Fear of humans and its relationships with productivity in laying hens at commercial farms

Development and evaluation of an animal health and welfare monitoring system for veterinary supervision of pullet farms

Regular welfare monitoring throughout rearing of pullets may help to identify problems early and take counteractions timely, which helps in guaranteeing good welfare. The aims of our observational study were (i) to establish and test a welfare monitoring system that can be used during (short) routine veterinary and technical staff visits for pullet flocks, (ii) to use the monitoring system to investigate variability between flocks and (iii) to analyse factors that potentially affect pullets' body weight, uniformity in body weight and mortality. The developed monitoring system tries to minimise the time required while not losing important information. Age-specific recording sheets comprise animal-based indicators of welfare and relevant environmental factors (housing, management, care) to allow for identifying causes of problems and targeted action. Finally, the system was implemented in a cross-sectional study and data collected in 100 flocks (67 organic, 33 conventional) on 28 rearing farms in Austria. Linear mixed models were used to identify factors influencing body weight, uniformity and mortality, both including all flocks (A) and only organic flocks (O) and a linear regression model with all flocks to investigate associations within animal-based indicators. High variability was found between flocks in animal-based indicators. Body weight was higher when the pre-rearing period was shorter (p ≤ 0.001, A&O), with higher intensities of light (p = 0.012, O), with only one compared to more stockpersons (p ≤ 0.007, A&O), with a higher number of flock visits per day (p ≤ 0.018, A&O), and a lower avoidance distance (p = 0.034, A). Body weight uniformity increased, with age and decreased with the duration of the light period (p = 0.046, A), and, amongst others, was higher on organic farms (farming type; p = 0.041). The latter may reflect a more uniform level of welfare due to a lower stocking density and lowered effects of social competition. Within organic flocks mortality was lower if pullets had access to a covered veranda (p = 0.025) resulting in an overall lower stocking density inside the barn, while in the model including all farms mortality was higher in cases where a disease had been diagnosed. We conclude that our monitoring system can easily be implemented in regular veterinary and technical staff visits, but could also be used by the farmers'. Several easy-to-record animal-based indicators of animal welfare could be analysed more frequently to increase early detection of problems. Implementation of such a routine-based monitoring system with easy-to-assess animal-based parameters and input measures can contribute to better animal health and welfare in pullets.

Fearfulness in Commercial Laying Hens: A Meta-Analysis Comparing Brown and White Egg Layers

High fearfulness in commercial laying hens can negatively affect production parameters and animal welfare. Brown and white egg layers differ in several behavioral characteristics, though reported differences in fearfulness are inconsistent. A meta-analysis was conducted to determine whether there are systematic differences in measures of fearfulness between brown and white layers. Twenty-three studies that examined either 1 or both of 2 behavioral tests were included: tonic immobility (TI) (longer duration = higher fearfulness, 16 studies) and novel object (NO) test (lower approach rate = higher fearfulness, 11 studies). The 2 tests were analyzed separately. TI analyses: A generalized linear mixed effect model (GLMM) with a lognormal distribution was fitted to describe the data with experiment nested in study as a random effect. Explanatory (X) variables were considered through backward selection, where potential X-variables included color (brown vs. white layers), decade (1980s, 2000s, 2020s), age (prelay vs. in lay), genetic stock (hybrid vs. grand-/parent stock), and methodology (back vs. side position). NO test analyses: univariable GLMMs with a beta distribution were fitted with approach rate as the Y-variable and color, decade, age, stock, or 2 methodological factors (test duration, single vs. group testing) as X-variables. Models were evaluated by assessing information criteria, residuals/random effect normality, significance of X-variables and model evaluation statistics (mean square prediction error, concordance correlation coefficient). TI duration was best explained by a color-by-decade interaction (P = 0.0006). Whites in the 1980s had longer TI durations (709.43 ± 143.88 s) than browns in the 1980s (282.90 ± 59.70 s), as well as in comparison to browns (208.80 ± 50.82 s) or whites (204.85 ± 49.60 s) in the 2020s. The NO approach rate was best explained by color (P ≤ 0.05 in 3 models), age (P < 0.05 in 3 models), and decade (P = 0.04). Whites had a higher approach rate (0.7 ± 0.07) than browns (0.5 ± 0.11), birds in lay a higher rate (0.8 ± 0.07) than birds prelay (0.4 ± 0.12), and approach rate for papers published in the 2000s (0.8 ± 0.09) was higher than in the 2020s (0.2 ± 0.12). The phylogenetic difference in the 1980s was no longer detectable after enforcing an upper limit on TI durations (10 min), as became common practice in later studies. Our findings suggest that phylogenetic differences in fearfulness and changes over time are test dependent, and this raises important questions and potential consequences for assessing hen welfare in commercial egg production.

The Animal-Human Interface in Farm Animal Production: Animal Fear, Stress, Reproduction and Welfare

Simple Summary

For at least the last four decades, the focus of animal welfare research, quality assurance, and policy initiatives has been on measuring behavioural and physiological stress responses in animals. In the last decade, however, this focus of animal welfare research has shifted to the consequences of these behavioural and physiological stress responses rather than only the responses per se. Modern-day farming, even with the intensification and automation requires regular monitoring and interactions by stockpeople. Research conducted in both experimental and commercial settings has shown widespread effects of the human-animal interactions on behaviour, physiology, and reproductive performance in farm animals. In this paper, we review the implications of human-animal interactions on reproduction in farm animals.

