR during the first 21 d after calving lowered dry matter intake and provided no metabolic or production benefits to lactating dairy cattle.

The effects of social environment on standing behavior and the development of claw horn lesions

The primary aim of this prospective experimental study was to evaluate how the social environment after calving influenced standing behavior in primiparous cows. At calving, primiparous cows were mixed with familiar peers in a low-stocked pen (≤33% stocking density; n = 22) or mixed with unknown older cows at 100% stocking density (n = 20). All study cows were mixed with older cows 3 wk after calving. Time spent standing and perching (standing with only the front feet in the stall) were measured d 1 to 3 after calving using 5-min scan sampling. To evaluate if the low-stocked treatment constituted a low-stress social environment, agonistic interactions at the feed barrier were measured for 90 min following feed delivery for a subsample of cows in both treatments (12 cows/treatment). The daily behavioral time budget, including the 90 min following milking, was examined for this subset of cows. A secondary aim was to assess if the social environment after calving was related to the risk of developing claw horn lesions later in lactation. Sole and white line lesions were recorded at wk 6 and 12 after calving, and cows were categorized as either having or not having at least 1 hemorrhage of severity ≥3 (scale 1 to 5) for each lesion type and assessment. Prolonged standing after regrouping was not observed, and we found no differences in standing time and time spent perching between treatments. Agonistic behaviors directed toward the focal cows occurred less frequently in the low-stocked pen compared with the control. The number and severity of sole and white line lesions increased after calving. At wk 6 postpartum there was a numeric (but not statistically significant) difference between treatments in the proportion of primiparous cows that had white line hemorrhages of severity score ≥3 (low-stress social environment: 20% vs. control: 50%). In conclusion, under the conditions of this study the social environment did not influence standing behavior, but did affect agonistic interactions and may have influenced the risk of claw horn lesions in the weeks following calving. Further studies should evaluate the relationship between the social environment and claw health.

Pessimistic dairy calves are more vulnerable to pain-induced anhedonia

Pain induces deficits in appreciation of rewards (i.e. anhedonia) and variation in response to pain may be partly explained by individual differences in general expectations (i.e. optimism). Dairy calves are routinely subjected to painful procedures such as hot-iron disbudding. We tested if female Holstein calves (n = 17) display signs of anhedonia (as evidenced by reduced consumption of a sweet solution) after hot-iron disbudding (performed under general and local anesthesia), and whether individual differences in optimism explain the variation in this response. Individual variation in optimism was measured using responses to two judgment bias tests (performed when calves were 25 d old), and anhedonia was measured by comparing consumption of a sweet solution before and after hot-iron disbudding. We found that intake of the sweet solution declined (by mean ± SD: 48.4 ± 44.3%) on the day after disbudding, and that more pessimistic calves were more affected. Sweet solution consumption did not return to baseline for the duration of the study (i.e. 5 days). Calves reduced their intake of a sweet solution after hot-iron disbudding, consistent with pain-induced anhedonia, and more pessimistic calves showed stronger evidence of anhedonia, suggesting that they were more affected by the procedure. However, our results cannot rule out the possibility that calf responses were driven by anorexia.

Regrouping induces anhedonia-like responses in dairy heifers

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Regrouping is a stressful experience for cattle

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Reduced ability to experience pleasure (anhedonia) indicates negative mood state

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We measured changes in brush use to assess anhedonia in 6-mo-old heifers

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Regrouping resulted in reduced brush use, indicative of low mood

