Inconsistency in dairy calves’ responses to tests of fearfulness

Early-life contact with non-maternal adult cows and a pasture-based rearing environment influence behavioural responses of dairy heifers to novelty

The complexity experienced in early life can affect trait development of individuals, including sociability and fearfulness. The modern dairy calf's rearing environment often lacks environmental and social complexity. This study examined the effects of early-life, non-maternal adult contact and access to a physically complex environment on the responses of dairy heifers to several stressors, including restraint, social isolation, and novelty at 18 months of age. From the age of 2-13 weeks, 60 dairy heifers (Bos taurus) were reared according to one of three treatments applied to 20 calves each: (1) Hand-reared at pasture in groups of ten, with three unrelated dry cows (+S); (2) Hand-reared at pasture in groups of ten (-S); or (3) Hand-reared in sheds in groups of 10-12 as a commercial control (CC). At 13 weeks, all treatment groups were mixed and managed at pasture as a single herd. At 18 months, the responses of 50 heifers to restraint in a crush, social isolation and a novel object were observed (+S = 16, -S = 17, CC = 17). Treatment did not influence responses to restraint or social isolation, but influenced some indicators of fearfulness during exposure to a novel object. Six +S heifers interacted with the novel object compared to 0 -S and one CC, and CC heifers spent around 50% more time in vigilance than +S or -S heifers. Dairy heifers provided with early-life social enrichment in the form of non-maternal adult contact may have reduced fear of novelty. The implications for lifelong ability to adapt to novel situations, such as entry into the milking herd, should be assessed.

Response to novel feed in dairy calves is affected by prior hay provision and presentation method

Animals raised in environments that prevent natural foraging opportunities may have difficulty adapting to novelty, such as feeding and management changes. Our objective was to evaluate how early provision and presentation of forage in dairy calves affected response to novel TMR (total mixed ration; grain and alfalfa) at weaning. Holstein heifer calves were housed individually in a covered outdoor hutch with an attached uncovered wire-fenced pen on sand bedding. Calves were fed a diet of starter grain and milk replacer (5.7-8.4L/d step-up) via a bottle (Control, n = 9) or given additional access to mountaingrass hay presented either in a bucket (Bucket, n = 9), or PVC pipe feeder (Pipe, n = 9). Treatments were applied from birth through 50 d of age, when step-down weaning began. All calves had 3 buckets and a pipe feeder provided in their uncovered pen area. On d 50, each calf was briefly blocked inside their hutch. TMR was put in the 3rd bucket that previously contained hay (Bucket) or was empty (Control, Pipe). The calf was released from the hutch and video-recorded for 30 min. Neophobia towards TMR was affected by prior experience with presentation: Bucket calves began eating TMR faster than Pipe and Control (P≤0.012) and showed the fewest number of startle responses (P = 0.004). Intake was similar across groups (P = 0.978), suggesting this apparent neophobia was transient, but Control calves took longer to eat than Bucket (P<0.001) and Pipe (P = 0.070) calves and were less likely to give up on eating to lie down instead. These results suggest that previous experience with hay improves processing ability when presented with novel TMR. Overall, response to a novel feed is affected by both early life experience, such as opportunities to process forage, and the presentation of the feed itself. Calves also appear motivated to access forage, evidenced by transient neophobia, high intake, and persistence in feeding by naïve calves.

Towards a Positive Welfare Protocol for Cattle: A Critical Review of Indicators and Suggestion of How We Might Proceed

Current animal welfare protocols focus on demonstrating the absence (or at least low levels) of indicators of poor welfare, potentially creating a mismatch between what is expected by society (an assurance of good animal welfare) and what is actually being delivered (an assurance of the absence of welfare problems). This paper explores how far we have come, and what work still needs to be done, if we are to develop a protocol for use on commercial dairy farms where the aim is to demonstrate the presence of positive welfare. Following conceptual considerations around a perceived “ideal” protocol, we propose that a future protocol should be constructed (i) of animal-based measures, (ii) of indicators of affective state, and (iii) be structured according to indicators of short-term emotion, medium-term moods and long-term cumulative assessment of negative and positive experiences of an animal's life until now (in contrast to the current focus on indicators that represent different domains/criteria of welfare). These three conditions imposed the overall structure within which we selected our indicators. The paper includes a critical review of the literature on potential indicators of positive affective states in cattle. Based on evidence about the validity and reliability of the different indicators, we select ear position, play, allogrooming, brush use and QBA as candidate indicators that we suggest could form a prototype positive welfare protocol. We emphasise that this prototype protocol has not been tested in practice and so it is perhaps not the protocol itself that is the main outcome of this paper, but the process of trying to develop it. In a final section of this paper, we reflect on some of the lessons learnt from this exercise and speculate on future perspectives. For example, while we consider we have moved towards a prototype positive welfare protocol for short-term affective states, future research energy should be directed towards valid indicators for the medium and long-term.

