Early human contact and housing for pigs - part 1: responses to humans, novelty and isolation

The development of fear and stress responses in animals can be influenced by early life experiences, including interactions with humans, maternal care, and the physical surroundings. This paper is the first of three reporting on a large experiment examining the effects of the early housing environment and early positive human contact on stress resilience in pigs. This first paper reports on the responses of pigs to humans, novelty, and social isolation. Using a 2 × 2 factorial design, 48 litters of pigs were reared in either a conventional farrowing crate (FC) where the sow was confined or a loose farrowing pen (LP; PigSAFE pen) which was larger, more physically complex and allowed the sow to move freely throughout the farrowing and lactation period. Piglets were provided with either routine contact from stockpeople (C), or routine contact plus regular opportunities for positive human contact (+HC) involving 5 min of scratching, patting and stroking imposed to the litter 5 days/week from 0-4 weeks of age. The positive handling treatment was highly effective in reducing piglets' fear of humans, based on +HC piglets showing greater approach and less avoidance of an unfamiliar person at 3 weeks of age. There was evidence that this reduction in fear of humans lasted well beyond when the treatment was applied (lactation), with +HC pigs showing greater approach and less avoidance of humans in tests at 6, 9 and 14 weeks of age. The +HC treatment also reduced piglets' fear of a novel object at 3 weeks of age, and for pigs in FC, the cortisol response after social isolation at 7 weeks of age. Rearing in FC compared to LP reduced piglets' fear of novelty at 3 weeks of age, as well as their vocalisations and cortisol response to isolation at 7 weeks of age. The FC pigs showed greater approach and less avoidance of humans compared to LP pigs at 3, 4 and 6 weeks of age, but not at 9 and 14 weeks of age. These results show that positive handling early in life can reduce pigs' fear of humans, fear of novelty and physiological stress response to social isolation. The LP pigs were reared in a more isolated environment with less overall contact with stockpeople and other pigs, which may have increased their fear responses to humans and novel situations, suggesting that different housing systems can modulate these pigs' responses.

Training of transport drivers improves their handling of pigs during loading for transport to slaughter

Pig transport drivers' (TDs') handling actions are of great importance as these drivers handle a large number of finishing pigs during stressful situations. Poor handling techniques can have negative consequences for working conditions, pig welfare and meat quality. We studied the effects of a training intervention on Swedish TDs' attitudes towards pigs and their handling actions during loading for transport to slaughter. Twenty TDs working with commercial pig transportation in Sweden were recruited and completed an attitude questionnaire. Ten of them were observed during one loading of pigs before training, and one or two loadings after training (49-265 pigs per loading), and eight of them completed the attitude questionnaire again 50-160 days after training. The cognitive-behavioural training program ProHand Pigs® was adapted and delivered to the ten TDs during a group session, followed by individual meetings. TDs' handling actions were video recorded and summarised as binary variables per 5-s interval. Factor analysis, principal component analysis and paired t-test were conducted to investigate the effects of the training intervention on TDs' attitudes, and mixed-effects logistic models were used to examine effects on negative and positive handling actions. Training tended to decrease TDs' beliefs that it is important to move pigs quickly (P = 0.095). Training decreased the odds of a 'moderately to strongly negative' action by 55% (P = 0.0013) and increased the odds of a 'positive' action by 97% (P < 0.0001). This study provides valuable insights into the possibilities to improve TDs' handling actions, and implications for pig welfare during slaughter transport. The study supports previous findings that the attitudes and behaviour of handlers can be improved by cognitive-behavioural training. While our previous research has shown reciprocal relationships between TDs' actions and pig behaviour, further research on TDs' attitudes towards handling that underlie the nature of their behaviour when handling pigs is necessary to fine-tune the cognitive-behavioural training program applied in the present study.

Research note: Expert opinions of feather sucking and licking behavior in meat chicken breeder birds

Feather sucking, or feather licking, has been reported anecdotally by employees in the Australian meat chicken breeder industry, but scarcely in the scientific literature. Consequently, the causes and implications of this behavior in meat chicken breeding chickens is relatively unknown. We surveyed 17 industry experts to generate hypotheses about feather sucking behavior. We aimed to understand the frequency and when it occurs, and attempted to understand what may cause an "outbreak". The recruitment of participants was intentionally biased towards Australian perspectives; only 5 of the 17 participants were international. All participants, except 1, had seen feather sucking/licking behavior (94.1%) and most participants (80%) suggested that the behavior was most frequently observed during rearing. Participants presented varying concerns about this behavior, ranging from the perspective that it was "normal" and had no impact on welfare, to concerns about mating injuries due to damaged feathers, increased risk of feather pecking and cannibalism, and psychological stress indicated by expression of repetitive (seemingly) functionless behavior. "Feather licking," "feather sucking," "feather eating," and "feather pecking" were terms used interchangeably, leading to confusion by participants about the cause and implications of the target behavior. The most common factors reported as the cause were boredom (52.9%), nutritional deficiencies (47.1%), and feed restriction (41.2%) and more than 80% of respondents agreed that stress contributes to feather sucking. The outputs from this study reflect only a small, but expert, number of opinions on feather sucking/licking behaviors in the Australian meat chicken breeder industry. A systematic understanding of this behavior is needed to provide insight into causation and the implications for welfare.

Descriptive epidemiology of smothering in Australian commercial free-range layer hen farms

Since the early 2000 s the practice of free-range egg production has increased in developed countries, partly driven by consumer perception that free-range housing is better for hen welfare. While poultry in free-range systems have more behavioural opportunities compared with poultry in caged systems, free-range systems are associated with greater frequencies of infectious disease, predation and 'smothering', a condition where birds pile on top of one another with death occurring due to suffocation. Although the frequency of smothering deaths in Australian free-range layer poultry is anecdotally high, there is a lack of empirical evidence quantifying smothering cause-specific mortality rates and identifying factors that place birds at higher risk of death from smothering. This was a prospective cohort study of poultry flocks managed by three commercial free-range layer organisations in Eastern Australia. Flocks were enrolled into the study from 1 January 2019 to 29 March 2021 and were followed until the end of lay or until the end of the study on 31 March 2022, whichever occurred first. Throughout the follow-up period flock managers provided production details for each flock and details of smothering events using custom-designed logbooks.A total of 84 flocks were enrolled in the study: 32 from Organisation 1, 35 from Organisation 2 and 17 from Organisation 3. The number of birds per flock ranged from 16,000 to 45,000. The total mortality rate was 1131 deaths per 10,000 bird-years. Smothering mortality rate across the three organisations was 183 (minimum 133, maximum 223) deaths per 10,000 bird-years at risk. Smothering accounted for around 16% (minimum 9%, maximum 22%) of all deaths.We identified no distinctive temporal pattern in daily smothering risk as a function of either the number of days since placement or calendar date. The locations of smothering events in sheds and in the outdoor range were not consistent, with relatively large numbers of smothering events occurring in specific locations for some sheds but not others. To the best of our knowledge, this study is the largest prospective study of smothering mortality in commercial free-range layer flocks conducted to date. Estimates of smothering incidence rate and how that varies within and between flocks and organisations over time provides a critically important benchmark for further investigations into this substantial area of productivity loss.

