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The history, implementation, and application of personality tests in livestock animals and their links to performance
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The author explores the viability of a comparative approach to personality research. A review of the diverse animal-personality literature suggests that (a) most research uses trait constructs, focuses on variation within (vs. across) species, and uses either behavioral codings or trait ratings; (b) ratings are generally reliable and show some validity (7 parameters that could influence reliability and 4 challenges to validation are discussed); and (c) some dimensions emerge across species, but summaries are hindered by a lack of standard descriptors. Arguments for and against cross-species comparisons are discussed, and research guidelines are suggested. Finally, a research agenda guided by evolutionary and ecological principles is proposed. It is concluded that animal studies provide unique opportunities to examine biological, genetic, and environmental bases of personality and to study personality change, personality–health links, and personality perception.
Large individual differences are commonly found in the behavior of octopuses, even in standardized situations. Octopus rubescens (n = 44) were tested in 3 situations (alerting, threat, and feeding) to quantify this variation. A factor analysis of resulting behaviors isolated 3 orthogonal dimensions of their variability, Activity, Reactivity, and Avoidance, which accounted for 45% of the variance. The similarity of these factors to dimensions of personality in humans and individual differences in animals suggests there may be commonalities in such variation across phyla.
Examines the use in the literature of the open-field test, especially with regard to the development of a standard form. The various procedures and their shortcomings are discussed, with particular reference to the seemingly inconsequential details which have been shown to modulate open-field performance per se. Dependent parameters are considered both with regard to their reliability and their validity for the measurement of such underlying constructs as emotionality. (92 ref)
There is growing evidence that animal personality is linked to a range of productivity traits in farm animals, including dairy cattle. To date, the methodology for assessing personality traits of dairy cattle is time consuming and often requires a test arena, which limits the opportunity for commercial farms to use personality traits of dairy cattle for individualized management. This study investigated whether personality traits of pastured dairy cattle, scored in short behavioral tests, are associated with daily behavioral patterns and milk production. Cows (n = 87) were exposed twice to each of 5 behavioral tests, where their responses to novel or putatively stressful situations were scored on an ordinal scale for investigative and reactive behavior toward a novel object and a novel human after exiting the milking parlor, response to restraint in a crush, avoidance distance from an approaching human in the paddock, and response to milking (step-kick behavior). Most behavior test scores were consistent over the 2 test repeats (using repeatability estimates, Mann-Whitney U test of difference between repeats, and Spearman rank correlation). Behavior test scores were subjected to a principal components analysis that revealed intertest relationships in 3 factors of correlated sets of test scores, interpreted as personality traits (fearful of humans, calm-investigative, and reactive to milking). Regression analyses determined how these traits were associated with daily grazing, ruminating, and lying behaviors, and milk production (after controlling for cow age, breed, lactation status, group, and climate variables). Cows that were more fearful of humans (high avoidance distance, reactive toward the novel human) had reduced lying time compared with cows that scored low on this trait. Cows that were more calm (during restraint) and investigative (toward the novel object) had greater grazing time, which likely contributed to their greater milk production compared with cows that scored low on this trait. Cows that were more reactive to milking produced less milk than cows that scored low on this trait. These results indicate that individual differences in daily behavior patterns and milk production of dairy cattle are associated with personality traits of cows, measured using several short behavioral tests. These methods may be useful for characterizing grazing dairy cattle on commercial farms, which could aid in understanding individual behavior patterns and provide opportunities for individualized management.
The primary objective of this study was to determine whether the level of concentrate allowance in an automated milking system (AMS) affects the feed intake, eating behavior, milking activity, and performance of lactating dairy cows. The secondary objective of this study was to describe how the response to concentrate allocation, specifically in feeding and milking behavior, varies with cow personality traits. Fifteen Holstein cows were used in a crossover design with two 28-d periods, each including 14 d of adaptation and 14 d of data collection. The cows were housed in a freestall pen with free-traffic access to the AMS. Treatments consisted of a basal partial mixed ration (PMR) common to both treatment groups, with a concentrate allowance (on dry matter basis) of (1) 3.0 kg/d in the AMS (L-AMS) or (2) 6.0 kg/d in the AMS (H-AMS). Between the 2 treatment periods, each cow was assessed for personality traits using a combined arena test consisting of exposure to a novel environment, novel object, and novel human. Principal component analysis of behaviors observed during the novel environment and object tests revealed 3 factors (interpreted as active, social, and alert-curious) that together explained 76% of the variance, whereas principal component analysis of the novel human test revealed 2 factors (interpreted as active-vocal and fearful of novel humans) that together explained 77% of the variance. When on the H-AMS treatment, PMR dry matter intake (DMI) was less (24.5 vs. 26.0 kg/d) and AMS concentrate delivery was greater (5.9 vs. 3.1 kg/d), as per design. Consequently, total DMI was greater on the H-AMS treatment (30.4 vs. 29.1 kg/d). When on the H-AMS treatment, cows who were more alert-curious consumed more PMR, whereas cows who were more fearful of the novel human were less likely to receive the maximum amount of AMS concentrate available, limiting their total DMI and increasing the day-to-day variability of that intake. Although this was a preliminary study, these data suggest an association between dairy cow personality traits and how cows respond to increased AMS concentrate allowance.
The use of an isolation box test (IBT) to characterize personality traits has been used in non-bovine species with success. We aimed to develop an IBT for dairy calves and determine if the behavioral responses to an IBT were associated with personality traits found from traditional tests (novel person, novel object, and a startle tests) and average daily gain (ADG; Kg/d) through weaning. Calf movement while in the IBT was measured via accelerometers attached to 5 locations on the exterior of the box. A total movement index (TMI) was calculated based on accelerometer readings during the IBT. We performed a principal component analysis on the traditional tests and identified 3 influential factors that we labeled as “fearful,” “bold,” and “active.” Calves were weighed biweekly to track liveweight ADG. Factor scores and ADG were regressed against TMI. A significant negative association was found between the TMI and the factor “active,” indicating the validity of IBT as a tool for assessing some personality traits of dairy calves. Furthermore, TMI had a positive association with ADG through the entire experimental period and thus has potential to help predict performance through weaning. IBT has potential to be used as a personality test in research scenarios. Further development is needed to produce an IBT that would be appropriate to measure animals' responses reliably in production settings. An automated test that can accommodate a wide range of ages and developing a computer learning model to interpret output from the IBT would be a possible option to do so.
Animal welfare is of general interest, and in the farming arena, efforts have increased to create optimal conditions for poultry production. Detailed and standardized studies on specific behavioral issues, such as fear, exploration, and social reinstatement behavior, are needed to support these initiatives. The variables mentioned can be directly queried from the animal in the open field to provide information on welfare-related behavioral traits, such as general fearfulness and balanced emotionality. Animal genetic resources help us get an insight into the possible diversity of behavioral responses. The majority of these responses can be identified as breed-specific and thus genetically correlated, providing a starting point for future breeding objectives. The behavioral responses of a chicken can be related to the breeding history of the population or to the experience gained during its lifetime. Both may go hand in hand to enable the animal to adapt to its environment, contributing to animal welfare.