The effect of rearing conditions during the milk-fed period on milk yield, growth, and maze behaviour of dairy cows during their first lactation

The objective was to find whether cow growth, milk performance, and behaviour are affected by (1) rearing conditions until weaning after a milk-fed period of 84 d and (2) the sire lineage. Thirty-five Holstein heifers were assigned to one of three treatments: SM, n=13, pen with mother to 21st day, then group pen (they received a maximum of 6 kg of milk daily); SN, n=9, after 3 d with own mother in pen with nursing cow (they received a maximum of 6 kg of milk daily); H, n=13, in hutch from the 2nd to 56th day (6 kg of milk replacer daily), then loose housing pen to weaning (6 kg of milk replacer daily). After weaning at the 84th day, all heifers were kept in pens with the same ration as during calving. During lactation, live body weight (LBW) was measured each month and milk yield each day. Maze learning was evaluated in the fifth month of lactation. The data were analysed using a general linear model ANOVA. At the 30th day, the LBW tended to be the highest in SN (SM 528.2 ± 11.4 kg, SN 571.7 ± 15.3 kg, H 533.2 ± 12.3 kg). When lactation ended, the highest LBW was in SN and the lowest in H (SM 612.6 ± 12.2 kg, SN 623.1 ± 16.4 kg, H 569.8 ± 13.2 kg; P<0.05). The SN tended to have the highest production of milk (SM 7143.9 ± 241.5 kg, SN 7345.1 ± 319.0 kg, H 7146.7 ± 234 kg), and the H for FCM (SM 6290.3 ± 203.2 kg, SN 6307.6 ± 268.4 kg, H 6399.3 ± 197.1 kg) for 305 d lactation. Group SN crossed the maze fastest (SM 1141.4 ± 120.5 s, SN 810.3 ± 160.5 s, H 1120.8 ± 118.6 s). The vocalization number differed significantly (SM 32.3 ± 5.7, SN 20.8 ± 4.4, H 9.9 ± 2.6; P<0.01). The results indicated that the rearing method up to weaning may have an impact on dairy cows' performance and behaviour.

Exploratory behaviour towards novel objects is associated with enhanced learning in young horses

The mechanisms underlying individual variation in learning are key to understanding the development of cognitive abilities. In humans and primates, curiosity has been suggested as an important intrinsic factor that enhances learning, whereas in domesticated species research has primarily identified factors with a negative effect on cognitive abilities, such as stress and fearfulness. This study presents the first evidence of a link between object-directed curiosity and learning performance in young horses in two very different learning tasks (visual discrimination and pressure-release). We exposed young horses (n = 44) to standardised novel object tests at 5 months and 1 year of age and found consistency in responses. Standard indicators of fearfulness (e.g. heart rate and alertness) were unrelated to learning performance, whereas exploratory behaviour towards the novel objects correlated to performance in both learning tasks. Exploratory behaviour was unreinforced in the novel object tests and likely reflects the animal’s intrinsic motivation (i.e. curiosity), suggesting that this trait is favourable for learning performance. In addition to the insights that these results provide into cognition in a domesticated species, they also raise questions in relation to fostering of curiosity in animals and the impact that such manipulation may have on cognitive abilities.

Long-term consistency of personality traits of cattle

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.

Welfare of beef cattle in Australian feedlots: a review of the risks and measures

The rising global demand for animal protein is leading to intensification of livestock production systems. At the same time, societal concerns about sustainability and animal welfare in intensive systems is increasing. This review examines the risks to welfare for beef cattle within commercial feedlots in Australia. Several aspects of the feedlot environment have the potential to compromise the physical and psychological welfare of cattle if not properly monitored and managed. These include, but are not limited to, animal factors such as the influence of genetics, temperament and prior health, as well as management factors such as diet, pen design, resource provision, pregnancy management, and stock-person attitudes and skills. While current industry and producer initiatives exist to address some of these issues, continuous improvements in welfare requires accurate, reliable and repeatable measures to allow quantification of current and future welfare states. Existing measures of welfare are explored as well as proxy indicators that may signal the presence of improved or reduced welfare. Finally, potential future measures of welfare that are currently under development are discussed and recommendations for future research are made.