Intensively housed dairy cattle are commonly regrouped (mixed into a new social group) as part of routine farm procedures. This stressful procedure triggers heightened levels of agonistic behaviors and disrupts animals' time budgets. However, little is known regarding the effects of regrouping on cattle's affective states. The aim of this study was to explore whether regrouping (involving a change in both the social and physical environment) triggers anhedonia (i.e., the reduced ability to experience pleasure) in 6-mo-old dairy heifers, a phenomenon associated with negative mood. In this study, we assessed anhedonia using changes in the use of a mechanical brush. Holstein heifers (n = 16) were trained to use a mechanical brush and then given the opportunity to individually brush for 10 min every 2 d. Time spent brushing (during a 10-min brush test) was collected before, during, and after regrouping (2-d interval) with the assumption that heifers would reduce their use of the brush during regrouping. Each heifer was individually regrouped into a new social group composed of 12 older and unfamiliar heifers and allowed access to the brush at 8 and 56 h after the onset of regrouping. Immediately after the last test, each heifer was brought back to her original pen and allowed to mingle with familiar pen-mates before being tested again 2 and 4 d later. When tested 8 h after regrouping, heifers reduced time spent brushing by 44 ± 27% (95% confidence interval: −96.18 to −41.8) compared with before regrouping; however, no differences were detected 56 h after regrouping. There was no relationship between the intensity of the decrease in brush use and any behaviors (number of agonistic interactions received, time heifers spent resting, or synchronization at the feed bunk) recorded for the 8 h immediately before testing (i.e., between 0 and 8 h and between 48 and 56 h after regrouping). These results indicate that regrouping induces anhedonia-like responses in dairy heifers on the day of regrouping. This routine procedure may thus induce negative mood in dairy heifers. This response was not related to behaviors typically collected to assess the negative effects of regrouping. Maintaining dairy cattle in stable social groups should be favored.

Conditioned place aversion of caustic paste and hot-iron disbudding in dairy calves

Cauterization by hot iron and application of caustic paste are 2 common methods of disbudding calves. In this study, we compared the affective experience of these 2 procedures on young dairy calves using conditioned place aversion. Male dairy calves (n = 14; 7 ± 2 d old) were disbudded by both thermal and chemical methods (1 horn bud at a time, 48 h apart). Calves received treatments in pens made visually distinct with either red squares or blue triangles on the walls. Calves were restricted to these treatment pens for 6 h following disbudding. For all treatments, calves received a sedative (xylazine, 0.2 mg/kg), local anesthetic (lidocaine, 5 mL), and analgesic (meloxicam, 0.5 mg/kg). Calves were then tested for conditioned place aversion at 48, 72, and 96 h after their last treatment. During tests, calves were placed in a neutral pen connected to both treatment pens where they had previously been disbudded. Time spent in each treatment pen was recorded until calves chose to lie down for 1 min (latency to lie down: 31.0 ± 8.6 min). During the first test (48 h after last disbudding), calves spent more time in the pen associated with hot-iron disbudding compared with what would be expected by chance (intercept: 73.5%, 95% CI: 56.5, 90.5) and fewer calves lay down in the caustic paste pen than in the hot-iron pen (3 vs. 10 lying events). No evidence of preference for the hot-iron pen was found in the following test sessions (72 and 96 h since last disbudding). These results suggest that calves initially remember caustic paste disbudding as a more negative experience than hot-iron disbudding, even with the use of sedation, local anesthesia, and analgesia.

Perspectives of western Canadian dairy farmers on the future of farming

Similar to the situation in many countries, the dairy industry in Canada is challenged by the need to adapt to changing societal demands. An industry-led initiative (Dairy Farmers of Canada's proAction Initative, known as proAction) was developed to respond to this challenge, providing mandatory national standards for on-farm practices. Farmers are more likely to follow such standards if they are aligned with their values and beliefs. The aim of this study was to better understand farmers' perspectives on the future of the Canadian dairy industry, with a focus on the role of mandatory policies such as those related to proAction. Seven focus groups were conducted, with discussions based on the principles of appreciative inquiry. Participants were each asked to write down key words that represent the "must-haves" on dairy farms in 20 yr from now. Although participants were encouraged to focus on aspects directly related to animal care, all answers were accepted. Key words were then used to facilitate a discussion and elicit ideas on how to achieve these must-haves. Particular focus was on the direction that participants believed policy should take to meet these goals. Explorative qualitative analysis was used for the written key words, and transcripts of the audio-recorded focus group discussions were analyzed using thematic analysis. Examples of farm-specific considerations that were raised as future must-haves of animal care on dairy farms included cow comfort, employee management, responsible health management, and use of advanced thechnologies. Participants agreed that objectives can only be achieved through collaboration among farmers and between farmers and researchers, and they regarded citizen education as a promising approach to align differing expectations of the public and farmers. Citizen trust in the dairy industry was considered a must-have, and participants believed that one of the benefits of mandatory policies for animal care is their potential to increase trust. These results may help guide the development of new animal care policies and increase understanding of the perceived legitimacy of new policies by dairy farmers.