Review: Early life piglet experiences and impacts on immediate and longer-term adaptability

Pigs in production systems are routinely exposed to challenging situations including abrupt weaning, painful husbandry procedures, intense contact with stockpeople, and exposure to novel social and physical environments. The resilience of pigs to these stressors has implications for animal welfare and productivity and can be affected by early life experiences. In rodents and primates, early experiences with stressors that the animal can adequately cope with confers future stress adaptability, leading to less abnormal behaviour, lower behavioural and physiological responses to stressors, and faster recovery after stress exposure. Early experiences that can affect the ability of pigs to overcome challenge include interactions with the dam, conspecifics, humans, and the overall complexity of the environment. Farrowing crates limit the sow's ability to show maternal behaviour towards piglets, and negatively affect piglet social behaviour during lactation, with less play and more manipulation of pen mates in crates than in large pens. Rearing in pens has been proposed to improve the ability of pigs to cope with routine stressors, but the evidence for this is conflicting. The early housing environment can affect general fearfulness and fear of humans, and surprisingly, most studies have shown fear responses to be greater in pigs reared pens than in crates. Given the potential for fear to affect animal welfare and productivity, more detailed research on early housing effects is needed. While there is limited evidence that early housing influences fear in the longer term, human contact early in life appears to have a more profound and sustained effect, with regular positive human interaction early in life having an enduring effect on reducing pigs' fear of humans. The practicality of positive human-pig interaction in a commercial environment needs to be examined further, but only a small amount of positive human contact early in life can improve the resilience of pigs to routine husbandry stressors. Early social experience with non-littermates reduces stress at weaning and mixing, while early weaning before 3-4 weeks of age increases abnormal behaviours. Environmental enrichment, such as foraging substrates and increased floor space, reduces abnormal behaviour in piglets, but housing in an enriched environment early in life and subsequently in a non-enriched environment can increase abnormal behaviour if these environments are dramatically different. Although the later environment can modify the influence of the early environment, overall, early life experiences can be important in shaping how pigs cope with stress in both an immediate and longer-term capacity.

Conceptualising dog owner motivations: The Pet Care Competency model and role of 'duty of care'

The current literature on the behaviour, health, and management of companion dogs (Canis lupus familiaris) indicates that their welfare is often compromised. While there are many factors that have the potential to influence the welfare of companion dogs, carer behaviour is highly influential. Therefore, in order to improve the welfare of companion dogs, it is vital to understand the general and specific human factors that underpin carer behaviour. One such factor that has received little attention in the scientific literature is duty of care. This paper will firstly review several extant, empirically validated models of human behaviour including the Cognitive Hierarchy model, the Schwartz Theory of Basic Human Values, the Theory of Planned Behaviour, and Hemsworth and Colemans Animal-Carer model. Secondly, by combining aspects of moral obligation and care, a strong theoretical argument will be presented for the role of duty of care as a fundamental motivational driver of animal-carer behaviour. Finally, by integrating duty of care with the aforementioned existing models, a hypothesised model of Pet Care Competency is presented, providing a more detailed representation of animal carer motivations than previously documented. Drawing together this wide range of behavioural research and psychological theory, the Pet Care Competency model provides a strong conceptual framework for future empirical investigation. Once the relevant values, beliefs, and attitudes that underpin duty of care and contribute most strongly to an individuals Pet Care Competency are identified, this model can be utilised to inform behaviour change programmes that aim to improve carer behaviour and, consequently, dog welfare. By employing this model to identify and target the key elements of carer motivation, a more enduring outcome may be achieved than traditional knowledge-based interventions. This work has the potential to significantly improve the outcomes of animal welfare education and intervention programmes, warranting further exploration.

The effects of floor space and nest box access on the physiology and behavior of caged laying hens

Confinement housing appears to be at the forefront of concern about laying hen welfare. This experiment examined the effects of floor space during rearing (315 or 945 cm2/bird) and adulthood (542 or 1648 cm2/bird) and access to a nest box on the welfare of caged laying hens. Measurements of the normality of biological functioning, such as plasma, egg albumen and yolk and fecal corticosterone concentrations, and heterophil to lymphocyte ratios, behavioral time budgets, mortality and efficiency of productivity, and measurement of hen preferences, such as choice behavior in Y maze tests, were used to assess hen welfare. There were no effects of treatment on physiological measurements. Hens given less space during adulthood spent less time mobile, inedible pecking, drinking, and preening and spent more time resting and feed pecking and sitting (P < 0.05). Hens with access to a nest box spent more time resting (P = 0.046) and less time sham dust bathing (P = 0.044) than hens without access to a nest box. There were no effects of space allowance on choice behavior for space or a nest box over food; however, hens with access to a nest box chose the nest box over food more than hens without access to a nest box (P = 0.0053). The present experiment provides no convincing evidence that either reducing space allowance in adulthood from 1648 to 542 cm2/bird or eliminating access to a nest box results in disruption of biological function. Less space and no access to a nest box did not increase the choice for more space or a nest box, respectively, over food in the preference tests. However, reduced floor space reduced behavioral freedom and denying access to a nest box eliminated the opportunity for the motivated behavior of laying their eggs in a discrete enclosed nest box, both of which presumably provide hens with the opportunity for positive affective experiences.

Why did severe feather pecking and cannibalism outbreaks occur? An unintended case study while investigating the effects of forage and stress on pullets during rearing

This 2 × 2 factorial experiment aimed to investigate the effects of stimulating foraging behavior from wk 6 and imposed stress at wk 16 on the development of severe feather pecking (SFP) in chickens reared for free-range egg production. Non-beak-trimmed ISA Brown chicks were purchased at one day old and floor-reared on wood shavings. From wk 6, straw was provided daily in dispensers (Forage vs. No forage) to stimulate foraging. At wk 15, there were 16 pens of 50 pullets. "Stressors" were applied to half the pens in wk 16 via combined transport, relocation, and mixing (TRM) of pullets, simulating activities around transfer from the rearing to egg-laying farm (TRM vs. Not TRM). Range access was permitted from wk 21. Behavior, plumage damage (PD), growth, egg production, feed use, injuries, and mortalities were recorded, along with litter moisture and pH. In wk 26, an SFP outbreak commenced. By wk 34, PD was worse in south- than north-aspect pens (P < 0.001). Further, PD was more affected by side of the shed than the experimental treatments. In wk 30, an outbreak of injurious pecking (IP) commenced in the 4 TRM-treatment pens on the south side, with IP deaths almost 3 times more common in the Forage+TRM than No forage+TRM treatment. We suggest factors associated with a 13-day rainfall event that occurred in late winter predisposed the flock to SFP. While multiple factors such as winter cold, muddy ranges, damp floor litter with elevated pH, among others coincided, hens were clearly more impacted in south- than north-aspect pens. Once initiated, SFP possibly spread via social learning, and by wk 40, ∼98% of hens had PD. Interestingly, the IP outbreak was related to a combination of factors (stressors?), such as being housed in colder, damper south-aspect pens (note: southern hemisphere), having added Forage, and TRM. These unexpected relationships could help direct future research to identify the specific factors involved in the causation of SFP and IP/cannibalism outbreaks.