Abstract

A negative human-animal relationship (HAR) from the perspective of the animal is a limiting factor affecting farm animal welfare, as well as farm animal productivity. Research in farm animals has elucidated sequential relationships between stockperson attitudes, stockperson behaviour, farm animal fear behaviour, farm animal stress physiology, and farm animal productivity. In situations where stockperson attitudes to and interactions with farm animals are sub-optimal, through animal fear and stress, both animal welfare and productivity, including reproductive performance, can be compromised. There is a growing body of evidence that farm animals often seek and enjoy interacting with humans, but our understanding of the effects of a positive HAR on stress resilience and productivity in farm animals is limited. In this review, we explore the pathways by which stress induced by human-animal interactions can negatively affect farm animal reproduction, in particular, via inhibitory effects on the secretion of gonadotrophins. We also review the current knowledge of the stockperson characteristics and the nature of stockperson interactions that affect fear and physiological stress in farm animals. The contents of this review provide an insight into the importance of the HAR on farm animal welfare and reproduction while highlighting the gap in knowledge regarding the effects of a positive HAR on farm animals.

Differences in resource acquisition, not allocation, mediate the relationship between behaviour and fitness: a systematic review and meta-analysis

Within populations, individuals often show repeatable variation in behaviour, called 'animal personality'. In the last few decades, numerous empirical studies have attempted to elucidate the mechanisms maintaining this variation, such as life-history trade-offs. Theory predicts that among-individual variation in behavioural traits could be maintained if traits that are positively associated with reproduction are simultaneously associated with decreased survival, such that different levels of behavioural expression lead to the same net fitness outcome. However, variation in resource acquisition may also be important in mediating the relationship between individual behaviour and fitness components (survival and reproduction). For example, if certain phenotypes (e.g. dominance or aggressiveness) are associated with higher resource acquisition, those individuals may have both higher reproduction and higher survival, relative to others in the population. When individuals differ in their ability to acquire resources, trade-offs are only expected to be observed at the within-individual level (i.e. for a given amount of resource, if an individual increases its allocation to reproduction, it comes at the cost of allocation to survival, and vice versa), while among individuals traits that are associated with increased survival may also be associated with increased reproduction. We performed a systematic review and meta-analysis, asking: (i) do among-individual differences in behaviour reflect among-individual differences in resource acquisition and/or allocation, and (ii) is the relationship between behaviour and fitness affected by the type of behaviour and the testing environment? Our meta-analysis consisted of 759 estimates from 193 studies. Our meta-analysis revealed a positive correlation between pairs of estimates using both survival and reproduction as fitness proxies. That is, for a given study, behaviours that were associated with increased reproduction were also associated with increased survival, suggesting that variation in behaviour at the among-individual level largely reflects differences among individuals in resource acquisition. Furthermore, we found the same positive correlation between pairs of estimates using both survival and reproduction as fitness proxies at the phenotypic level. This is significant because we also demonstrated that these phenotypic correlations primarily reflect within-individual correlations. Thus, even when accounting for among-individual differences in resource acquisition, we did not find evidence of trade-offs at the within-individual level. Overall, the relationship between behaviour and fitness proxies was not statistically different from zero at the among-individual, phenotypic, and within-individual levels; this relationship was not affected by behavioural category nor by the testing condition. Our meta-analysis highlights that variation in resource acquisition may be more important in driving the relationship between behaviour and fitness than previously thought, including at the within-individual level. We suggest that this may come about via heterogeneity in resource availability or age-related effects, with higher resource availability and/or age leading to state-dependent shifts in behaviour that simultaneously increase both survival and reproduction. We emphasize that future studies examining the mechanisms maintaining behavioural variation in populations should test the link between behavioural expression and resource acquisition - both within and among individuals. Such work will allow the field of animal personality to develop specific predictions regarding the mediating effect of resource acquisition on the fitness consequences of individual behaviour.

Impact of male-female cohabitation period on behavioral aspects, fertility, hatchability, and hormonal estimates of Japanese quail

To evaluate the impact of male-female cohabitation period on the fertility, hatchability, injuries response, and some hormonal estimates in Japanese quails. A total of 288 mature Japanese quails were equally divided into 3 groups (3 groups × 8 replicates × 12 birds), with 1 Male: 2 Females sex ratio. In the first group (control), male and female quails were reared continuously together, while the males in the second and third groups were reared together with females once or twice/wk times (24 h/ time), respectively throughout the experiment. The obtained results showed that final body weight (FBW/g), fertility (%), and hatchability (%) in the second and third groups significantly (P ≤ 0.01) increased compared with the control group. Laying quails in the second and third groups significantly (P ≤ 0.01) produced more and heavier eggs, while the feed consumption and feed conversion ratio were significantly (P ≤ 0.01) decreased compared with the control group. The injuries response for both sex in the second and third groups significantly (P ≤ 0.01) decreased compared with the control group. The cloacal size (mm²) for quails in the third group significantly (P ≤ 0.01) increased than those of the first and second groups, while the testes (%) were not affected. The testosterone hormone concentration for male chickens in the second and third groups significantly (P < 0.01) decreased, while the female progesterone hormone concentration (ng/mL) significantly (P < 0.01) increased compared with the control group. The means of red blood cells (RBC/106), white blood cells (WBC/103), and hemoglobin (g/dL) for quails in the second and third groups significantly (P < 0.01) increased, while heterophil/lymphocyte (H/L ratio) significantly (P < 0.01) decreased compared with the control group. Thus, it could be concluded that the reduction male-female cohabitation period of quails is recommended for improving the fertility and hatchability percentages as well as and some hormonal estimates.