Some research has described a relationship between personality and feeding behavior at weaning in Holstein dairy calves; our objective was to determine if personality traits, especially sociability, are associated with differences in feeding behavior and growth in Norwegian Red calves. Our secondary objective was to assess the interaction between personality traits and gradual weaning method (by age or by concentrate intake) on the behavior and growth of calves. Twenty-seven Norwegian Red calves were housed in 7 groups of 3 to 5 calves, with group composition based on birthdate to ensure that there were no more than 21 d between the youngest and oldest calves. Calves had access to an automated milk and concentrate feeder with ad libitum access to concentrates, water, hay, and silage. Calves were semi-randomly assigned to be either gradually weaned by age at d 56, or weaned by intake, where weaning was initiated based on reaching specific concentrate intake targets. We measured milk intake, concentrate intake, and the number of unrewarded visits to the automated feeder during each of 5 experimental periods: preweaning (12 L/d; 10–30 d of age), weaning (milk allowance gradually reduced by method until completely weaned), weaning week (3 d before weaning and the first 7 d of 0 L/d milk allowance), postweaning (20 d after complete milk removal), and the total experimental period (10–20 d postweaning). At 21 and 80 d of age, individual behavioral responses toward novelty and isolation (indicative of personality) were recorded in 3 personality tests: novel environment, novel object, and a social motivation test (time taken to return the group). At 83 d of age, a group novel object test was conducted. Principal component analysis revealed 3 factors interpreted as personality traits (playful/exploratory, vocal/active, interactive in group test) that together explained 56% of the variance. Calves that were more playful/exploratory consumed more milk per day preweaning and more concentrate per day over the experimental period. Calves that were more vocal/active (interpreted as a type of sociability trait where vocalizations and pacing serve to communicate with conspecifics when isolated from herd) had lower preweaning milk intakes and lower concentrate intakes over the experimental period. Calves that were more interactive in the group test (interpreted as a type of sociability trait when with other herd mates) had lower preweaning and weaning concentrate intakes. There was no interaction between personality traits and weaning method on feeding behavior or performance outcomes; however, calves that were weaned by intake (successfully reached all concentrate targets) had higher average daily gains postweaning, likely due to consuming more concentrate per day over the entire experiment, than calves who failed to reach all targets, or were weaned by age. We concluded that the sociability traits of Norwegian Red calves were related to individual differences in milk and concentrate intake. Although the relationship between personality and feeding behavior and growth did not depend on weaning method, gradual weaning based on individual concentrate intakes provides an opportunity for calves to wean at a pace that fits the needs of each individual calf.
An animal’s social position within a group can influence its ability to perform important behaviours like eating and resting, but little is known about how social position affects the ability to express what are arguably less important but still rewarding behaviors, such as grooming. We set out to assess if dominance measured at the feeder is associated with increased use of a mechanical brush. Over a 2-year period, 161 dry cows were enrolled in a dynamically changing group of 20 individuals with access to a mechanical brush. We determined dominance using agonistic behaviors at the feeder and retrospectively analyzed brush use for the 12 most, and 12 least dominant individuals during the week before calving. Cows that were more dominant at the feeder used the brush more, especially during peak feeding times. Agonistic interactions at the brush did not differ between dominants and subordinates and were not related to brushing duration. These findings indicate that social position, calculated using competition for feed, affects mechanical brush access such that subordinates use the brush less than dominant cows independent of competition or time of day.
Temperament is often defined as the behavioral expression of animals in response to human interaction. Cattle temperament can be evaluated using an association of chute score and exit velocity, with cattle then classified as adequate or excitable temperament. To assess the impacts of temperament on various beef systems, these evaluation criteria were associated with productive and reproductive parameters of Bos taurus and B. indicus-influenced cattle. Consistently across studies, excitable cattle had greater plasma cortisol compared to animals with adequate temperament. Studies also reported that excitable beef females have poorer reproductive performance compared to calmer cohorts, including reduced annual pregnancy rates, decreased calving rate, weaning rate, and kg of calf weaned/cow exposed to breeding. Acclimating B. indicus × B. taurus or B. taurus heifers to human handling improved behavioral expression of temperament and hastened puberty attainment. However, similar benefits were not observed when mature cows were acclimated to human handling. Collectively, temperament of beef females measured via behavioral responses upon human handling impacts their reproductive and productive responses independent of breed type, and should be considered for optimal beef cattle production.
Barren housing and high stocking densities may contribute to negative affective states in broiler chickens, reducing their welfare. We investigated the effects of environmental complexity and stocking density on broilers’ attention bias (measure of anxiety) and tonic immobility (measure of fear). In Experiment 1, individual birds were tested for attention bias (n = 60) and in Experiment 2, groups of three birds were tested (n = 144). Tonic immobility testing was performed on days 12 and 26 (n = 36) in Experiment 1, and on day 19 (n = 72) in Experiment 2. In Experiment 1, no differences were observed in the attention bias test. In Experiment 2, birds from high-complexity pens began feeding faster and more birds resumed feeding than from low-complexity pens following playback of an alarm call, suggesting that birds housed in the complex environment were less anx-ious. Furthermore, birds housed in high-density or high-complexity pens had shorter tonic immobility durations on day 12 compared to day 26 in Experiment 1. In Experiment 2, birds from high-density pens had shorter tonic immobility durations than birds housed in low-density pens, which is contrary to expectations. Our results suggest that birds at 3 weeks of age were less fearful under high stocking density conditions than low density conditions. In addition, results indicated that the complex environment improved welfare of broilers through reduced anxiety.
Human-animal interaction (HAI) research spans across many scientific fields and animal taxa. For livestock species, HAI research tends to focus on animals that are managed in close proximity with humans such as poultry, dairy cattle, and swine. Given the nature of rangeland cattle production, HAI research with beef cattle often occurs in and around the processing environment. This high arousal context may skew behavioral and physiological responses by the animals due to the potentially negative interaction. The aim of this review is to describe cattle production on rangelands, examine the considerations and limitations of current HAI research used to evaluate interaction quality or traits of rangeland cattle, identify contexts in which rangeland cattle interact with humans, and provide recommendations for improving future HAI research with rangeland cattle. Current research delineating individual differences in response to humans by beef cattle occur during routine husbandry and management on rangelands (pragmatic) and in a research context (experimental). Human-cattle interactions can be distinguished based on the quality and goal of the interaction into four broad categories: human presence, human approach, human contact, and restraint. Limitations of HAI research with rangeland cattle are identified and reconciled by recommendations for HAI research that can take place outside of the processing environment (i.e., while cattle are ruminating, resting or grazing on rangelands).
The aim of the study was to examine how early permanent separation, separation during the day only, or full-time access to the mother goat affected goat kids during social isolation with a sudden sound of a dog bark at two weeks and two months, and a novel arena test with a novel object at two months. Kids permanently separated reduced their vocalization earlier and had a higher heart rate before and after dog bark during isolation at two weeks, no effect was found on the daytime separated kids. Daytime separated kids bleated more at two weeks and decreased heart rate after dog barking at two months. Daytime separated kids showed the strongest fear reaction in the arena test, no effect was found on the permanently separated kids. Kids separated early vocalized more before novel object and showed more explorative behavior afterwards. Our study shows different responses in goat kids separated early permanent, daytime separated, or kept full-time with mother, which demonstrates the importance of if and how the mother is present, and the impact of using a wide variety of physiological and behavioral measures when evaluating stress in animal welfare research.
Individuals of many animal species are said to have a personality. It has been shown that some individuals are bolder than other individuals of the same species, or more sociable or more aggressive. In this paper, we analyse what it means to say that an animal has a personality. We clarify what an animal personality is, that is, its ontology, and how different personality concepts relate to each other, and we examine how personality traits are identified in biological practice. Our analysis shows that biologists often study specific personality traits, such as boldness, sociability or aggressiveness, rather than personalities in general. We claim that personality traits are best understood as dispositions and that they are operationally defined in terms of certain sets of behaviours, which are studied in specific experimental set-ups. Furthermore, we develop an integrative philosophical account that specifies and formalises three criteria for identifying personality traits, which are used in biological practice. For an individual animal to have a personality trait it must, first, behave differently than others (Individual Differences). Second, these behavioural differences must be stable over a certain time (Temporal Stability), and third, they must be consistent in different contexts (Contextual Consistency).