Forming groups of aggressive sows based on a predictive test of aggression does not affect overall sow aggression or welfare

This experiment examined the effects of group composition on sow aggressive behaviour and welfare. Over 6 time replicates, 360 sows (parity 1-6) were mixed into groups (10 sows per pen, 1.8 m²/sow) composed of animals that were predicted to be aggressive (n = 18 pens) or groups composed of animals that were randomly selected (n = 18 pens). Predicted aggressive sows were selected based on a model-pig test that has been shown to be related to the aggressive behaviour of parity 2 sows when subsequently mixed in groups. Measurements were taken on aggression delivered post-mixing, and aggression delivered around feeding, fresh skin injuries and plasma cortisol concentrations at days 2 and 24 post-mixing. Live weight gain, litter size (born alive, total born, stillborn piglets), and farrowing rate were also recorded. Manipulating the group composition based on predicted sow aggressiveness had no effect (P > 0.05) on sow aggression delivered at mixing or around feeding, fresh injuries, cortisol, weight gain from day 2 to day 24, farrowing rate, or litter size. The lack of treatment effects in the present experiment could be attributed to (1) a failure of the model-pig test to predict aggression in older sows in groups, or (2) the dependence of the expression of the aggressive phenotype on factors such as social experience and characteristics (e.g., physical size and aggressive phenotype) of pen mates. This research draws attention to the intrinsic difficulties associated with predicting behaviour across contexts, particularly when the behaviour is highly dependent on interactions with conspecifics, and highlights the social complexities involved in the presentation of a behavioural phenotype.

Key determinants of pig welfare: implications of animal management and housing design on livestock welfare

The present review using the pig as a model has highlighted the importance of the design of the housing system on the welfare of farm animals. It has emphasised the need for research on animal welfare in new and modified housing systems, as well as current but contentious systems, to be attentive to the design contributions of these systems to animal welfare. The review has highlighted areas for future research to safeguard sow and piglet welfare, including the following: effective environmental enrichment for gestating sows in intensive, indoor and non-bedded systems; opportunities to increase foraging and feeding times in feed-restricted gestating sows; design features that allow both access to important resources, such as feed, water and a comfortable lying area, and escape opportunities to reduce aggression and minimise risks to the welfare of group-housed sows; and less confined farrowing and lactation systems. The review also shows that animal welfare problems may be less a function of the type of housing system than of how well it operates. The skills, knowledge and motivation of stockpeople to effectively care for and manage their animals are integral to the standard of welfare experienced by their animals. Attitudes influence not only the manner in which stockpeople handle animals, but also their motivation to care for their animals. Thus, training targeting technical skills and knowledge as well as the attitudes and behaviours of stockpeople should be a primary component of the human resource management practices at a farm. While public concerns and policy debates often focus on intensive housing systems, research indicates that the design and management of both indoor and outdoor housing systems is probably more important for animal welfare than is generally recognised.

Short communication: Milking order consistency of dairy cows in large Australian herds

We used on-farm records from dairy infrastructure to examine the consistency of the milking order over 150 d in 5 Australian dairy herds that were milking more than 500 cows as a single group. Within a single day the difference in milking order rank position was less than 20 percentage points for 72% of cows. The correlation coefficient comparing milking rank position in the morning and afternoon was 0.72, with the position of cows at the beginning and end of the milking order being more consistent than cows toward the middle of the milking order. Over a period of 150 d, cows with a mean position in the first and last 20% of the milking order maintained their position more consistently than cows in the middle of the milking order. Milking position of cows between one month and the next was highly correlated (r = 0.88). In large herds, subpopulations of cows are regularly milked toward the beginning and the end of the milking order. It is common for cows to be collected from the paddock as a group, to wait as a group in the dairy yard to be milked, and to return individually to the paddock or feed pad immediately after they have been milked. Thus, cows milked later in the milking order are likely to be away from the paddock for several hours longer than cows milked earlier in the milking order. This may affect their welfare though differences in time available for lying down, equality of pasture eaten, and time spent standing in the dairy yard.

The short-term behavioural response of sows, but not gilts, to a social stimulus is related to sow aggressiveness in groups

This study examined relationships between the behavioural response of pregnant gilts (n=200, gestation 1) and sows (n=200, gestation 2) to a live, similarly-aged female pig (unfamiliar pig test, UPT) and to a fibre-glass model pig (model pig test, MPT), and aggressive behaviour on the day after mixing (day 2). Sows with a short latency to make contact with an unfamiliar sow in the UPT were more likely to deliver high levels of aggression at day 2 of gestation 2 (P=0.005), but this relationship was stronger when a model pig was used (P<0.001). Similarly, sows with a long duration of tactile contact with the model pig in the MPT were more likely to deliver high levels of aggression at day 2 of gestation 2 (P=0.015), but this relationship was weaker than that between aggression and the latency to contact the model pig. When the terms the latency to contact the unfamiliar pig in the UPT and the model pig in the MPT, as well as the duration of contact with the model pig in the MPT, were included in an overall model of aggression at day 2 of gestation 2, behaviour towards the unfamiliar pig became not statistically significant (P>0.05). A strong relationship was not apparent with gilts (P>0.05). Thus, the socially inexperienced pig may not be an ideal model for sow behaviour. This study indicates that sows with a short latency to contact a model pig are more likely to be aggressive when mixed into groups.

Individual variation in sow aggressive behavior and its relationship with sow welfare

This study examined the relationships between individual sow aggressive behavior and sow welfare, based on aggression, skin injuries, and stress, in a total of 275 pregnant domestic sows. Over 4 time replicates, sows were randomly mixed into groups of 10 (floor space of 1.8 m/sow) within 7 d of insemination in both their first and second gestations (200 sows per gestation with 126 sows observed in both gestations). Measurements were taken on aggression (both delivered and received) at feeding, skin injuries, and plasma cortisol concentrations at d 2, 9, and 51 after mixing. Live weight gain, nonreproductive removals, litter size (born alive, total born, and stillborn piglets), and farrowing rate were also recorded. In both the first and the second gestations, sows were classified at d 2 after mixing as "submissive" (delivered little or no aggression at feeding relative to aggression received), "subdominant" (received more aggression at feeding than delivered), and "dominant" (delivered more aggression at feeding than received). In both gestations, sows classified as dominant at d 2 subsequently delivered more (gestation 1, < 0.01; gestation 2, < 0.01) and received less (gestation 1, < 0.01; gestation 2, < 0.01) aggression and gained the most weight (gestation 1, < 0.01; gestation 2, < 0.01). Dominant sows had the least skin injuries throughout gestation 1 ( = 0.04), and although submissive sows sustained the most skin injuries at d 9 and 51 of gestation 2, at d 2 the classifications did not differ in skin injuries ( < 0.01). Subdominant sows had the highest cortisol concentrations at d 2 of gestation 2, but there were no differences between classifications at d 9 and 51 in either gestation (gestation 1, > 0.05; gestation 2, = 0.02). There were no significant relationships between aggression classification and reproduction and nonreproductive removals ( > 0.05). In conclusion, sows classified as dominant at feeding at d 2 subsequently received less aggression at feeding, sustained fewer skin injuries, and had higher live weight gain. Submissive and subdominant sows in groups are likely to benefit from the provision of increased resources such as space and access to feed.