Evidence for consistent individual differences in rat sensitivity to carbon dioxide

Carbon dioxide (CO₂) gradual-fill is commonly used to kill laboratory rats, but this use remains controversial due to a lack of agreement between studies. Inconsistencies may arise from differences in behaviors measured (e.g. active versus passive behaviors), in how rats cope with threats, or in rat sensitivity to CO₂. The aims of the current study were to 1) describe active and passive responses during CO₂ forced exposure, 2) determine if these responses are consistent within individuals and across aversive stimuli, 3) assess individual differences in aversion to CO₂ in aversion-avoidance and approach-avoidance tests and 4) determine how responses in aversion tests relate to individual differences in behavior during forced exposure. Twelve Sprague Dawley female rats were exposed twice to three treatments: CO₂, oxygen (O₂), and fox scent, and were exposed to CO₂ twice in each aversion test. The change in behavior from baseline was higher for rearing and locomotion when rats were exposed to CO₂ than when exposed to O₂ and fox scent. Responses varied among rats but were consistent across multiple tests within rats. For example, rearing was consistent within individuals between two exposures to CO₂. Similarly, the strength of aversion was consistent within individuals across multiple exposures to CO₂ in aversion-avoidance and approach-avoidance testing. Latency to avoid CO₂ in aversion-avoidance tests was negatively correlated with rearing during CO₂ forced exposure. Collectively, these results indicate that rat responses to CO₂ vary between (but are consistent within) individuals, suggesting that rats vary in CO₂ sensitivity. However, even the less responsive rats avoided CO₂ concentrations far below those necessary to achieve unconsciousness, indicating that all rats likely experience negative states when euthanized with CO₂.

Evaluating the temporal and situational consistency of personality traits in adult dairy cattle

Recent research suggests that personality, defined as consistent individual behavioral variation, in farm animals could be an important factor when considering their health, welfare, and productivity. However, behavioral tests are often performed individually and they might not reflect the behavioral differences manifested in every-day social environments. Furthermore, the contextual and longer-term temporal stability of personality traits have rarely been investigated in adult dairy cattle. In this study, we tested three groups of lactating Holstein cows (40 cows) using an individual arena test and a novel object test in groups to measure the contextual stability of behavior. Among the recorded individual test parameters, we used seven in the final analysis, which were determined by a systematic parameter reduction procedure. We found positive correlations between novel object contact duration in the group test and individual test parameters object contact duration (Rs = 0.361, P = 0.026) and movement duration (Rs = 0.336, P = 0.039). Both tests were repeated 6 months later to investigate their temporal stability whereby four individual test parameters were repeatable. There was no consistency in the group test results for 25 cows tested twice, possibly due to group composition changes. Furthermore, based on the seven individual test parameters, two personality traits (activity/exploration and boldness) were identified by principal component analysis. We found a positive association between the first and second tests for activity/exploration (Rs = 0.334, P = 0.058) and for boldness (Rs = 0.491, P = 0.004). Our results support the multidimensional nature of personality in adult dairy cattle and they indicate a link between behavior in individual and within-group situations. The lack of stability according to the group test results implies that group companions might have a stronger influence on individual behavior than expected. We suggest repeating the within-group behavioral measurements to study the relationship between the social environment and the manifestation of personality traits in every-day situations.

Dairy cattle welfare as a result of human-animal relationship – a review

Despite the various concepts of human-animal relationship, the welfarist approach to this problem is one of the most often considered in theory and used in practice. When dealing with issues related to dairy cattle welfare (DCW), it is necessary to take into account both the reality characteristic for animals used to obtain milk (e.g. the problem of automatic milking of cows) and for slaughter cattle (e.g. slaughter of culled animals). It is not surprising, therefore, that issues related to DCW are the focus of the attention of the public, researchers, breeders as well as the dairy and meat industries. The aim of this article was to possibly most comprehensively cover the above-mentioned issues, although due to its huge scope it was obviously necessary to limit the article to what I think are currently most important issues. That is why in the review I (1) characterized the issues related to the division of human responsibility for DCW; (2) discussed the importance of technology to human-animal relationship; (3) elaborated the matter of stress, emotionality of animals and their cognitive abilities in the aspect of “negative” and “positive” DCW; (4) considered the possibilities of non-invasive assessment of animal welfare in the future and (5) discussed topics related to improving the conditions of the slaughter of animals. In summary, it was proposed paying more attention than has been paid until now, to the assessment of positive DCW in scientific research and breeding practice. I also drew attention to the necessity of reliable information flow on the line of the breeder/milk producer - industry - consumer, as negligence in this area is one of the reasons for public disinformation regarding the level of animal welfare.

Novel object response in beef cattle grazing a pasture as a group

This study was conducted to investigate how cattle (Bos taurus) respond to objects presented for the first time and repeatedly in a stimulus-rich environment where they can freely graze and interact with conspecifics. Twenty-five Japanese Black cows were subjected to three repeats of a novel object test in which animals stocked on a pasture as a group were exposed to the same and different objects across the test repeats. Responses of cows towards the objects were quantified by both approach (entering within a 0.5-m distance of the object) and contact (physical touch with the object) measures as occurrence (1 or 0) and number of reactions and latency to the first reaction. Cows were consistent in the approach to the first-time objects (repeatability = 0.39-0.62, Kendall's W = 0.58, P <  0.05), but not in the approach to the repeatedly presented objects or in the contact with both types of objects (P > 0.05). Individuals which consistently approached the novel objects could be regarded as highly exploratory and/or bold in personality. Future work should consider novel object response in cattle across a range of contexts.