Previous research has shown that sensors monitoring lying behaviours and feeding can detect early signs of ill health in calves. There is evidence to suggest that monitoring change in a single behaviour might not be enough for disease prediction. In calves, multiple behaviours such as locomotor play, self-grooming, feeding and activity whilst lying are likely to be informative. However, these behaviours can occur rarely in the real world, which means simply counting behaviours based on the prediction of a classifier can lead to overestimation. Here, we equipped thirteen pre-weaned dairy calves with collar-mounted sensors and monitored their behaviour with video cameras. Behavioural observations were recorded and merged with sensor signals. Features were calculated for 1–10-s windows and an AdaBoost ensemble learning algorithm implemented to classify behaviours. Finally, we developed an adjusted count quantification algorithm to predict the prevalence of locomotor play behaviour on a test dataset with low true prevalence (0.27%). Our algorithm identified locomotor play (99.73% accuracy), self-grooming (98.18% accuracy), ruminating (94.47% accuracy), non-nutritive suckling (94.96% accuracy), nutritive suckling (96.44% accuracy), active lying (90.38% accuracy) and non-active lying (90.38% accuracy). Our results detail recommended sampling frequencies, feature selection and window size. The quantification estimates of locomotor play behaviour were highly correlated with the true prevalence (0.97; p < 0.001) with a total overestimation of 18.97%. This study is the first to implement machine learning approaches for multi-class behaviour identification as well as behaviour quantification in calves. This has potential to contribute towards new insights to evaluate the health and welfare in calves by use of wearable sensors.
Validation of precision dairy-monitoring technologies establishes technology behavioral-monitoring efficacy for research and commercial application. Technology metrics should be associated with behaviors of known physiological importance. The objective of this research project was to evaluate the Nedap SmartTag Neck (Nedap Livestock Management, Groenlo, the Netherlands) for dairy cow behavior measuring accuracy. The behaviors measured were eating, ruminating, and inactivity. Thirty-six lactating Holstein dairy cows were randomly selected from the University of Kentucky’s Coldstream Dairy Research Herd and fitted with a Nedap SmartTag Neck. Cows were observed by a single observer for a total of 4 h per cow, including 2 h after the morning milking (0800 h) and 2 h after the evening milking (2000 h), from May to December 2017. The observer recorded the time behaviors occurred using a synchronized watch (CASIO, CASIO America, Inc., Dover, NJ, USA). The hour, minute, and second of the day each behavior occurred were compared with corresponding technology measurements. Pearson correlation coefficients (r; CORR procedure; SAS Institute Inc., Cary, NC, USA), concordance correlation coefficients (CCC; epiR package; R Foundation for Statistical Computing, Vienna, Austria), and Bland–Altman plots (epiR package; R Foundation for Statistical Computing) were used to determine association between visual observations and technology-recorded behaviors. Visually recorded eating, ruminating, and inactive time were moderately to strongly correlated with technology data (CCC ≥ 0.88) and Bland–Altman plots showed no bias, indicating a high level of agreement. In conclusion, the Nedap SmartTag Neck accurately monitored eating, ruminating, and inactivity behaviors and is expected to be effective in monitoring these behaviors in lactating dairy cattle in research or commercial farm settings.
Legislative and market initiatives are requiring that gestating sows move from individual housing to group settings. Little information is known about coping of individual sows in these more socially complex environments and thus the impact of different behaviors on sow reproductive success was investigated. The movements of 70 sows during periods of reintroduction into large pen gestational housing following insemination was measured using Smartbow indoor positioning technology (Smartbow, Smartbow GmbH, Weibern, Austria) that tracked animal location and accelerations. Principle component analysis (PCA) was used to establish composite variables characterizing each animal’s behavioral response to social reintroduction and revealed the presence of two new variables accounting for over 60% of the variance in behaviors: one pertaining to total movement and the other pertaining to social dominance/rapid movements. Component scores of total movement predicted measures of reproductive success whereas social dominance/rapid movements predicted piglet birth weight. These findings suggest that differences in behavioral variables as measured by Smartbow’s automated, non-invasive, real time tracking system are correlated with productivity of sows housing in socially complex settings.
The feed bunk is a place of high competition for dairy goats, and high variability in feeding behaviour occurs; thus, it is necessary to understand why individuals respond differently when experiencing different feeding conditions. The objective of this study was to determine how personality traits affect competitive feeding behaviours of goats when feeding at a range of heights. Thirteen goats were provided one of three feeder heights (floor-, head-, and elevated-level) daily in a group pen under competitive feeding conditions and behaviours after feed delivery were recorded. Personality traits were assessed from behavioural responses toward two novelty and two fear tests; principal components analysis revealed four personality traits that were consistent over time: bold, fearful, exploratory and active-escape. These personality traits affected competitive behaviours, and often depended on feeder height. ‘Bold’ goats initiated more aggressive interactions, especially behind the floor-level feeder, and had greater feeding times; the opposite was observed in ‘fearful’ goats, which more often waited for access to the feeder. ‘Exploratory’ goats were less involved in aggressive interactions and spent less time feeding at the floor-level feeder, and more time feeding at the elevated-level feeder. While the findings are limited to a single group of goats, our pilot study suggests that personality traits may explain variability in feeding aggression and feeding time of goats under competitive feeding conditions, and that these differences may be promoted by feed offered at different heights. Further work is needed in larger groups of goats to understand why individuals appear to cope with competitive feeding practices in different ways.
Regrouping is associated with increased aggression, and disruption of time-budgets. Individuals vary in how well they cope with social stress. Our objective was to describe individual differences in agonistic behavior in dairy heifers after regrouping, and determine how time-budget and behavioral synchronization were affected by these coping strategies. A total of 30 heifers were individually regrouped at 5-months of age into stable groups of 12 unfamiliar animals. For 24 h, agonistic behaviors initiated and received by the regrouped heifer were continuously recorded, and standing, resting and feeding time and synchronization were sampled every 5 min. Scores of engagement in agonistic interactions and avoidance of interactions were calculated for each regrouped heifer. Linear mixed effects models were used to assess whether these two response types were related, and how variation in these responses related to activity and synchronization. Engaged heifers displayed lower avoidance and spent more time feeding. Avoidant heifers spent less time feeding and resting, and were less synchronized while feeding. We conclude that dairy heifers differ in social coping strategy when regrouped through different levels of engagement and avoidance, and that these differences affected their time-budget and behavioral synchronization.