Effects of group housing on sow welfare: a review

Factors that have been shown to impact the welfare of group-housed sows are discussed in this review. Floor space allowance markedly affects sow welfare. In addition to quantity of floor space, the quality of space is important: spatial separation between sows can be provided with visual or physical barriers and stalls. Whereas 1.4 m/sow is insufficient, further research is required to examine space effects in the range of 1.8 to 2.4 m/sow in more detail. The period immediately after mixing has the most pronounced effects on aggression and stress, and therefore, well-designed mixing pens offer the opportunity to reduce aggression, injury, and stress while allowing the social hierarchy to quickly form. Because hunger is likely to lead to competition for feed or access to feeding areas, strategies to reduce hunger between meals through higher feeding levels, dietary fiber, or foraging substrate should be examined. However, feeding systems, such as full-body feeding stalls, can also affect aggression and stress by providing protection at feeding, but deriving conclusions on this topic is difficult because research directly comparing floor feeding, feeding stalls, and electronic sow feeder systems has not been conducted. Familiar sows engage in less aggression, so mixing sows that have been housed together in the previous gestation may reduce aggression. Although there is evidence in other species that early experience may affect social skills later in life, there are few studies on the effects of early "socialization" on aggressive behavior of adult sows. Genetic selection has the potential to reduce aggression, and therefore, continued research on the opportunity to genetically select against aggressiveness and its broader implications is required. Most research to date has examined mixing sows after insemination and knowledge on grouping after weaning is limited.

The effects of environmental enrichment and beak-trimming during the rearing period on subsequent feather damage due to feather-pecking in laying hens

This experiment investigated effects of environmental enrichment and beak-trimming during the rearing period on behavior in rearing and plumage damage later in life. Treatments were applied in a 2 × 2 factorial arrangement. Half of the birds were beak-trimmed at 1 d of age using an infra-red laser. A follow-up light-trim was performed at 11 wk of age with a hot blade. Environmental enrichment consisted of pecking strings, whole oats in the litter, and greater litter depth. Sixteen pens of 50 ISA Brown laying hens were used. Four pullets were selected from each pen as focal birds and observed in their home pens between 3 and 14 wk of age. Plumage damage was scored at the end of the experiment in wk 43. Beak-trimmed birds performed less ground-pecking (P = 0.003), less severe feather-pecking (P = 0.021) and more gentle feather-pecking (P = 0.018) than their non-trimmed counterparts during the rearing period. These birds also exhibited less feather damage in wk 43 (P < 0.001). The results indicate that gentle feather-pecking during rearing is not related to plumage damage when older. Additionally, higher rates of ground-pecking and severe feather-pecking during rearing may be predictive of plumage damage later in life. There was no effect of enrichment on plumage damage. It was concluded that while there was no effect on enrichment, beak-trimming appeared to be effective in reducing plumage damage in wk 43.

Relationship between plasma and tissue corticosterone in laying hens (Gallus gallus domesticus): implications for stress physiology and animal welfare

This study directly compared the dynamics of change in plasma corticosterone concentration with the dynamics of change in tissue corticosterone concentration in laying hens. In concert, we measured the rate of gluconeogenesis, glycogenesis, and glycolysis in the liver, kidney, skeletal muscle, and heart. We evaluated these changes acutely, over 3 h in response to an adrenocorticotropic hormone (ACTH) injection, and chronically, over 24 h in response to food and water deprivation. In response to ACTH injection, there was a significant (P < 0.05) increase in plasma corticosterone concentration and a parallel significant increase in corticosterone concentration in the skeletal muscle, kidney, and heart. However, the change in corticosterone concentration in the liver did not parallel the plasma, at times it was greater than the plasma, and there was a second significant increase (P < 0.05) in corticosterone concentration in the liver after 180 min. Under these conditions, the rate of gluconeogenesis in the liver decreased and the rate of glycogenesis increased. In contrast, after 12 h and 24 h of food and water deprivation plasma corticosterone concentration was increased, and this was paralleled by increased corticosterone concentration in the liver, an increase in the rate of gluconeogenesis and a decrease in the rate of glycogenesis. After ACTH injection, glucose concentration in the liver was not significantly depleted but after 12 h or 24 h of food and water deprivation it was significantly depleted (P < 0.05). Plasma corticosterone concentration provided different insight into the effect of the stressor on hen physiology under acute and chronic conditions. Our data suggest that extending our evaluation of stress to the site of corticosterone action, that is, the target tissue, may enhance our ability to evaluate stress and the welfare of laying hens.

A scientific comment on the welfare of domesticated ruminants slaughtered without stunning

This review provides a scientific comment on the welfare of ruminants slaughtered by ventral-neck incision without stunning. Evidence is derived from studies of calves, sheep and goats. Reference is also made to findings in other mammals including humans. Pain is an inherently subjective experience and only indirect indices are available in animals. Neurophysiological tools are widely used in humans to assess pain and have demonstrated that electroencephalographic (EEG) variables correlate well with subjective evaluations of pain. These neurophysiological tools have also been applied in animal studies. In humans pain is associated with major cutting injuries and it is widely accepted that farm animals also experience pain due to such injuries. Overwhelming international scientific opinion has long been that slaughter by neck incision of conscious animals causes pain. A series of studies in calves demonstrated that slaughter by ventral-neck incision is likely to be perceived as painful. It is proposed that, as in cattle, non-stunned sheep and goats would experience pain in a similar manner. The precise assessment of the point after slaughter at which non-stunned animals become insensible remains a major methodological challenge. In sheep it is at least 2-8 seconds, but may be 8-20 seconds in duration. In cattle the mean duration is similar, but can commonly be extended to longer than 60 seconds with occasional instances of even greater durations. Taken together, these findings indicate that because the slaughter of cattle, sheep and goats by ventral-neck incision without prior stunning is likely to cause pain, this poses a risk to animal welfare.

Scientific assessment of animal welfare

Animal welfare is a state within the animal and a scientific perspective provides methodologies for evidence-based assessment of an animal's welfare. A simplistic definition of animal welfare might be how the animal feels now. Affective experiences including emotions, are subjective states so cannot be measured directly in animals, but there are informative indirect physiological and behavioural indices that can be cautiously used to interpret such experiences. This review enunciates several key science-based frameworks for understanding animal welfare. The biological functioning and affective state frameworks were initially seen as competing, but a recent more unified approach is that biological functioning is taken to include affective experiences and affective experiences are recognised as products of biological functioning, and knowledge of the dynamic interactions between the two is considered to be fundamental to managing and improving animal welfare. The value of these two frameworks in understanding the welfare of group-housed sows is reviewed. The majority of studies of the welfare of group-housed sows have employed the biological functioning framework to infer compromised sow welfare, on the basis that suboptimal biological functioning accompanies negative affective states such as sow hunger, pain, fear, helplessness, frustration and anger. Group housing facilitates social living, but group housing of gestating sows raises different welfare considerations to stall housing, such as high levels of aggression, injuries and stress, at least for several days after mixing, as well as subordinate sows being underfed due to competition at feeding. This paper highlights the challenges and potential opportunities for the continued improvement in sow management through well-focused research and multidisciplinary assessment of animal welfare. In future the management of sentient animals will require the promotion of positive affective experiences in animals and this is likely to be a major focus for animal welfare science activity in the early twenty-first century.