Physiological factors influencing female fertility in birds

Fertility is fundamental to reproductive success, but not all copulation attempts result in a fertilized embryo. Fertilization failure is especially costly for females, but we still lack a clear understanding of the causes of variation in female fertility across taxa. Birds make a useful model system for fertility research, partly because their large eggs are easily studied outside of the female's body, but also because of the wealth of data available on the reproductive productivity of commercial birds. Here, we review the factors contributing to female infertility in birds, providing evidence that female fertility traits are understudied relative to male fertility traits, and that avian fertility research has been dominated by studies focused on Galliformes and captive (relative to wild) populations. We then discuss the key stages of the female reproductive cycle where fertility may be compromised, and make recommendations for future research. We particularly emphasize that studies must differentiate between infertility and embryo mortality as causes of hatching failure, and that non-breeding individuals should be monitored more routinely where possible. This review lays the groundwork for developing a clearer understanding of the causes of female infertility, with important consequences for multiple fields including reproductive science, conservation and commercial breeding.

Researching Human-Cattle Interaction on Rangelands: Challenges and Potential Solutions

Simple Summary

Research investigating the influence of human-animal interactions on beef cattle production and welfare often occurs during stress-inducing contexts, such as restraint and transport. Given that beef cattle which graze on expansive rangelands do not frequently interact with humans, assessment of animal response to humans may be inaccurate if they are only recorded during such stressful context. Future research aimed at identifying the causes and impacts of individual human–cattle relationships may consider conducting experiments while the cattle are in a low stress context, such as while ruminating, resting, or, grazing. By adapting methods used to research wildlife response to humans, researchers may be able to better understand how animal personality and previous experience can influence cattle production and welfare.

Abstract

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).

Stress, health and the welfare of laying hens

It is essential to understand responses to stress and the impact of stress on physiological and behavioural functioning of hens, so as to assess their welfare. The current understanding of stress in laying hens is comprehensively reviewed here. Most research on stress in hens has focussed on the activity of the adrenal glands, with the most common approach being to measure corticosterone, which is the predominant glucocorticoid produced by birds in response to stress. While these measures are useful, there is a need to understand how the brain regulates stress responses in hens. A greater understanding of the sympathoadrenal system and its interaction with the hypothalamo–pituitary–adrenal axis is required. There is also a lack of knowledge about the many other peptides and regulatory systems involved in stress responses in hens. The usefulness of understanding stress in hens in terms of assessing welfare depends on appreciating that different stressors elicit different responses and that there are often differences in responses to, and impacts of, acute and chronic stress. It is also important to establish the actions and fate of stress hormones within target tissues. It is the consequences of these actions that are important to welfare. A range of other measures has been used to assess stress in hens, including a ratio of heterophils to lymphocytes and haematocrit:packed cell-volume ratio and measures of corticosterone or its metabolites in eggs, excreta, feathers and the secretions of the uropygial gland. Measures in eggs have proffered varying results while measures in feathers may be useful to assess chronic stress. There are various studies in laying hens to indicate impacts of stress on the immune system, health, metabolism, appetite, and the quality of egg production, but, generally, these are limited, variable and are influenced by the management system, environment, genetic selection, type of stressor and whether or not the birds are subjected to acute or chronic stress. Further research to understand the regulation of stress responses and the impact of stress on normal functioning of hens will provide important advances in the assessment of stress and, in turn, the assessment of welfare of laying hens.

Natural behaviours, their drivers and their implications for laying hen welfare

Some believe that farm animals need to be kept in conditions that provide ‘natural’ aspects in the animal’s environment and, thus, provide the opportunity for the animals to perform their full ‘behavioural repertoire’. Captivity may restrict either behaviours that animals have instinctive, intrinsic propensities to perform whatever the environment or behaviours that are elicited by deficits in the animals’ environment. Behavioural restriction may also thwart general motivation to seek variety and/or avoid monotonous conditions. Appreciating whether an animal suffers if deprived of the opportunity to perform natural behaviour requires, first, an understanding of how the behaviour in question is elicited and controlled, the effects of early experience and genetics on the behaviour and the behaviour of the species in the wild, and, second, the behavioural, physiological and fitness effects of deprivation of the behaviour. Housing laying hens in conventional cages compromises their behavioural repertoire, such as nesting in a nest box, dust bathing, perching and foraging, and the present review focuses on the welfare implications if these natural behaviours are thwarted in modern poultry production. A floor space of &lt;561 cm2/hen increases physiological stress, reduces egg production and increases mortality in laying hens. There is also evidence of behavioural restriction in terms of reduced wing stretching, leg stretching, tail wagging, locomotion, floor and object pecking and preening with floor space in the range of 542–750 cm2/hen. Preference and motivation research has indicated that laying hens value resources such as nest boxes for oviposition, substrates for foraging and dust bathing, and perches for roosting. However, there is no convincing evidence that deprivation of these resources results in physiological stress. Furthermore, apart from adverse effects of the absence of perches on bone strength, there is no evidence that deprivation of nest boxes, perches, and foraging and dust-bathing substrates results in reduction in fitness such as reduced egg production or health. Nevertheless, preference research has indicated that the opportunity to utilise these resources, particularly nest boxes, may elicit positive emotional states in laying hens. Therefore, it is important to understand both how motivated the animal is to choose an option or perform a behaviour as well as the consequences of depriving the animal of this opportunity.