Personality has been linked to individual variation in interest and performance in cog-nitive tasks. Nevertheless, this relationship is still poorly understood and has rarely been considered in animal cognition research. Here, we investigated the association between personality and interest, motivation and task performance in 13 sanctuary chimpanzees (Pan troglodytes) housed at Fundació Mona (Spain). Personality was assessed with a 12-item questionnaire based on Eysenck's Psychoticism-Extraversion-Neuroticism model completed by familiar keepers and researchers. Additionally, personality ratings were compared to behavioral observations conducted over an 11-year period. Experimental tasks consisted in several puzzle boxes that needed to be manipulated in order to obtain a food reward. Dependent variables included participation (as an indicator of interest), success and latency (as measures of performance), and losing contact with the task (as an indicator of motivation). As predicted, we obtained significant correlations between Eysenck's personality traits and observed behaviors, although some expected associations were absent. We then analyzed data using Generalized Linear Mixed Models, running a model for each dependent variable. In both sexes, lower Extraversion and lower Dominance were linked to a higher probability of success, but this effect was stronger in females. Furthermore, higher Neuropsychoticism predicted higher probability of success in females, but not in males. The probability of losing contact with the task was higher in young chimpanzees, and in those rated lower on Extraversion and higher on Dominance. Additionally, chimpanzees rated higher on Neuropsychoticism were also more likely to stop interacting with the task, but again this was more evident in females. Participation and latency were not linked to any personality trait. Our findings show that the PEN may be a good model to describe chimpanzee personality, and stress the importance of considering personality when interpreting the results of cognitive research in non-human primates. How to cite this article Padrell M, Riba D, Úbeda Y, Amici F, Llorente M. 2020. Personality, cognition and behavior in chimpanzees: a new approach based on Eysenck's model. PeerJ 8:e9707 http://doi.org/10.7717/peerj.9707
There is an increasing interest in using precision dairy technologies (PDT) to monitor real-time animal behavior and physiology in livestock systems around the world. Although PDT in adult cattle is extensively reviewed, PDT use for the management of preweaned dairy calves has not been reviewed. We systematically reviewed research on the use and application of precision technologies in calves. Accelerometers have the potential to be used to monitor lying behavior, step activity, and rumination, which are useful to detect changes in behavior that may be indicative of disease, responses to painful procedures, or positive welfare behaviors such as play. Automated calf feeding systems can control delivery of nutritional plans to individualize feeding and weaning of calves; changes in feeding behaviors (such as milk intake, drinking speed, and unrewarded visits) may also be used to identify early onset of disease. The PDT devices also measure physiological and physical attributes in dairy calves. For instance, temperature monitoring devices such as infrared thermography, ruminal boluses, and implanted microchips have been assessed in calves, but no herd management-based commercial system is available. Many other PDT are in development with potential to be used in dairy calf management, such as image and acoustic-based monitoring, real-time location, and use of enrichment items for monitoring positive emotional states. We conclude that PDT have great potential for application in dairy calf management, enabling precise behavioral and physiological monitoring, targeted feeding programs, and identification of calves with poor health or behavioral impairments. We strongly encourage further development and validation of commercially available technologies for on-farm application of the monitoring of dairy calf welfare, performance, and health.
The animal's reaction to human handling (i.e., temperament) is critical for work safety, productivity, and welfare. Subjective phenotyping methods have been traditionally used in beef cattle production. Even so, subjective scales rely on the evaluator's knowledge and interpretation of temperament, which may require substantial experience. Selection based on such subjective scores may not precisely change temperament preferences in cattle. The objectives of this study were to investigate the underlying genetic interrelationships among temperament measurements using genetic factor analytic modeling and validate a movement-based objective method (four-platform standing scale, FPSS) as a measure of temperament. Relationships among subjective methods of docility score (DS), temperament score (TS), 12 qualitative behavior assessment (QBA) attributes and objective FPSS including the standard deviation of total weight on FPSS over time (SSD) and coefficient of variation of SSD (CVSSD) were investigated using 1,528 calves at weaning age. An exploratory factor analysis (EFA) identified two latent variables account for TS and 12 QBA attributes, termed difficult and easy from their characteristics. Inclusion of DS in EFA was not a good fit because it was evaluated under restraint and other measures were not. A Bayesian confirmatory factor analysis inferred the difficult and easy scores discovered in EFA. This was followed by fitting a pedigree-based Bayesian multi-trait model to characterize the genetic interrelationships among difficult, easy, DS, SSD, and CVSSD. Estimates of heritability ranged from 0.18 to 0.4 with the posterior standard deviation averaging 0.06. The factors of difficult and easy exhibited a large negative genetic correlation of −0.92. Moderate genetic correlation was found between DS and difficult (0.36), easy (−0.31), SSD (0.42), and CVSSD (0.34) as well as FPSS with difficult (CVSSD: 0.35; SSD: 0.42) and easy (CVSSD: −0.35; SSD: −0.4). Correlation coefficients indicate selection could be performed with either and have similar outcomes. We contend that genetic factor analytic modeling provided a new approach to unravel the complexity of animal behaviors and FPSS-like measures could increase the efficiency of genetic selection by providing automatic, objective, and consistent phenotyping measures that could be an alternative of DS, which has been widely used in beef production.
Personality is often defined as the behaviour of individual animals that is consistent across contexts and over time. Personality traits may become unstable during stages of ontogeny from infancy to adulthood, especially during major periods of development such as around the time of sexual maturation. The personality of domesticated farm animals has links with productivity, health and welfare, but to our knowledge, no studies have investigated the development and stability of personality traits across developmental life stages in a mammalian farm animal species. Here, we describe the consistency of personality traits across ontogeny in dairy cattle from neonate to first lactation as an adult. The personality traits ‘bold’ and ‘exploratory’, as measured by behavioural responses to novelty, were highly consistent during the earlier (before and after weaning from milk) and later (after puberty to first lactation) rearing periods, but were not consistent across these rearing periods when puberty occurred. These findings indicate that personality changes in cattle around sexual maturation are probably owing to major physiological changes that are accelerated under typical management conditions at this time. This work contributes to the understanding of the ontogeny of behaviour in farm animals, especially how and why individuals differ in their behaviour.
Despite the growing interest in consistent individual differences in behaviour (animal personality), the influence of social context on different behavioural types remains poorly understood. The suite of correlated behaviours within and across contexts is called behavioural syndromes. Most personality studies have investigated consistent individual behavioural types and their consequences in a asocial context, however few studies have considered the influence of social context on individual behaviour. In addition, the evolutionary and ecological consequences of personality differences in social context remain unknown. In the present study, we confirm individual personality in Great tits ( Parus major ) using room exploration and neophobia tests. As a result of these two tests, repeatability and correlational structure of two personality traits were investigated. Additionally we assessed the extent to which personality influences dominance in a social feeding context.
Great tits remained consistent in their personality traits (exploration and neophobia). Individuals who explored a novel environment faster also approached a novel object faster, while those who spent more time exploring a novel environment were also slower to approach a novel object. In a social feeding context personality was linked to dominance: with proactive individuals being more likely to be dominant. Our result provides evidence of the importance of social context in a wild population of birds and may have fitness consequence, both for focal individuals and their conspecifics.
Accurate assessments of social behavior and dominance relationships in cattle can be time consuming. We investigated whether replacements at the feed bunk and water trough—one type of agonistic interaction—can be used to automatically assess dominance relationships. Our study set out to (1) validate a replacement detection algorithm using combined data from electronic feed and water bins, and (2) investigate the applicability of this algorithm to identify individual dominance scores and group-level social hierarchy in freestall-housed dairy cows. We used 4 groups of lactating cows kept in different group sizes (11 to 20 cows) located at 2 research facilities. In both facilities, feed and water were provided via automated feeding systems. A trained observer recorded all agonistic interactions in the pen over multiple days using video. Data from the electronic feed and water bins for the same days were analyzed using an algorithm to detect replacements (i.e., visits where a receiver cow was competitively replaced by an actor cow). Most agonistic interactions at the feed bunk were replacements. These replacements were associated with a brief interval between the time the receiver cow left the bin and the actor cow took her place; the optimal threshold to detect these replacements varied from 22 to 27 s between groups, independent of stocking density. The recall and precision of an algorithm based upon this threshold was high (on average >0.8), comparable to that of trained human observers. We improved data preparation by controlling for detection errors and included filtering to reduce false positives. This resulted in a >20% decrease in false positives and an increase in precision of 0.043. The dominance hierarchy based upon algorithm-detected replacements was similar to that based upon total agonistic interactions observed in the pen; the Spearman rank correlation coefficient between these hierarchies varied among the groups from 0.81 to 0.96. We conclude that data from electronic feed and water bins can accurately estimate agonistic behavior and dominance relationships among dairy cows.