Effect of cow-calf contact on cow motivation to reunite with their calf

Early cow-calf separation prevents much of cows’ natural maternal behaviour. Early separation is thought to prevent the development of a cow-calf bond. To assess this bond, we measured motivation of dairy cows to reunite with their calf. To vary the degree of bonding, some cows were allowed continued contact with their calf and others were separated from their calf soon after birth, following standard practice on most farms. Among cows allowed continued contact, some were able to suckle their calf and others were prevented from suckling (by covering the cow’s udder with an udder net). Cows were habituated to the weighted-gate apparatus before calving by daily training with the (un-weighted) gate. After calving, cow willingness to use the gate was assessed by determining if she would push open the gate to access to her own calf. Testing occurred once daily, with weight on the gate gradually increased. After passing through the gate, the dam’s calf-directed behaviour was recorded. Suckled cows pushed a greater maximum weight (45.8 ± 7.8 kg) than separated cows (21.6 ± 6.7 kg) and non-suckled cows (24.3 ± 4.5 kg), with no differences between separated and non-suckled cows. Once reunited, latency to make nose contact and duration of licking did not differ between treatments. We conclude that motivation for calf contact is greater for cows that are suckled.

Anticipatory behaviour in animals: A critical review

A number of studies have investigated anticipatory behaviour in animals as a measure of sensitivity to reward or as an expression of emotional state. A common feature of many studies is that they base inferences on seemingly arbitrary measures, for example, the frequency of behavioural transitions (ie number of times an animal switches between different behaviours). This paper critically reviews the literature and discusses various hypotheses for why specific behavioural responses occur in the anticipatory period between the signal and reward in conditioned animals. We argue that the specific behaviours shown may be the result of superstitious learning and thus highly variable, leaving behavioural transitions as the only response that can be scored consistently, and that sometimes these responses may relate more to frustration than to a positive emotional state. Finally, we propose new research approaches to avoid potential confounds and improve future studies on this topic.

Short communication: Motivation to walk affects gait attributes

Lameness is a major welfare problem in the dairy industry. Environmental factors, such as flooring surface, as well as cow-level factors, such as udder fill, can influence gait. The aim of the current study was to test whether motivation to walk affects gait attributes and whether this effect differs between lame and sound cows. We trained cows to walk down an alley for a food reward and assessed walking speed, stride length, head bob, and back arch of cows previously identified as either lame (n = 7) or sound (n = 10). Cows were assessed when they walked toward a food reward and toward no reward. Cows walked faster and had longer stride length and less variation in head bob when approaching the reward; these effects were similar in both sound and lame cows. We concluded that motivation to walk affects several gait attributes of dairy cows.

Behavioral changes associated with fever in transition dairy cows

Dairy cows are often diagnosed with fever without showing clinical symptoms of disease. The aim of this study was to investigate changes in feeding, social, and lying behaviors of cows with fever but without clinical disease, as compared with healthy cows. After parturition, dairy cows of mixed parities were housed in a dynamic group of 20. In the freestall pen, cows had access to 12 electronic feed bins, 2 electronic water bins, and 24 lying stalls. Feeding and social behaviors were recorded using the electronic feed bins, and lying behaviors were measured using electronic data loggers attached to the cow. Rectal body temperature was assessed on a daily basis, and fever defined as a body temperature >39.5°C. All cows were examined for metritis every third day after calving, and all other diseases (e.g., mastitis, ketosis) were diagnosed as per farm protocol. Cows with multiple days of fever (n = 8) and cows with 1 d of fever (n = 18) that were not diagnosed with a clinical disease were compared with a matched sample of healthy cows (i.e., cows that were not clinically ill and never had a fever recorded) of the same parity (categorized as primiparous vs. multiparous). Feeding, social, and lying behaviors were compared for the first 2 d of fever in cows with multiple days of fever, and the day of fever in cows with 1 d of fever. Cows of both fever groups spent less time feeding compared with controls (135 vs. 181 ± 7.6 min/d for multiple fever days, and 158 vs. 185 ± 9.7 min/d for 1 d of fever). Cows with 1 d of fever ate at a faster rate (109 vs. 91 ± 5 g/min) and had a lower number of replacements at the feed bunk (actor replacements: 9.7 vs. 14.6 ± 1.7 no./d; reactor replacements: 11.1 vs. 15.9 ± 1.6 no./d) compared with healthy controls. Overall, cows with fever showed behavioral changes such as decreased feeding time that are consistent with sickness responses described in other species.