Training to improve stockperson beliefs and behaviour towards livestock enhances welfare and productivity

The principle that supervising and managing animals affects farm animal welfare is widely recognised within the livestock industries. However,the manner in which the stockperson affects animal welfare, both directly and indirectly, is probably not fully appreciated. Together with the opportunity to perform their tasks well, stockpeople require a range of well-developed husbandry skills and knowledge to effectively care for and manage farm animals. There are three main factors that can be considered to contribute to a stockperson's work performance: capacity, willingness and opportunity. Capacity includes variables such as skills, health, ability and knowledge, while willingness includes motivation, job satisfaction, attitude to the animals and work attitude, and opportunity includes working conditions, actions of co-workers and organisational policies and rules. This paper briefly reviews the influence of the stockperson on livestock welfare and productivity and the opportunities to improve the stockperson's performance through training. It is clear that there is a continuing need for livestock industries to train their personnel to effectively care for and handle their stock. Underestimating the role and impact of the stockperson will seriously risk the welfare and productivity of livestock. Indeed, the stockperson may be the most influential factor affecting animal handling, welfare and productivity. Furthermore, it is likely that, in the near future, both the livestock industries and the general community will place an increasing emphasis on ensuring the competency of stockpeople to manage the welfare of livestock.

Examining the usefulness of a Y-maze choice method to measure the preferences of laying hens

Measurement of animal preferences can be used as an indirect, but persuasive, method for assessing animal welfare on the basis that preferences may identify resources and behaviours that might be important to animals. The present experiment examined the usefulness of a Y-maze methodology, incorporating alteration of motivational state through prior restriction of resources of potentially differing value in assessing and understanding animal preferences. The choice behaviour of laying hens for feed, a dustbath substrate (sawdust; ‘dust’) and social contact was measured under three pairwise comparisons in a Y-maze apparatus. In each of the three experiments, 48 birds (HyLine Brown Strain; n = 24 per experiment) were offered a choice of two resources in a Y-maze test, with one of the three possible resource pairings. In each experiment, after Y-maze training, an equal number of birds was deprived in a factorial design of Resource 1, Resource 2, both, or neither resource. Analysis of choices over 24 trials per bird in each experiment revealed that birds preferred feed over social contact or dust, irrespective of restriction of any of these resources, and further, were quicker (P < 0.01) to make feed choices than dust or social-contact choices. In the social contact and dust comparison, restriction of dust significantly (P < 0.05) increased choice for dust in the 24 trials (38 vs 53% dust choice), suggesting that dust restriction increased the birds’ motivation to access dust. This result potentially highlights the impact of the resource of comparison in pairwise tests on overall choice response to restriction. The inclusion of measurements of speed of movement through the Y maze proved a useful aspect of the methodology, providing results consistent with choice behaviour in all three experiments. Although overall choices for dust and social contact were not significantly (P = 0.328) different from random, birds were quicker (P < 0.05) to make dust choices than social-contact choices, suggesting that speed of choice may be a particularly sensitive correlate of current motivation levels. The consistency of results across these experiments, together with results reported in the literature on laying-hen preferences, suggests that the methodology is a promising option for assessing the relative preference for resources for laying hens. Additional evidence, particularly on the occurrence of abnormal behaviour, stress physiology and health, when restricted of the resource of interest is necessary to provide a more comprehensive assessment of the impact of the restriction on animal welfare.

Close human presence reduces avoidance behaviour in commercial caged laying hens to an approaching human

The quality of human contact that hens are exposed to will determine the degree of fear of humans that they experience. This has consequences for the welfare of commercial laying hens, as hens that are afraid of humans will be regularly exposed to a fear-provoking stressor. Hens can be habituated to human presence using positive or neutral human–animal interactions, although the specific human behaviours that are considered positive or neutral by the hens are still being determined. This experiment investigated whether the proximity or duration of visual contact with a human affected fear of humans in commercial caged laying hens (n = 216). Commercial laying hens were exposed to daily visual human contact at one of three proximities (0, 0.75 or 1.50 m) and one of three durations (2, 30 or 90 s) in a 3 by 3 factorial design for a period of 28 days. Avoidance behaviour was assessed on Days –5, 15 and 30, and the plasma corticosterone response to handling was assessed on Days –5 and Day 30. Visual contact with a stationary human at close proximity (0 m) significantly (P = 0.03) reduced the avoidance response of commercial laying hens to an approaching human, although there was no clear effect of proximity on corticosterone response to handling. The duration of human contact had no effect on avoidance behaviour or corticosterone response. Stockpeople may consider working more closely to the cages in a non-threatening manner to reduce fear of humans in their flock.

Behavioural responses of lambs to plastic clips as an alternative procedure to mulesing

OBJECTIVE

Compare the effects on the behaviour of lambs of applying occlusive plastic clips, as an alternative procedure to surgical mulesing, with tail docking, surgical mulesing and a control treatment.

PROCEDURE

We allocated 48 6-7-week-old Merino lambs to four treatment groups: plastic clips (Clip); surgical mulesing (Mules); tail docking with a rubber ring (Tail ring); no treatment (Control). For each posture and behaviour observed on each of the 4 days post-treatment, a Dunnett's multiple comparison test was used to simultaneously compare the Clip treatment with each of the comparator treatments (Control, Tail ring and Mules treatments).

RESULTS

Most of the significant differences (P < 0.05) detected between the comparator treatments occurred on day 1. For four of these measurements, the Clip treatment differed (P < 0.01) from the Mules treatment, but from not the Control and Tail ring treatments: the Clip lambs spent less time standing immobile not interacting with ground, hay or feeder, less time standing immobile head down not interacting with ground, hay or feeder, more time walking and more time interacting with ground, hay or feeder.

CONCLUSION

These behavioural results, together with previous behavioural and physiological research, indicate that the effect on lamb welfare of applying occlusive clips is less than that of surgical mulesing.