As part of the European Conference on Behavioral Biology 2018, we organized a symposium entitled, “Animal personality: providing new insights into behavior?” The aims of this symposium were to address current research in the personality field, spanning both behavioral ecology and psychology, to highlight the future directions for this research, and to consider whether differential approaches to studying behavior contribute something new to the understanding of animal behavior. In this paper, we discuss the study of endocrinology and ontogeny in understanding how behavioral variation is generated and maintained, despite selection pressures assumed to reduce this variation. We consider the potential mechanisms that could link certain traits to fitness outcomes through longevity and cognition. We also address the role of individual differences in stress coping, mortality, and health risk, and how the study of these relationships could be applied to improve animal welfare. From the insights provided by these topics, we assert that studying individual differences through the lens of personality has provided new directions in behavioral research, and we encourage further research in these directions, across this interdisciplinary field.
The assessment of individual traits requires that tests are reliable (i.e. consistency over time) and externally valid, meaning that they predict future responses in similar contexts (i.e. convergent validity) but do not predict responses to unrelated situations (i.e. discriminant validity). The aim of this study was to determine if dairy calf personality traits (Fearfulness, Sociability and Pessimism), derived from behaviours expressed in standardized tests, predict individuals’ responses in related situations. The rst experiment tested if the trait ‘Sociability’ was related to the expression of social behaviour in the home-pen, with calves assigned individual proximity scores (based on proximity to other calves) while they were in their home-pen at approximately 113 and 118 d of age. The second experiment aimed at exploring whether traits ‘Fearfulness’ and ‘Pessimism’ were related to the calves’ emotional response
to transportation. All calves were subjected to two 10-min transportation challenges done on two consecutive days. Emotional response was assessed using the maximum eye temperature (measured using infrared thermography) and the number of vocalizations emitted. Social proximity scores (Experiment 1), vocalizations emitted and maximum eye temperature after loading (Experiment 2) were consistent over time. In addition, the results showed good convergent validity with calves scoring higher in Sociability also having higher proximity scores in the home-pen, and animals scoring higher in Fearfulness and Pessimism showing a more intense emotional response to transportation. The results also showed good discriminant validity, as neither Fearfulness nor Pessimism were associated with the expression of social behaviours (Experiment 1) and Sociability was not associated with the animal’s emotional response to transportation (Experiment 2). We conclude that the methodology used to measure personality traits shows good reliability and external validity.
Dairy precision technologies helps producers monitor individual animals. Reticulorumen temperature boluses are a way to monitor core body temperature; however, factors such as water intake affects reticulorumen temperature. This research determined the effect of natural water intake and a controlled water drench on reticulorumen temperature (RT) in dairy cattle. In observational study part 1, tie- stall cows (n = 4) with RT transponders were observed for natural water intake (recorded by in line water meters) for 48 h. In experiment part 2, a randomized Latin square design with cows (n = 12) restricted on feed for 4 h, were drenched daily with a water quantity of 6.7 L, 11.4 L or 22.7 L, and at controlled water temperature of 1.7 °C, 7.2 °C, 15.5 °C, or 29.4 °C. Descriptively, observational study 1 had (Mean ± SD 0.27 ± 0.31 L ingested per drinking event (n = 84) and RT decline from baseline was 2.29 ± 1.82 °C. For the experiment, a 48-h specific rolling baseline temperature range (BTR) was calculated for each cow prior to the experiment to determine time required for RT to reach BTR, and time to return to BTR. In part 2 of the experiment, as water quantity increased, RT had a greater maximum degree drop from baseline. Water temperature and water quantity interaction influenced time required for BTR to reestablish. The coldest water temperature at the highest drench quantity affected time for BTR to reestablish the longest (103 min). Results from this study suggest that an algorithm could be designed to predict water intake events for producers using reticulorumen temperature.
Measuring and understanding personality in animals is a rising scientific field. Much research has been conducted to assess distinctive individual differences in behavior in a large number of species in the past few decades, and increasing numbers of studies include farm animals. Nevertheless, the terminology and definitions used in this broad scientific field are often confusing because different concepts and methods are used to explain often synonymously applied terms, such as personality, temperament and coping style. In the present review we give a comprehensive overview of the concepts and terms currently used in animal personality research and critically reveal how they are defined and what they measure. First, we shortly introduce concepts describing human personality and how these concepts are used to explain animal personality. Second, we present which concepts, methods and measures are applied in farm animal personality research and show that the terminology used seems to be somehow species-related. Finally, we discuss some findings on the possible impact of personality on the welfare of farm animals. The assessment of personality in farm animals is of growing scientific and practical interest. Differences in theoretical frameworks and methodological approaches may also entail the diverse use of the different concepts between basic and applied research approaches. We conclude that more consistency is needed in using different theoretical concepts, terms and measures, especially in farm animal personality research. The terms coping style and temperament, which are used in different ways, should not be examined as independent concepts, but rather should be considered as different aspects of the whole personality concept. Farm animal personality should be increasingly considered for the improvement of animal housing, management, breeding and welfare.
Performance varies considerably at weaning, perhaps in part because it is associated with the personality traits of the animals. Our objective was to identify calf personality traits using standardized tests and determine whether these were associated with measures of feeding behavior and performance. Fifty-six dairy calves were housed in 7 groups of 8 calves each with access to an automated milk feeder and ad libitum access to water, starter, and hay. We measured starter DMI and the number of unrewarded visits to the automated milk feeder during each of 4 periods: prestep (full milk allowance; 7-41 d of age), step (milk allowance reduced to 50%; 42-50 d of age), weaning (51-54 d of age), and postweaning (55-68 d of age). At 27 and 76 d of age, each calf was subjected to 3 novelty tests: novel environment (30 min), human approach (10 min with an unknown stationary human), and novel object (15 min with a black 140-L bucket). During each of the tests, 7 behaviors were scored: latency to touch and duration of touching the human or object, duration of attentive behavior toward the human or object, number of vocalizations, number of quadrants crossed as a measure of activity, and duration of inactivity, exploration, and playing. Data were averaged across ages and then across tests. Principal component analysis revealed 3 factors (interactive, exploratory-active, and vocal-inactive) that together explained 73% of the variance. Calves that were more exploratory-active began to consume starter at an earlier age and showed greater starter dry matter intake during all experimental periods and greater overall average daily gain. Calves that were more interactive and vocal-inactive had more unrewarded visits to the milk feeder during initial milk reduction. We conclude that personality traits are associated with feeding behavior and performance around weaning.
As the number of gestating sows reared in group housing increases, a better understanding of behavioral traits needed to negotiate these more complex social interactions promises to increase animal welfare and productivity. However, little is known about different behavioral strategies or coping styles in sows, and even less is understood about their ontogeny. To study the development of coping styles in adult gestating sows, 36 sows from the same sire line and same commercial maternal genetics were followed from birth through their second parity. Each animal was observed in a battery of stress-related behavioral tests at 5 weeks, and 3 months of age as well as 24 h postpartum as a parity 1 sow, and during introduction to subsequent gestation period in group housing. The tests at different ages included response to handling, open field exploration, human interaction, litter handling and social interactions with conspecifics. Many of the observed behaviors were correlated during the same period of the animal’s life and provided the motivation for a principal component analysis by age. Using principal component analysis, multiple traits were determined at each age point; at 5 weeks old: active, non-exploratory and cautious explained 82.5% of the variance; at 3 months of age: active, non-exploratory and low fear of humans explained 87.7% of the variance; and as primiparous sows: active, aggressive/dominant and submissive explained 82.0% of the variance. Several individual juvenile behaviors were associated with adult behavioral traits. For instance, the response to handling at 5 weeks was significantly predictive ( β =0.4; P <0.05) of the aggressive/dominant trait of parity 1 sows. Taken together results presented here suggest that early behavioral responses of prepuberal gilts during specific instances of elevated environmental or social stress can predict future behavioral response as gestating sows.