The Human-Animal Relationship in Australian Caged Laying Hens

Simple Summary

Stockperson behaviour can influence fear of humans and welfare of farm animals. This study observed the human-animal relationship (HAR) in 19 Australian caged laying hen flocks to determine whether stockperson behaviour was associated with behavioural indicators of fear of humans and stress in caged laying hens. The average avoidance response of each flock toward an approaching human was assessed using two behavioural tests, and stress was measured using the concentration of corticosterone in an egg sample collected immediately prior to these observations. Stockperson behaviour was observed for 2 days in each flock and compared to hen fear. Unexpectedly, no relationships were found between the observed stockperson behaviour and avoidance of humans in the hens, but flocks were more productive when they showed less avoidance of humans, and when stockpeople made less noise in the laying house. This suggests that stockperson behaviour and hen fear may influence productivity, but there was no evidence that any effect of fear on productivity was caused by stockperson behaviour. Unexpectedly, the most fearful flocks also had the lowest stress levels. These results clearly need further research to be fully understood but could not confirm the existence of the HAR on caged egg farms in Australia.

Abstract

Studies on farm animals have shown relationships between stockperson attitudes and behaviour and farm animal fear, stress and productivity. This study investigated how the avoidance behaviour of Australian commercial caged laying hens may be related to stockperson behaviour, albumen corticosterone, and the number of weeks producing within 5% of peak egg production. Nineteen laying houses were assessed over 3 days. Fear of humans in hens, based on their avoidance response to an unfamiliar human, was assessed using two behavioural tests. Albumen corticosterone concentrations were measured from egg samples collected immediately prior to behavioural testing. Stockperson attitudes were assessed using a questionnaire and stockperson behaviour was observed over 2 days. Productivity records for each laying house were also obtained. The duration of peak production was negatively related to both noise made by the stockperson and hen avoidance. No relationship between stockperson behaviour or attitudes and hen avoidance was found, but stockpeople with negative attitudes made more noise. In conclusion, this study could not confirm a relationship between stockperson behaviour and hen avoidance behaviour for Australian caged laying hens. However, this study did confirm a relationship between hen avoidance behaviour, albumen corticosterone concentration, and the duration of peak egg production.

Invited review: Examining farmers' personalities and attitudes as possible risk factors for dairy cattle health, welfare, productivity, and farm management: A systematic scoping review

We aimed to determine how research regarding farmers' personalities and attitudes as risk factors is reported (methodological approaches to assessing, extracting, and processing data and analyzing risk factors) and to explore evidence for the effect of farmers' attitudes and personalities on dairy cattle health, welfare, productivity, and management. Therefore, we conducted a systematic review of studies on personality and attitude as risk factors for dairy cattle health, welfare, productivity, and farm management. Database searches captured 1,144 records, and 38 were finally included in the review. Thirty-three manuscripts assessed farmers' attitudes, 1 assessed their personalities, and 4 assessed both as risk factors. These potential risk factors were checked for relationships with more than 50 different outcome variables regarding farm management (17 manuscripts), animal health (13 manuscripts), animal productivity (11 manuscripts), and animal welfare (4 manuscripts). The approaches to assessing risk factors and processing and interpreting data varied greatly; thus, drawing conclusions regarding the effects of attitude and personality as risk factors is impeded because manuscripts are difficult to compare. Our findings highlight the need for harmonization of attitudes and personality assessments in future research. Furthermore, researchers should carefully consider which depth of detail to apply when planning and evaluating related research. Nevertheless, results highlight the importance of the effect of personality and attitude on outcomes. Farmers' personality and attitudes are associated with dairy cattle health, welfare, productivity, and management. In general, attitudes indicating higher degrees of technical knowledge, affection with problems, perceived responsibility, perception of control of a situation, a better human-animal relationship, or a positive evaluation of the benefits of management decisions tended to affect outcomes in a beneficial way. "Agreeableness" and "conscientiousness" were shown to promote better farm performance, whereas "neuroticism" had a negative effect. Therefore, further research on attitude and personality and their consideration by professionals and decision-makers within the dairy sector and politics is strongly recommended. This might provide the chance to better understand the needs of dairy farmers and therefore develop tailored advice and support strategies to improve both satisfactory and constructive cooperation.