Acute and chronic stress-like levels of cortisol inhibit the oestradiol stimulus to induce sexual receptivity but have no effect on sexual attractivity or proceptivity in female sheep

Stress-like levels of cortisol inhibit sexual receptivity in ewes but the mechanism of this action is not understood. One possibility is that cortisol interferes with the actions of oestradiol to induce sexual receptivity. We tested this hypothesis in 2 experiments with ovariectomised ewes that were artificially induced into oestrus by 12 days of i.m. injections of progesterone followed by an i.m. injection of oestradiol benzoate (ODB) 48 h later. In Experiment 1, ewes were randomly allocated to the following groups: saline infusion+25 μg ODB, saline infusion+50 μg ODB, cortisol infusion+25 μg ODB or cortisol infusion+50 μg ODB (n=5 per group). Saline or cortisol was infused i.v. for 40 h beginning at the ODB injection. In Experiment 2, ewes were infused with saline or cortisol (n=5 per group) for 5h beginning 1h before ODB injection. In both experiments, ewe sexual behaviour (attractivity, proceptivity and receptivity) was quantified every 6h. Blood samples were also collected. The cortisol infusion yielded plasma concentrations of cortisol similar to those seen during psychosocial stress. In both experiments, cortisol suppressed receptivity index (number of immobilisations by ewe/courtship displays by ram) and the number of times ewes were mounted but had no effect on attractivity or proceptivity, irrespective of the dose of ODB (Experiment 1). Cortisol also suppressed LH pulse amplitude. These results suggest that both an acute (5h) and chronic (40 h) infusion of cortisol inhibit oestradiol-induced sexual receptivity in ewes and that increasing the dose of ODB does not overcome the inhibitory effects of cortisol.

Immunisation against gonadotrophin-releasing hormone (GnRH) increases growth and reduces variability in group-housed boars

It is generally accepted that entire boars are leaner and more efficient than barrows but that they have poorer meat quality with an increased risk of boar taint. An additional issue in producing boars to meet market specifications is variation in growth performance, which may be exacerbated by high levels of aggression and mounting behaviour in group-housed animals. Immunisation against gonadotrophin-releasing hormone (GnRH), leading to immunological castration, offers a means of reducing aggression and mounting behaviour while maintaining most of the production efficiencies associated with entire boars. A total of 120 control boars, 120 immunised boars and 60 barrows (physically castrated at 5 days of age) were used in a study conducted in two replicates. Each replicate consisted of two pens each of boars, immunised boars and barrows, each pen containing 15 pigs, and two blocks of 15 individually-housed boars and immunised boars. The group-housed pigs had access to two single place electronic feeders per pen. Immunised boars were given the anti-GnRH vaccine (Improvac) at 14 and 18 weeks of age. In the 2 weeks immediately after the secondary immunisation at 18 weeks, average daily gain was greater in the immunised boars than the boars or barrows, particularly in those that were group housed, as indicated by the interaction (P = 0.035). From 18 to 23 weeks of age average daily gain was greater (P = 0.005) in immunised boars than in control boars and barrows and was greater (P < 0.001) in individually- than in group-housed pigs. The average daily gain of group-housed immunised boars and individually-housed control boars were similar over the 5-week period after secondary immunisation (1090 vs 1099 g/day), being ~20 and 15% higher than the group-housed control boars and barrows, respectively. The average daily feed intake was greater (P = 0.011) in immunised boars than in control boars with barrows intermediate. The standard deviation of bodyweight increased with age but was lower (P from 0.032 to 0.09) in immunised boars than in control boars and barrows between 18 and 22 and 17 and 21 weeks of age. Carcass fighting damage and pork pH were higher (P < 0.05) for control boars than for immunised boars or barrows. In conclusion, immunisation against GnRH increased average daily gain and average daily feed intake while decreasing variation in bodyweight and improving carcass and pork quality.

Effects of stall dimensions on the welfare of pregnant sows

The welfare of sows in gestation accommodation, and in particular the use of gestation stalls, is a major issue of concern among the animal-welfare community and pig producers. The objective of the present experiment was to investigate the effects of width (0.6 m v. 0.75 m) and length (2.0 m v. 2.2 m v. 2.4 m) of gestation stalls, plus a tether-stall negative-control treatment, on sow welfare measured via parameters of behaviour, stress physiology, immunology and gait score. The research involved 56 multiparous sows, housed alongside 56 non-experimental sows that were included to facilitate measurement of social behaviour. Posture and social behaviour were recorded after 7 weeks in treatment and animals were surgically catheterised in Week 8 for blood sampling, to measure daytime profiles of cortisol concentrations and responses to an adrenocorticotropic hormone (ACTH) challenge. The cell-mediated immune response to a bean extract was examined in Week 9. Sows spent more time standing during 2 h in the morning in 0.75-m- than 0.6-m-wide stalls (P < 0.05). This effect was greatest in 2.0-m-long stalls. Although the angle of head turn by sows was greater in 0.75-m- than 0.6-m-wide stalls (P < 0.001), social interactions were unaffected by stall dimensions. Sows in 0.6-m-wide stalls had lower total (P < 0.01) and free (P < 0.001) cortisol concentrations, reduced responsiveness to ACTH (P < 0.05) and increased immunoresponsiveness (P < 0.05) than did the sows housed in 0.75-m-wide stalls. There was no effect of stall length on total cortisol concentrations; however, free cortisol concentrations were greater in 2.4-m than in both 2.0- and 2.2-m treatments (P < 0.05). Sows in 2.2-m-long stalls showed significantly lower responsiveness to ACTH (P < 0.01), and greater immunoresponsiveness (P < 0.05) than did the sows in 2.0- and 2.4-m-long stalls. There were no interactions between stall width and length. The results indicated lower stress responses in both 0.6-m-wide and to some extent in 2.2-m-long stalls. Although these effects are not intuitively obvious, it is suggested that within the stall dimensions studied, 0.6 m × 2.2 m stalls will minimise stress effects. The opportunity was taken in the present experiment to test the scientific validity of these welfare measures by examining how well the measures predict the welfare status of the animal. Tethers and stalls are expected to provide variation in the welfare status of sows due to variation in the level of restriction and it was found that for four of the six biological variables (basal free and total cortisol concentrations, cortisol response following ACTH injection and deteriorated gait), expected differences were detected for sows housed in stalls (0.6-m width, 2.0-m length) and tethers.

Behavioural and physiological responses of laying hens to humans

Human interactions, particularly negative ones, affect the behaviour and physiology of laying hens, with possible implications for bird productivity and welfare. The present experiment investigated the effects of handling on the behaviour and plasma corticosterone concentrations of laying hens. A 2 × 2 × 3 factorial design was used to study the following three main effects: human contact during rearing [an additional 12 min of human contact per day (AC) or no additional contact (MC) during rearing]; handling quality in adulthood [brief daily exposure to positive (+ve) or negative (–ve) visual contact with a human]; and handling proximity in adulthood [handling-quality treatment (+ve or –ve) imposed at the following three distances from the birds: Near, 0–45 cm; Middle, 45–75 cm, or Far, 75–105 cm]. AC during rearing resulted in reduced avoidance behaviour of humans during adulthood, whereas handling imposed at the Far level resulted in greater avoidance behaviour than did handling at the Near or Middle level. The quality of the handling (+ve or –ve) had little effect on avoidance behaviour; however, there was a trend (P = 0.07) for hens receiving +ve handling to have a lower corticosterone response to human contact than those receiving –ve handling. These results demonstrate that visual human contact can influence the avoidance behaviour of laying hens.