Since the introduction of the backtest for the early detection of coping strategies in piglets by Hessing in the 1990s, this behavioural test has been intensively investigated with ambiguous results. One possible explanation for this lack of consistency might be the different classification methods used in many studies, so the first aim of this research was to investigate the inter-situational consistency of backtest behaviour in a set of 120 piglets. Through a correlation analysis, we related backtest behaviour with behaviours in other test situations (mixing/dominance; group testing: human approach test (HAT), novel object test (NOT), open door test (ODT); and individual testing: open field test (OFT)). Second, in a larger number of piglets (n = 3555), we investigated four different classification methods that use different parameters (latency, duration, and frequency) and different test repetitions (1, 2, 3, and 4). We then tested the effect of classifying the animals according to each method and analysing their distribution across categories and the variance in the behavioural data using the 120-piglet dataset (category analysis). Finally, we validated the results of the category analysis with the results of the correlation analysis. The correlation analysis revealed weak (dominance: rS < 0.18) to moderately strong (group and individual testing: rS < 0.38) relationships between the backtest behaviour and the behaviour during the other tests, and some correlations reached significance, especially with the HAT and the OFT (locomotion, exploration and object contact). The investigation of different classification
Many people in several countries worldwide, particularly in Asia, India, and South America, are getting more financial possibilities to buy animal protein. This fact, combined with the changing diets of these people in those countries, will result in an increase of the worldwide demand for animal products (meat, eggs, and milk) of 70% by 2050. Consequently, the number of livestock is increasing, while at the same time, the number of farmers is decreasing. This results in much bigger herds per farmer. It has become impossible for farmers to follow all of their animals in a reliable way in such big groups. At the same time, several issues must be solved now in the livestock sector, such as monitoring animal health and welfare, reducing the environmental impact, and assuring the productivity of the process. Precision livestock farming (PLF) aims to offer a real-time monitoring and managing system for farmers. This is fundamentally different from other approaches that tried to monitor the animal welfare by human experts scoring animal-based indicators. These methods do not improve the life of the animal under consideration. It is nice to detect a problem after an animal has arrived at the slaughterhouse, but it is much better to detect a problem while the animal is being reared and to take immediate management action. The idea of PLF is to provide a real-time warning when something goes wrong so that immediate action can be taken by the farmer to solve the problem. To bring PLF technology further into field application, increased development and testing of PLF technologies is required in real farms to implement reliable solutions. To further develop and introduce such supporting management PLF systems, some basic principles must be respected.
The backtest response of a pig gives an indication of its coping style, that is, its preferred strategy to cope with stressful situations, which may in turn be related to production traits. The objective of this study was therefore to estimate the heritability of the backtest response and estimate genetic correlations with production traits (birth weight, growth, fat depth and loin depth). The backtest was performed by placing the piglet on its back for 60 s and the number of struggles (NrS) and vocalizations (NrV), and the latency to struggle and vocalize (LV) was recorded. In total, 992 piglets were subjected to the backtest. Heritability estimates for backtest traits were statistically moderate (although high for behavioral traits), with LV having the highest heritability estimate (0.56±0.10, P
Animals with excitable temperaments often have decreased gains that have been associated with decreased intake and efficiency. Different temperament measures probably measure different specific underlying traits. Commonly used temperament measures include both objective and subjective measures. Subjective measures present potential difficulties for making across-study comparisons and thus for generalizing quantitative relationships. One objective of this experiment was to evaluate 2 related, but different, measures associated with temperament, where 1 measure is a new, objective measurement based on the common subjective chute score measures. Also, there is reason to believe that RDP requirements of animals may vary with temperament. To examine the relationships between temperament measures and nutrient use, 192 crossbred steers were used in a 58-d randomized complete block design experiment. Temperament treatments (assigned prior to d 1) were chute exit velocity (EV; slow vs. fast) and objective chute score (WSD; low vs. high), a novel temperament measure that was the SD of weights collected at 5 Hz for 10 s while an animal was restrained in a chute with its head caught. Both were measured on d -8, 1, 2, 16, 30, 56, and 58, where d 1 was the day that animals were allotted to treatment groups and began receiving experimental diets. Steers were fed a diet with 1 of 3 RDP levels (75%, 105%, and 120% of RDP requirements). There were no main effects or interactions with RDP ( ≥ 0.12); thus, it was removed from the statistical model for subsequent analyses. There were no interactions between EV and WSD ( ≥ 0.11). Slow EV animals had greater ADG ( = 0.02) and DMI ( ≤ 0.09) than fast EV animals, but there was no effect of EV on G:F ( > 0.14). For d 0 to 58, high WSD animals had greater DMI ( ≤ 0.09) than low WSD animals but no difference in ADG ( = 0.23), whereas low WSD animals tended to have increased G:F ( = 0.11). Results of this study give additional confirmation that EV is associated with DMI and growth and provide evidence that a novel measure of behavior, WSD, is also related to growth, independently of EV. Because WSD and EV appear to measure different underlying behavioral traits, use of both measures may improve our ability to discriminate among temperament categories for growing cattle.
This chapter provides an overview of the current behavioral and cognitive aspects of emotions in animals and explores the impacts of emotional experiences on the animal’s adaptation to its current challenging circumstances. There is evidence that animal welfare results from the animal’s perception of its environment and its background. The chapter is structured in four complementary sections. The first one addresses the nature of emotions that the animals can feel which is validated from commonalties in physiological and behavioral responses to dangers across and within species. The second section presents advanced features of the relationships between cognition and emotions originally studied in humans, which are now developed in animals to better access their affective states. The third section is devoted to the relevance of the personality concept, as resulting from both genetics and developmental experience, for assessing animal individuality in emotional behaviors and stress. The last section explores some approaches that can alleviate fear and induce positive affective states, with the potential to mitigate detrimental stress-induced effects on the welfare and health status by eliciting positive emotions in animals.
While relatively little is known about the psychology of domestic pigs, what is known suggests that pigs are cognitively complex and share many traits with animals whom we consider intelligent. This paper reviews the scientific evidence for cognitive complexity in domestic pigs and, when appropriate, compares this literature with similar findings in other animals, focusing on some of the more compelling and cutting-edge research results. The goals of this paper are to: 1) frame pig cognition and psychology in a basic comparative context independent of the livestock production and management setting; and 2) identify areas of research with pigs that are particularly compelling and in need of further investigation. We summarize and discuss several areas of comparative psychology, including nonsocial and social cognition, self-awareness, emotion, and personality. We conclude that there are several areas of research in which the findings are suggestive of complex psychology in pigs. We conclude by calling for more noninvasive cognitive and behavioral research with domestic pigs in non-laboratory settings that allow them to express their natural abilities.
The objective of this study was to evaluate the effects of temperament classification (assessed using an arena test) on health and productivity of Hu ram lambs. In experiment one, eight ram lambs classified as calm and eight classified as nervous (selected from 100 ram lambs) were fed individually for 60-days to compare food intake, food digestibility, weight gain, and biochemical indices of health. In experiment two, nine ram lambs classified as calm and nine classified as nervous (selected from 150 ram lambs) were fed in a group and slaughter traits, meat quality, and muscle histology were compared. Calm lambs had higher dry matter digestibility, lower serum TNF-α, higher total antioxidant capacity, higher total superoxide dismutase activity, higher dressing percentage, higher cross-sectional area of loin, higher myofibre density, lower ultimate pH of the meat, and higher meat redness, than nervous lambs. Selection for calm temperament could be beneficial to health, slaughter, and carcass traits in Hu ram lambs.