Human-animal interactions in agriculture and their impact on animal welfare and performance

Human-animal interactions are a common feature of modern intensive farming systems and these interactions may have marked consequences on animal productivity and welfare. Research in agriculture has shown interrelationships between the stockperson’s attitudes and behaviour and the behaviour, productivity and welfare of farm animals and the following model of human-animal interactions in agriculture has been proposed. Because a stockperson’s behaviour towards animals is largely under volitional control, this behaviour is strongly influenced by the attitudes that the stockperson holds about the animals. These attitudes and consequent behaviours predominantly affect the animal’s fear of humans which, in turn, affects the animal’s performance and welfare. The mechanism whereby fear affects performance and welfare appears to be through a chronic stress response. The risk to welfare also arises if the stockperson’s attitude and behaviour towards the animals are negative because the stockperson’s commitment to the surveillance of, and the attendance to, welfare issues is likely to be highly questionable.

Recent research in the pig industry has shown that a training programme targeting the key attitudes and behaviour of stockpersons produced improvements in stockperson attitudes and behaviour and animal behaviour and productivity. These results indicate the potential to improve animal productivity and welfare by targeting the stockperson’s attitudes and behaviour for improvement. Techniques which may be useful in this regard include staff selection and training procedures addressing these important human attributes.

The farmers’ influence on calves’ behaviour, health and production of a veal unit

Although veal production is a highly standardized system, there still remains considerable variability in productivity between units. This variability might be due to the farmers working on these units, through differences in stockmanship, work attitudes or behaviour, which in turn may affect animals’ fear responses, productivity and health. A survey was conducted on 50 commercial farms affiliated to the same veal company. All units had calves housed in individual crates, a similar number of crates, and the same diets and management advice. Data were collected on: building and general farm characteristics, farmers’ backgrounds and their attitudes towards their work and calves, farmers’ behaviour with the calves, calves’ reactivity to people, and disease level of the calves. Productivity results (growth rates, food efficiency and mortality) were used to classify veal units as ‘high producing’ (no. = 24) v. ‘moderate producing’ (no. = 26). Calves were less reactive to people in units where the farmer behaved sympathetically and where there were several stockpersons working. The disease level was lower in units where the farmer had a positive attitude towards the sensitivity of the calves to contact and towards the importance of cleaning. Productivity of the veal unit was associated with the health of the calves but not with their reactivity to people.

It is suggested that the farmer can have an influence on the success of the veal unit mainly through his/her ability to control the health of the calves and that a positive attitude towards animals and towards work (specifically cleaning actions) can improve the accuracy of surveillance and care of the animals. Moreover, through his/her behaviour with the calves and his/her ability to control their health, the farmer can play an important rôle in assuring calves’ welfare.

Air Quality in Alternative Housing Systems may have an Impact on Laying Hen Welfare. Part II-Ammonia

The EU ban on conventional barren cages for laying hens from 2012 has improved many aspects of laying hen welfare. The new housing systems allow for the expression of highly-motivated behaviors. However, the systems available for intensive large-scale egg production (e.g., aviaries, floor housing systems, furnished cages) may cause other welfare challenges. We have reviewed the literature regarding the health, behavior, production characteristics, and welfare of laying hens when exposed to ammonia in their housing environment. Concentrations of ammonia gas are commonly high in aviaries and floor housing systems in which manure is not regularly removed, whereas they are usually lower in furnished cages. High levels are found during the cold season when ventilation flow is often reduced. Ammonia is a pungent gas, and behavioral studies indicate chickens are averse to the gas. High concentrations of gaseous ammonia can have adverse health effects and, when very high, even influence production performance. The most profound effects seen are the occurrence of lesions in the respiratory tract and keratoconjunctivitis. There is also evidence that high ammonia concentrations predispose poultry to respiratory disease and secondary infections. We conclude that there are animal welfare challenges related to high ammonia levels, and that immediate actions are needed. Development of improved systems and management routines for manure removal and ventilation will be important for the reduction of ammonia levels and hence will contribute to safeguarding hen welfare.

Short- and long-term effects of unpredictable repeated negative stimuli on Japanese quail's fear of humans

Numerous aversive events occur in poultry production, and if repeated and unpredictable, can result in an impaired welfare. Some events such as handling can be perceived negatively and it is of interest to understand how humans' behaviour could affect poultry's behaviours and especially its avoidance of humans. Our aim was to evaluate short- and long-lasting effects of a 3-week procedure involving unpredictable repeated negative stimuli (URNS) applied during the post-juvenile period on quail's reactivity to humans. We compared the reactions of two sets of quail: URNS was applied to one set (treated quail) and the other set was left undisturbed (control quail). When two weeks old, treated quail were exposed to a variety of negative stimuli, either applied automatically or involving human presence. One and seven weeks after the termination of the procedure, the reactivity of control and treated quail to a passive human being was evaluated. Furthermore, the experimenter with her hand on a trough containing a mealworm assessed the propensity of quail of both groups to habituate to feed close to a human being. In the presence of a seated observer, treated quail were more inhibited and more alert than control quail. Likewise, seven weeks after the end of the URNS procedure, more treated than control quail adopted a fear posture. Moreover, whereas control quail spent as much time in the different areas of their cages, treated quail spent more time in the rear part of their cages. Finally, whereas control quail habituated gradually to feed near the experimenter's hand, treated quail did not. All these tests evidence negative short- and long-term effects on treated quail's reactivity to a passive human being and on their habituation to a human being when her presence is positively reinforced. This highlights the importance of young poultry's experience with humans in production.