The effect of breed, time spent with dam and late pregnancy induction of parturition on behavioural development in dairy calves

Three experiments examined the impact of breed, time spent with dam (TWD), gender, and late pregnancy induction of parturition and caesarean on the behavioural and heart rate responses of dairy calves at 2 and 6 weeks of age to Open field, Novel object and Startle tests and a Learning task. In Experiment 1 with male Jersey, Friesian and Friesian x Angus calves, there were some significant breed effects on responses to the Open field and the Novel object tests; Jersey calves appeared more curious and less fearful than Friesian x Angus calves. In Experiment 2, in which male and female Friesian calves were removed from their dams either between 0 and 12h or 12 and 24h after birth, there were no significant effects of gender or TWD. In Experiment 3, which studied the effect of induction of parturition using a long-acting glucocorticoid combined with short-acting progesterone 10 days prior to due calving date, there were no significant effects of late pregnancy induction of parturition. Across all three experiments, age at testing was the main factor influencing the responses of the calves. However, a number of interactions suggest that gender, time spent with dam and late pregnancy induction of parturition modified some of the responses to the tests as the calves developed.

Psychosocial stress suppresses attractivity, proceptivity and pulsatile LH secretion in the ewe

Various stressors suppress pulsatile secretion of luteinizing hormone (LH) in ewes and cortisol has been shown to be a mediator of this effect under various conditions. In contrast, little is known about the impact of stress and cortisol on sexual behavior in the ewe. Therefore, we tested the hypothesis that both psychosocial stress and stress-like levels of cortisol will reduce the level of attractivity, proceptivity and receptivity in addition to suppressing LH secretion in the ewe. In Experiment 1, a layered stress paradigm of psychosocial stress was used, consisting of isolation for 4 h with the addition of restraint, blindfold and noise of a barking dog (predator stress) at hourly intervals. This stress paradigm reduced LH pulse amplitude in ovariectomized ewes. In Experiment 2, ovariectomized ewes were artificially induced into estrus with progesterone and estradiol benzoate treatment and the layered stress paradigm was applied. LH was measured and sexual behavior was assessed using T-mazes and mating tests. Stress reduced pulsatile LH secretion, and also reduced attractivity and proceptivity of ewes but had no effect on receptivity. In Experiment 3, ewes artificially induced into estrus were infused with cortisol for 30 h. Cortisol elevated circulating plasma concentrations of cortisol, delayed the onset of estrus and resulted in increased circling behavior of ewes (i.e. moderate avoidance) during estrus and increased investigation and courtship from rams. There was no effect of cortisol on attractivity, proceptivity or receptivity during estrus. We conclude that psychosocial stress inhibits LH secretion, the ability of ewes to attract rams (attractivity) and the motivation of ewes to seek rams and initiate mating (proceptivity), but cortisol is unlikely to be the principal mediator of these effects.

Science and its application in assessing the welfare of laying hens in the egg industry

OBJECTIVE

To provide a rational framework for the scientific assessment of welfare and to use this framework to assess the welfare implications of issues relevant to the Australian egg industry.

PROCEDURE

A well-accepted approach to the assessment of animal welfare, based on assessing how well the animal is adapting, is described. This approach is used to consider the welfare implications of issues such as space, perches, nest boxes, dust baths, abrasive strips and non-cage housing systems.

CONCLUSIONS

The role of science in the welfare debate is to provide biological facts and thus it is important to separate welfare and ethics. The welfare of an animal in response to a housing system or husbandry procedure can be assessed by evaluating how much has to be done by the animal in order to cope and the extent to which the coping attempts are succeeding. Using this approach there is evidence for improved welfare from increasing space in cages, based on reduced aggression, corticosterone concentrations and mortalities and increased production, and for incorporating perches, based on the reduction in injuries at depopulation. Similar evidence for the inclusion of dust baths and nest boxes is lacking. The data on abrasive strips are equivocal with recommendations from overseas for their inclusion, whereas some local data have shown an increase in mortality can occur. Similarly, the data on non-cage systems are equivocal. The data on bone strength suggest improved fitness in non-cage systems, the data on stress suggest fitness may be better, similar or worse in non-cage systems, and the limited data on immunology suggest fitness may be worse in non-cage systems than in conventional cages.

Sexual behavior of male pigs

Two major characteristics of males that affect the likelihood of achieving copulation are the sexual motivation and mating competency of the male. The behavior of domestic animals, including their sexual behavior, is dependent upon a complex interaction between the organism's internal and external environment. In male pigs, as in other mammalian species, it is clear that testicular steroids are required to maintain sexual behavior and testosterone plays a critical role. Consistent with studies in other species, it is apparent in male pigs that there is a threshold circulating concentration of androgens and/or estrogens required to maintain sexual behavior and that the level of sexual motivation is unrelated to levels of sex steroids providing these are adequate for normal sexual behavior. Key aspects of the external environment that affect the sexual behavior of the male pig include genetic, seasonal, social, sexual and psychological factors.

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.

Susceptibility of reproduction in female pigs to impairment by stress or elevation of cortisol

It is generally agreed that stress can impair reproduction. Furthermore, it is often thought that cortisol, which is secreted during stress as a result of activation of the hypothalamo-pituitary adrenal axis, is associated with this stress-induced impairment of reproduction. It has been hypothesized that reproduction in females is particularly susceptible to disruption by acute stress during the series of endocrine events that induce estrus and ovulation. Nevertheless, we found no support for this conjecture when we subjected female pigs to repeated acute stress or repeated acute elevation of cortisol during the period leading up to estrus and ovulation. Conversely, studies have demonstrated that prolonged stress and sustained elevation of cortisol can disrupt reproductive processes in female pigs. Nevertheless, in each study that demonstrated this effect, there were some animals subjected to the prolonged stressor or the sustained elevation of cortisol in which the reproductive parameters that were measured were not affected by the treatment. We propose that reproduction in female pigs is resistant to the effects of acute or repeated acute stress or acute or repeated acute elevation of cortisol even if these occur during the series of endocrine events that induce estrus and ovulation. Furthermore, while reproductive processes in some individuals are compromised, reproduction in a proportion of female pigs appears to be resistant to the effects of prolonged stress or sustained elevation of cortisol.

Gender-specific effects of prenatal stress on emotional reactivity and stress physiology of goat kids

The aims of this study were to investigate the effects of maternal stress during pregnancy on the emotional reactivity, the hypothalamo-pituitary-adrenocortical (HPA) axis, and the sympatho-adrenomedullary (SAM) system of goat offspring according to their gender, and to investigate the role of maternal cortisol in prenatal stress effects. Goats were exposed to ten transports in isolation or ten ACTH injections (0.125 IU/kg body weight) during the last third of pregnancy. Control goats remained undisturbed. No effect of repeated transport during the last third of pregnancy was found on basal cortisol concentrations of the offspring. However, an increase in phenylethanolamine N-methyl transferase activity in the adrenals was observed in prenatally stressed kids compared to control kids (P = 0.031). In the presence of novelty, prenatally stressed female kids were more active (P = 0.049) than control females; they also showed more signs of arousal (P = 0.039) and tended to explore more of their environment (P = 0.053) in reaction to a startling stimulus. On the contrary, prenatally stressed male kids tended to be less active (P = 0.051) than control male kids but showed more signs of distress (P = 0.047) in the presence of novelty. Intermediate effects were found on the emotional reactivity to novelty of kids born from dams given injections of ACTH. In conclusion, transport stress in pregnant goats affects the sympatho-adrenomedullary system and the emotional reactivity of their offspring in a gender-specific manner. Moreover, the effects of prenatal transport and ACTH injections showed some similarities but differed in some critical details.