The behavioural reactivity of two divergently selected lines of South African Merino sheep for an increased (HL: N = 1187) and reduced (LL: N = 285) number of lambs weaned per ewe mated was investigated using a docility test and a 'scale' test. The objective of this study was to determine whether these two lines, which differed significantly in terms of reproduction performance, would also react differently when exposed to novel and challenging situations. In the first test, an individual animal was moved to the test pen by an experienced handler then an unfamiliar or familiar human entered the test pen and tried to encourage the animal to move into a marked area for 3 min. The test was terminated if the animal could not be moved within 3 min, came out of the marked area or if the animal could be contained in the marked area for 30 s (successful test). The latency of the animal to enter and time contained in the square area was recorded as well as whether the animal was bleating or urinating/defecating during the test. No difference was found between production lines and handler in terms of the success of the test and latency to enter (P > 0.05). LL sheep were however contained for longer and bleated more than HL sheep (P < 0.05). Sex differences were also observed, with ewes being more difficult to successfully contain and bleating more than rams, especially when exposed to an unfamiliar human (P < 0.05). They also tended to urinate/defecate more than rams (P < 0.05). In the second test, behaviour response of animals was recorded using a 5-points score system (1 = calm; 5 = wild) while spending 30 s on a scale. We also recorded whether animals were bleating during the test. While there was no difference in average scores between selection lines (P> 0.05), inter-observer variability was observed (P < 0.05). Ewes were also observed to bleat more than rams (P < 0.05). Further research is needed to determine whether these and other behavioural tests are related to traits of economic importance in sheep.
The application of accelerometer sensors for automated animal behaviour monitoring is becoming increasingly common. Despite the rapid growth of research in this area, there is little consensus on the most appropriate method of data summation and analysis. The objective of this current study was to explore feature creation and machine learning (ML) algorithm options to provide the most accurate behavioural classification from an ear-borne accelerometer in extensively grazed sheep. Nineteen derived movement features, three epochs (5, 10 and 30 s) and four ML-algorithms (Classification and Regression Trees (CART), Linear Kernel Support-Vector Machines (SVM), Linear Discriminant Analysis (LDA) and Quadratic Discriminant Analysis (QDA)) were assessed. Behaviour classification was also evaluated using three different ethograms, including detection of (i) grazing, lying, standing, walking; (ii) active and inactive behaviour; and (iii) body posture. Detection of the four mutually-exclusive behaviours (grazing, lying, standing and walking) was most accurately performed using a 10 s epoch by an SVM (76.9%). Activity was most accurately detected using a 30 s epoch by a CART (98.1%). LDA and a 30 s epoch was superior for detecting posture (90.6%). Differentiation relied on identification of disparities between behaviours rather than pattern recognition within a behaviour. The choice of epoch and ML algorithm will be dependent on the application purpose, with different combinations of each more accurate across the different ethograms. This study provides a crucial foundation for development of algorithms which can identify multiple behaviours in pasture-based sheep. This knowledge could be applied across a number of contexts, particularly at times of change in physiological or mental state e.g. during parturition or stress-inducing husbandry procedures.
Social personality can be key factor in evolution because of intraindividual consistency, heritable basis, and linkage with fitness. The aim of this study was to identify the existence of sheep personality profiles based on the use of social strategies and its associations on morphological, cognitive, and reproductive success. Fifty adult ewes, housed indoor, were studied in terms of social and maintenance behavior, stress response, morphological variables, and productive performance. The cognitive abilities of the ewes were also analyzed. A factor analysis was used to summarize the data of 7 social behavioral variables. Agonistic and nonagonistic behaviors were grouped in classes. The factors were extracted using principal components. A hierarchical cluster analysis was performed to identify clusters or profiles. The results demonstrated the existence of 4 personalities profiles (avoider, affiliative, aggressive, and pragmatic), determined by social behavior and the index of success. The study addresses the multidimensionality of personality, showing that sheep personality comprises several social and nonsocial dimensions. The data confirm that the use of social strategies and the index of success are a useful tool to predict individual differences or personalities in a flock.
Temperament of cattle impacts efficiency of production systems, including animal well-being. In being heritable, temperament can be augmented through selection. Current methods to evaluate temperament in a production setting include chute score (CS), exit score (ES), and exit velocity (EV), which some producers may find cumbersome to navigate. Even those who utilize these methods may not do so efficiently if initial evaluations are not strong indicators of future temperament. The objectives of this study were to determine whether temperament in animals change under repeated and routine handling experiences, and to estimate the relationships among CS, ES, and EV. Over three consecutive years, a factorial design of two measurement protocols [frequent (F), infrequent (IN)], and three recording periods was used. The F measurements were collected over three consecutive days, and IN measurements only on day one within a recording period. Each year, twenty commercial Bos taurus heifers were randomly assigned to each protocol. Once heifers were weighed, and their heads caught in the squeeze chute, a CS was assigned from 1 (docile) to 6 (aggressive) by three observers. Exit velocity was obtained on release from the chute, and an ES given from 1 (docile) to 5 (aggressive) by the same observers. For all heifers, protocol, event, and their interaction, were compared on day one. For F heifers, event and day within event were instead fitted. For both models, body weight was included as a covariate, with sire and year fitted as random effects. Pearson correlations among measurements were calculated on day one of each recording period separately, and for days combined. Chute score decreased across events and days in F (P < 0.09). Heifers with higher CS on day one had the largest reduction in score. Exit scores and EV changed less over time (P > 0.13) and were highly correlated (r = 0.81), characterizing the same behavior. Correlations between CS and ES (r = 0.14) or EV (r = 0.08) during the first recording period were close to zero (P > 0.05), but increased as CS decreased. Chute score therefore may be more indicative of acclimation to a novel environment than ES or EV. Both CS and ES appear to offer an easy and inexpensive way to quantify temperament in cattle. Heifers became calmer with repeated gentle handling. Producers may avoid unnecessarily culling cattle based strictly on initial response to novel stimuli by allowing acclimation to handling before assessing docility.
Identification of the associations of cow feeding behavior with productivity is important for supporting recommendations of strategies that optimize milk yield and composition. The objective of this study was to identify associations between measures of feeding behavior and milk production using data collated from studies of the feeding behavior of lactating dairy cows. A database containing behavior and production data for 132 dairy cow-week observations (mean of 7 d of consecutive data per cow) was assembled from 5 studies. Cows averaged (mean ± standard deviation) 1.8 ± 0.9 lactations, 108.4 ± 42.7 d in milk, and 654.6 ± 71.4 kg of body weight during each observation week. Production data included dry matter intake (27.0 ± 3.1 kg/d), milk yield (43.0 ± 7.0 kg/d), milk fat content (3.60 ± 0.49%), and milk protein content (3.05 ± 0.25%). Behavioral data included feeding time (230.4 ± 35.5 min/d), feeding rate (0.13 ± 0.03 kg/min), meal frequency (9.0 ± 2.0 meals/d), meal size (3.2 ± 0.9 kg/meal), daily mealtime (279.6 ± 51.7 min/d), and rumination time (516.0 ± 90.7 min/d). Data were analyzed in multivariable mixed-effect regression models to identify which behavioral variables, when accounting for other cow-level factors (days in milk, parity, and body weight) and dietary characteristics (forage level, nutrient content, and particle distribution), were associated with measures of production. Dry matter intake was associated with feeding time (+0.02 kg/min) and tended to be associated with rumination time (+0.003 kg/min) and meal frequency (+0.2 kg/meal). Similarly, milk yield was associated with feeding time (+0.03 kg/min) and rumination time (+0.02 kg/min), and tended to be associated with meal frequency (+0.3 kg/meal). Milk fat yield was associated with meal frequency (+0.02 kg/meal). Overall, our results suggest that milk yield and component production may be improved in situations where cows are able to increase their time spent feeding, in more frequent meals, and time spent ruminating.