The effect of keel fractures on egg production, feed and water consumption in individual laying hens

The impact of keel bone fractures on egg production, egg weight and feed and water consumption in individual laying hens. A total of 165 Lohmann brown laying hens were obtained from a commercial farm that consisted of 105 with keel fractures and 60 without keel fractures. 2. After a 4-d period of acclimatisation, hens were individually housed and provided with ad libitum food and water for a 24-h period. The number of eggs laid, egg weight, feed and water consumption during this period were recorded. Keel bone strength was also assessed. 3. Hens free from keel fractures laid more eggs (91.7% vs. 84.9%) of significantly heavier weight (61.9 g vs. 60.2 g), ate less feed (139 g vs. 151 g) and drank less water (212 ml vs. 237 ml) than hens with fractures. 4. There was a significant positive association between keel fracture severity and water consumption, and a significant negative association between keel fracture severity and egg weight and keel bone strength. 5. This small-scale study on individual birds shows that keel bone fractures may have an impact on the economics of egg production.

Changes in heat shock protein 70, blood parameters, and fear-related behavior in broiler chickens as affected by pleasant and unpleasant human contact

An experiment was conducted to determine the effects of combining both pleasant and unpleasant contacts with human beings on physiology and behavior of broiler chickens. Birds were subjected to the following treatments: (i) received no physical or visual contact with humans (control); (ii) from d 1 to 28, chicks were individually stroked gently for 30 s once daily (PL); (iii) from d 1 to 28, chicks were picked up individually, suspended by both legs, exposed to recorded noise, and swung gently for 15 s once daily (UNPL); (iv) from d 1 to 14 and from d 15 to 28, chicks were subjected to PL and UNPL, respectively (PL-UNPL); and (v) from d 1 to 14 and from d 15 to 28, chicks were subjected to UNPL and PL, respectively (UNPL-PL). On d 42, birds from each treatment group were road-transported for 3 h. Heat shock protein (hsp) 70 expression, plasma levels of corticosterone, serum creatine kinase concentration, heterophil/lymphocyte ratios (HLR), and tonic immobility duration were determined pre- and posttransit. There were significant (P < 0.05) duration of transportation × human contact treatment interactions for HLR and hsp 70 density. Following transit, the PL chicks had significantly (P < 0.05) lower HLR and greater hsp 70 density than the other groups. The corticosterone of PL and UNPL chicks were lower than their control, PL-UNPL, and UNPL-PL counterparts. The PL and PL-UNPL treatments were effective in shortening tonic immobility duration significantly (P < 0.05). Except for UNPL-PL, the serum creatine kinase activity of PL was significantly lower than the other groups. In conclusion, subjecting birds to pleasant human contact reduced stress and fear reactions to transportation by enhancing the ability to express hsp 70 in the brain. Unpleasant human contact had adverse effect on the birds' response to transportation. Early age pleasant experience with humans failed to negate the adverse effects of subsequent unpleasant contact.

Gastrointestinal tract morphological alteration by unpleasant physical treatment and modulating role of Lactobacillus in broilers

1. An experiment was conducted to determine the effects of supposedly unpleasant physical treatment on broiler performance, small intestinal development and ameliorating role of probiotics. 2. The following treatments were applied from day one: (1) chicks exposed to normal human contact fed basal diet (control); (2) chicks were exposed to unpleasant physical treatment and fed basal diet (UPT-BD); and (3) chicks were exposed to unpleasant physical treatment and fed basal diet supplemented with Lactobacillus (UPT-BDL). Chicks were exposed to UPT from days 1 to 21. Different segments of gastrointestinal tract were sampled at 14, 28, 35 and 42 d of age. 3. Broilers of UPT-BD had lower feed consumption compared with control group at 7 d of age. Overall, UPT-BDL birds showed higher body weight gain (BWG) and better feed conversion ratio (FCR) over the course of the experiment. 4. Birds of UPT-BD had lower concentrations of lactic, propionic and butyric acids in the caecum as compared with other groups at 14 d of age. Acetic acid concentration was profoundly decreased in both UPT groups compared to the control. 5. Duodenal villus height of UPT-BD broilers showed a slight reduction compared to the control and UPT-BDL birds at 14 d of age. Afterwards until day 42, UPT-BDL birds showed the highest villus height among treatments in different parts of the small intestine. 6. The results suggested that, even though UPT did not have significant inhibitory effects on the development of the small intestine and broiler performance, it negatively affected bacterial metabolic end products in the caecum, which could be ameliorated by the addition of Lactobacillus.