Measures of temperament have been previously related to gain and intake in beef cattle. Intake effects may be partially mediated through social interactions in that some temperament measures may directly relate to social dominance behavior. To examine the relationships between temperament, growth, and social dominance behavior, thirty-two crossbred steers were used in a 56-d randomized complete block design experiment with a 2. ×. 2 factorial treatment structure. Temperament treatments (assigned on d -7) were chute exit velocity (EV; slow vs. fast) and objective chute score (OCS; low vs. high), a novel temperament measure, defined as the coefficient of variation of recorded weight values collected at five Hz for 10. s while an animal's head was restrained in a chute. Electronic ear tags with accelerometers were used to continuously measure animal activity. Social dominance behaviors were quantified using video records of 2. h intervals directly following feeding for d 1-13. Dominance was calculated as average dominance index and David's score. Jugular blood samples were collected to analyze antibody response to leptospirosis vaccines. There were no EV by OCS interactions (P. ≥. 0.23) for average daily gain (ADG) or antibody titers. High OCS steers gained 0.26. kg/d more than low OCS steers (P. <. 0.01) and slow EV steers gained 0.12. kg/d more than fast EV steers (P = 0.02). Slow EV animals had an increased antibody response compared with fast EV animals (P = 0.05). Ranking in the dominance hierarchy was influenced by an EV. ×. OCS interaction (P. <. 0.02), but there was not a linear relationship between dominance ranking and ADG. Low OCS steers tended to have higher daily activity counts than high OCS steers (P = 0.11), and fast EV steers had higher (P = 0.08) activity counts than slow EV steers. In conclusion, our two temperament-related measures, EV and OCS, were independently related to differences in ADG. Although dominance ranking was significantly related to the interaction of these two temperament measures, it was not linearly related to ADG. Alternatively, differences in accelerometer-based activity counts among temperament groups did correspond with trends in growth responses.
Though the study of animal personality has experienced explosive growth in the last 20 years, its history can be traced to the early days of comparative psychology. Early descriptions of nonhuman animals as sociable or fearful and the like have been progressively replaced across the years with systematic coding of behavioral patterns across multiple dimensions of temperament, in a fashion (and with results) similar to the way the topic is studied in humans. This chapter will explore the researchers, laboratories, and methodologies of animal personality research as it evolved from a methodologically impermeable curiosity to an increasingly important determinant of individual and species variability in behavior.
Breeding of cattle with docile temperament can simplify routine practices and enhance welfare of cattle in common production systems. The aim of the study was to compare and validate some aspects of assessment methods for temperament traits in cattle for their potential use in breeding programmes. Calves of different beef and dairy cattle breeds were video-recorded during a 2 min tethering (n = 160) and a 2 min crush test (n = 185) at the age of 38 ± 25 days. Subsequently, two observers blinded to the identity of records each analysed the video clips three times with the software Interact® in intervals of 1–2 days between viewings. Frequency and duration of behaviour patterns such as head movement, tail flicking or defecation were recorded. In addition, each behaviour pattern was assessed on a 10 cm visual analogue scale (VAS) and in the end of each observation an overall behaviour score on a numerical scale from 1-5 and on a VAS was assigned to each animal. Using variance components from mixed model analysis, results revealed that both inter- and intra-observer reliability (OR) were similar or superior for the majority of behaviour patterns when assessed with the VAS compared to the more time-consuming assessment of exact frequencies and durations (e.g. Intra-OR ‘tail flicking’: Observer I: rVAS = 0.83 and rFreq = 0.26; Observer II: rVAS = 0.91, rFreq = 0.37 and rDur = 0.87 for the tethering test; Inter-OR ‘body movement’: rVAS = 0.81 and rFreq = 0.33 for the crush test). The overall behaviour score showed a high intra-observer reliability when assessed with the VAS as well as with the numerical scale (Observer I: rVAS = 0.97 and rNum = 0.77; Observer II: rVAS = 0.82 and rNum = 0.84 for the crush test). However, not all traits, and particularly including those assessing rarely occurring behaviour patterns, proved to be appropriate for recording with a VAS. In conclusion, a VAS that is based on carefully selected features can be considered a reliable and practical method for temperament assessment in cattle.
Boldness, the willingness of individuals to engage in risky behaviour, is one of the most studied personality traits. It has been measured using a variety of tests; however, measuring a behaviour using different assays may lead to a jingle fallacy. The few studies that have attempted to determine whether these different assays are comparable have produced mixed results. A lack of repeatability between boldness measures under standardized and natural conditions may be the source of this variation. Here, we tested whether risk-taking behaviour of free-living African striped mice, Rhabdomys pumilio, measured in a laboratory using open field tests is comparable with measures of risk-taking behaviour from startle tests. These measures were then compared with measures of risk-taking behaviour obtained from equivalent open field and startle tests performed on the same individuals under natural conditions. During open field tests, we assessed the time an individual spent away from the wall of the arena (in the laboratory) or from its nest (in nature). During startle tests, we measured the latency to re-emerge from either a protective box (in the laboratory) or a nest (under natural conditions) after an individual was scared away. Our results showed that risk-taking behaviour measured using the open field and the startle tests were repeatable within the same context (tested twice per assay) and across contexts (laboratory, nature). However, open field measures of risk-taking behaviour were not correlated with startle measures, supporting the idea that the two tests are assaying different personality traits. The variations in the outcome observed in the two assays probably resulted from the presentation of threatening stimuli in the startle test. We propose that, at least in striped mice, the startle test is more suitable for measuring anxiety than boldness.
Exaggerated fear-reactions are associated with injurious flying, smothering, feather pecking and other events that compromise animal welfare in laying hens. The aim of this study was to test the hypothesis that chicks with access to litter during the first five weeks of life would be less fearful as adult hens compared to birds reared without access to litter. The hypothesis was tested in a national on-farm study in commercial aviary flocks in Norway. Five rearing farmers divided the pullets into two groups within their rearing houses. While the chicks were enclosed inside the aviary rows during the first five weeks of life, paper substrate where food and other particles could accumulate, covered the wire mesh floor in the treatment group, whereas the control group was reared on bare wire mesh. At 30 weeks of age, 23 aviary flocks (11 control flocks reared without paper and 12 treatment flocks reared with paper) were visited. During the visit, the fearfulness of the adult birds was tested in a stationary person test and a novel object test. The data was analysed by ANOVA or logistic regression as appropriate. The access to litter during rearing did not influence the number of birds that approached within 25 cm of the stationary person (p = 0.51). All flocks, regardless of rearing treatment, had birds which came within 2 m of the stationary person. The latency to approach within 2 m of the stationary person tended to be influenced by provision of environmental enrichment as adults (p = 0.08) and by the interaction between treatment × rearing farm (p = 0.08). The number of birds that approached within 2 m of the stationary person was influenced by the interaction between treatment during rearing and provision of enrichment as adults (p = 0.03), however, the post hoc test showed no pairwise differences. All flocks, regardless of rearing treatment, had birds that approached the novel object. The access to litter during rearing did not influence the birds’ latency to approach the novel object. The number of birds approaching the novel object was affected by the interaction between access to substrate during rearing and provision of environmental enrichment as adults (p = 0.05). The results indicate that both adding paper substrate to chicks from the first day of life and environmental enrichment as adults, reduce fearfulness in laying hens.