A comparative approach to the study of Keeper-Animal Relationships in the zoo

Research on intensively farmed animals over the past 25 years has shown that human-animal interactions, by affecting the animal's fear of humans, can markedly limit the productivity and welfare of farm animals. This article begins to explore some of the factors that need to be considered to investigate Keeper-Animal Relationships (KARs) in the zoo. In the mid-1990s, a large body of multi-institutional data on zookeepers and animals was collected from 46 Zoos. Using standardized questionnaires, 82 keepers rated how they behaved towards animals, their husbandry routine, how the animal responds to them and to other people, and provided information about themselves. These data include 219 individuals of four endangered species: black rhinoceros, cheetah, maned wolf, and great hornbill. At each zoo, keepers were also videotaped calling to their animals in order to directly observe animal responses to keeper behaviors. Principle Components Analysis reduced eight animal variables to three components and ten keeper variables to five components. Scores for animals and for keepers were calculated on these components and compared, according to five predictions based on models of human-animal interactions in the literature. Animal responses to keepers varied along three dimensions: Affinity to Keeper, Fear of People, and Sociable/Curious. Animal scores of Fear of People were significantly and positively correlated with independent measures of poor welfare from two later studies: fecal corticoid concentrations for 12 black rhinos and "tense-fearful" scores for 12 cheetahs. (1) Significant species differences were found for Affinity to Keeper and Fear of People, and the interaction of these two dimensions of animal response to keepers appears to be species-specific. (2) The quality of KAR is influenced by whether the zookeeper goes in the enclosure with the animal or not, the frequency and time of feeding, and keeper visibility to the animal. Among keepers who go in with their animals, a significant negative correlation between Frequency of Feeding/Early Feedtime and average Affinity to Keeper of their animals, and a positive correlation between Keeper Experience and their animals' Fear of People, indicates that certain zoo keeping styles or habits among experienced keepers might be aversive and increase fear among animals. (3) Keepers who locomote or make unexpected noises when calling their animals elicit increased aggression or apprehension from maned wolves and cheetahs. (4) Wild-born black rhino and parent-reared maned wolf have significantly less affinity to keepers than their captive-born or hand-reared counterparts, but neither differs in Fear of People. (5) Keeper-animal relationships are likely to be reciprocal as evidenced by a negative correlation of Job Satisfaction with animal Fear of People. Future research directions are discussed with respect to assessment of keeper attitudes and behaviors, animal fear, positive measures of welfare, and positive reinforcement training.

The integration of human-animal relations into animal welfare monitoring schemes

There are increasing local and international pressures for farm animal welfare monitoring schemes. Housing of farm animals is a contentious issue for many, although the impact of the housing system may be overestimated by some. In contrast, the topic of stockmanship has received relatively little attention, even though research has shown that animal carers or stockpeople have a major impact on the welfare of their livestock. While welfare monitoring schemes are likely to improve animal welfare, the impact of such schemes will only be realised by recognising the limitations of stockpeople, monitoring ‘stockmanship’ and providing specific stockperson training to target key aspects of stockmanship. Appropriate strategies to recruit and train stock-people in the livestock industries are integral to safeguarding the welfare of livestock. Monitoring the key job-related characteristics of the stockperson, attitudes to animals and to working with these animals, empathy, work motivation and technical knowledge and skills, provides the opportunity to detect deficits in stockmanship and the necessity for further targeted training. Due to the strong relationships between stockperson attitudes and behaviours and animal fear responses, as well as the relationships between attitudes and other job-related characteristics, we believe attitudes, together with empathy, work motivation and technical knowledge and skills, should be the principal focus of measuring stockmanship in on-farm welfare monitoring schemes.

Are animal personality traits linked to life-history productivity?

Animal personality traits such as boldness, activity and aggressiveness have been described for many animal species. However, why some individuals are consistently bolder or more active than others, for example, is currently obscure. Given that life-history tradeoffs are common and known to promote inter-individual differences in behavior, we suggest that consistent individual differences in animal personality traits can be favored when those traits contribute to consistent individual differences in productivity (growth and/or fecundity). A survey of empirical studies indicates that boldness, activity and/or aggressiveness are positively related to food intake rates, productivity and other life-history traits in a wide range of taxa. Our conceptual framework sets the stage for a closer look at relationships between personality traits and life-history traits in animals.

Genetic Engineering and Other Factors That Might Affect Human-Animal Interactions in the Research Setting

Evidence exists, particularly in the welfare literature of nonhuman animals on the farm, that the interaction between nonhuman animals and the personnel who care for them can have a strong effect on the animals' behavior, productivity, and welfare. Among species commonly used for biomedical research, mice appear to be the least-preferred species in animal care facilities. A review of the literature and observations of animal care staff interacting with mice indicated that the following factors may influence this: their small size, their particular behavioral characteristics, and husbandry constraints (such as housing in ventilated racks). In addition, this study questioned whether animal care personnel have a different perception of genetically engineered animals and whether this, in turn, has an effect on their interactions with these animals. The ability to carefully observe an animal's behavior is key in carrying out an animal-wellness assessment and in minimizing pain and distress. Attention to human-animal interactions in the research setting represents an opportunity for refinement for large numbers of animals and potentially for reduction of animal use.

Temperament in preweanling horses: development of reactions to humans and novelty, and startle responses

The purpose of this study was to investigate the development and the stability across situations and over time of three temperament traits in young foals: propensity to react to humans, propensity to react to novelty, and propensity to react to suddenness. In a comparative study, we examined the reactions of animals in three independent groups (N = 27) tested at 3, 12, and 24 weeks of age, respectively. We observed that human avoidance and novel object approach behaviors are quasi inexistent in the group tested at 3 weeks, but are more and more present in the groups tested at subsequent ages. In a longitudinal study, we tested 48 foals successively at 3, 6, 12, and 24 weeks of age. Since reactions appear progressively with time, no stability over time or across situations was found. However, once a foal manifests a behavioral reaction at a given age, it will always reproduce this reaction subsequently.

Ethical stockmanship

The objective of this review is to consider the ethics of stockmanship, particularly from the perspective of the nature and extent of the duties of stockpeople to their farm animals. It will consider what science tells us about the impact of stockmanship on the animal, particularly the welfare of the farm animal. The effects of human-animal interactions on the stockperson will also be considered, since these interactions affect the work performance and job satisfaction of the stockperson and thus indirectly affect animal welfare. Animal ethics is broader than animal welfare and includes economic as well as philosophical, social, cultural and religious aspects. This paper is predicated on the view that farm animals can suffer, and that animal suffering is a key consideration in our moral obligations to animals. Housing and husbandry practices affect farm animal welfare and thus farmers and stockpeople have a responsibility to provide, at minimum, community-acceptable animal housing and husbandry standards for their animals. The farmer's or stockperson's attitudes and behaviour can directly affect the animal's welfare and thus they also have a responsibility to provide specific standards of stockmanship for these animals. However, research suggests that the behaviour of some stockpeople is not as correct as it might be. Such situations exemplify the inevitably unequal human - domestic animal relationship, and this inequality should be considered in analysing the boundary between right and wrong behaviour of humans. Thus ethical discussion, using science and other considerations and involving stockpeople, livestock industries, government and the general public, should be used to establish and assure acceptable stockperson competencies across the livestock industries. Training programs targeting the key attitudes and behaviour of stockpeople presently offer the livestock industries good opportunities to improve human-animal interactions.

Use of non-human biobehavioral models in critical care nursing research

The complexity of critical care settings and diversity among vulnerable patient populations often make clinical research study outcomes difficult to evaluate. When interventions are tested, outcomes or improvements in condition often can be questioned on the basis of variations in the patient's constitutional, genetic, or disease state. Study of mechanisms underlying physiologic problems in the seriously ill also are complicated by effects of drugs, preexisting cellular damage, and behavioral influences. Animal models are used increasingly in nursing science to study clinical problems and care approaches when there is need to ensure experimental control and provide consistency across subjects. The competent clinical investigator who decides to choose this option is advised to seek training in animal care, work with skilled colleagues in the basic sciences, and use excellent consultants. Several considerations arise when choosing a non-human alternative for biobehavioral research. First, there must be a compelling reason to choose this model, not simply for convenience or novelty. Second, the investigation should be humane, well planned, and well supported. Animal studies are not necessarily more economical than those involving humans, and they require serious ethical and scientific consideration to justify their use. When these conditions are met, the use of non-human models often can clarify a biobehavioral mechanism or biophysical response that will contribute significantly to nursing science.

Human factors affecting the behaviour and productivity of commercial broiler chickens

1. The purpose of this study was to examine the relationship between stockperson attitude and behaviour; bird behaviour and productivity in the chicken meat industry. 2. No relationship between stockperson attitude and behaviour was observed, which is in contrast to studies in the pig and dairy industries. 3. Evidence is provided for the existence of sequential relationships between stockperson behaviour, bird fear levels and productivity in the broiler farms examined. 4. The mechanism(s) responsible for the negative relationships between fear levels and production is unclear. It is hypothesised that chronic stress or a series of acute stress responses may be the mechanism through which fear affects productivity. 5. The relationship between human behaviour, bird fear levels and productivity indicates the potential that exists to improve productivity and perhaps welfare of commercial broilers by reducing fear levels in broiler chickens.

Behavioural response to humans and the productivity of commercial dairy cows

This study examined the relationships between the attitude and the behaviour of the stockperson towards cows and the behavioural response to humans and the milk production of cows at 31 commercial dairy farms over one lactation. The attitude of the stockperson was measured on the basis of the stockperson's opinion of the cow's behaviour and how the stockperson evaluated his own behaviour. The behaviour of the stockperson was measured by recording the nature and frequency of the tactile interactions and some visual and auditory interactions directed towards the cows. The behavioural response of cows to humans was assessed by observing their approach behaviour to an unfamiliar experimenter in a standard test and production records were collected for the entire lactation at each farm. Correlation and regression analyses using farm averages were used to examine relationships between human and cow variables. Several cow behaviour variables, indicative of fear of humans, were moderately (P<0.05) to highly (P<0.01) correlated with milk yield and composition and regression analysis indicated that fear of humans accounted for 19% of the variation in milk yield between farms. The results suggest that at farms where milk yield was low, cows showed less approach to the experimenter in the standard fear test than at farms where milk yield was higher. A composite attitude score, based on the responses of stockpeople to questions about patting and talking to cows, ease of movement of cows and cows recognising unfamiliar stockpeople, was moderately (P<0.05) to highly (P<0.01) correlated with the behaviour of the stockperson. While a number of stockperson behaviour variables were correlated (P<0.05) with milk yield, the former variables were generally poorly correlated with cow behaviour. Therefore these preliminary findings provide evidence that, as seen in the pig industry, sequential relationships may exist between the attitude and behaviour of the stockperson and the behaviour and productivity of commercial dairy cows. Research is required to further examine these relationships because of the possible implications on cow productivity and welfare.