The relationships between characteristics of milking sheds and the attitudes to dairy cows, working conditions, and quality of life of dairy farmers

This study consisted of a survey of dairy farmers and their milking sheds at 198 Victorian dairy farms to examine the relationships between physical features in the milking shed and a number of job-related characteristics of the farmer, such as attitudes to handling cows and job satisfaction. Furthermore, farmers’ opinions of the effects of specific design features of the milking shed on cow behaviour were sought. A further objective of this survey was to use the relationships between shed characteristics and job-related characteristics of the farmer to identify, for future research, possible features of the milking shed that may affect cow behaviour. There was substantial variation in both the behavioural beliefs of farmers about cow behaviour in the milking shed and reports by farmers on comfort and working conditions in the dairy, indicating that considerable opportunities exist to improve these key job-related characteristics. A principal component analysis (PCA) of the responses to the questions on job-related characteristics of the farmer identified 6 factors: 2 of the factors identified were related to behavioural beliefs by farmers about cow behaviour (labelled ‘Cow Movement’ and ‘Cow Behaviour’); one of the factors related to comfort of the farmer in the shed (labelled ‘Operator Comfort’); and 3 of the factors related to aspects of the quality of life of the farmer (labelled ‘Workload’, ‘Farmer Mood’, and ‘Job Characteristics’). Positive beliefs about both cow movement (factor called Cow Movement) and cow behaviour (factor called Cow Behaviour) were correlated with farmers being more positive about working in the dairy (factor called Operator Comfort; P < 0.05 and P < 0.01, respectively) and the characteristics of the job (factor called Job Characteristics; P < 0.01). These relationships suggest that improvements in cow behaviour may lead to improvements in both job satisfaction and the quality of life of the farmer. Furthermore, regression analysis revealed that a number of the shed features, such as height of the breast rail, presence of stall gates, length and width of the platform and solid side on first milking bail, were significant predictors of one or more of these 6 PCA factors. Although these results may not reflect causal relationships, these relationships between shed characteristics and a number of job-related characteristics of the farmer highlight the potential importance of shed design to both the cow and the farmer and provide a valuable guide in identifying features of milking sheds that require future examination as to their effects on cow behaviour.

Sources of sampling variation in saliva cortisol in dogs

The main advantage of collecting saliva cortisol as opposed to plasma cortisol is that it is non-invasive and therefore it is now widely used in stress measurement studies on farm animals and dogs. Although a plasma cortisol response to handling associated with blood collection generally occurs at 3 min from the commencement of handling, there is no information in the literature on the time course of the response of salivary cortisol concentration to handling. The aims of these experiments were to (1). determine if there is a response to up to 4 min handling that affects cortisol concentration in saliva and (2). determine the main causes of variation in saliva cortisol in dogs over time. In experiment 1, saliva was collected from six Kelpies at 0 min then 2, 3 or 4 min after the commencement of restraint. There was no handling effect found in up to 4 min sampling time. In experiment 2, saliva was collected from six Labrador Retrievers five times in 2 h (14:00-16:00), three days a week for four weeks. Some of the sources of variation in saliva cortisol over time included between dog variation that varied over a period of days and variation between occasions that affected the group of dogs as a whole.

Susceptibility of reproduction in female pigs to impairment by stress and the role of the hypothalamo-pituitary-adrenal axis

Although it is generally considered that stress can impair reproduction, we suggest that the impact of acute or repeated acute stress or acute or repeated acute elevations of cortisol are of little consequence in female pigs, even if these occur during the series of endocrine events that induce oestrus and ovulation. It is important to understand the impact of acute stress on reproduction because, in the intensive production of livestock, animals are often subjected to short-term challenges. There seems little doubt that reproduction in a proportion of female pigs is susceptible to impairment by severe and prolonged stress or the sustained elevation of cortisol but only when this continues for a substantial period. In female pigs, where reproduction is susceptible to impairment by severe prolonged stress, it is possible that the mediators of this suppression are cortisol, corticotrophin-releasing factor and vasopressin but, in pigs, there is evidence to suggest that adrenocorticotrophic hormone is not involved. Other substances secreted during stress may be involved but these are not considered in this review. It is possible that the mediators of stress act at any level of the hypothalamo-pituitary-ovarian axis. Although a variety of experimental manipulations have provided potential mediators and mechanisms for the stress-induced suppression of reproduction, these experimental manipulations rarely represented physiological circumstances so it is not clear if such mechanisms would be important in a physiological context. The precise mediators and mechanisms by which hormones released during stress may inhibit reproductive processes during severe prolonged stress are yet to be determined.

The effects of fear of humans and pre-slaughter handling on the meat quality of pigs

This study using 90 commercial pigs examined the relationships between the handling that pigs received immediately prior to slaughter and some measures of their meat quality. A number of significant correlations were found between the number of negative interactions that pigs received from the stockperson and subsequent meat quality of the pigs. For example, the number of highly negative interactions received by the pigs was negatively (P < 0.01) correlated with plasma glucose concentrations post-slaughter and positively correlated (P < 0.05) with both post-slaughter plasma lactate concentrations and the light reflectance of the ham. Most of these highly negative interactions were prods with an electric goad. Both the number of interactions by the pig with the experimenter in a standard test used to assess fear of humans and the time taken by the pig to move along the final route to the stunning area were positively correlated (P < 0.05) with the number of highly negative interactions received by the pig prior to slaughter. Regression analysis revealed that the number of highly negative interactions received by the pig, plasma lactate concentration, and the time to physically interact by the pig with the experimenter in the standard test were significant (P < 0.001) predictors of ham lightness. These variables accounted for 18% of the variance in ham lightness. It is concluded that there are some important associations between the behaviour of the stockperson and the muscle physiology of pigs. Although no significant associations were found between stockperson behaviour and ham pH, the correlations between stockperson behaviour, plasma lactate and glucose, and muscle lightness reflect increased muscle glycogenolysis, presumably associated with increased handling stress prior to slaughter. Such results indicate the opportunity to manipulate the behaviour of stockpeople prior to slaughter to improve meat quality.

The effects of cognitive behavioral intervention on the attitude and behavior of stockpersons and the behavior and productivity of commercial dairy cows

Two experiments, one involving 29 commercial farms and the other involving 94 commercial farms, were conducted to examine the effects of a training program targeting a number of attitudinal and behavioral variables in stockpeople. These stockperson variables had been previously shown to be related to fear of humans and productivity of commercial cows. In both experiments, two treatments were imposed: an Intervention treatment, consisting of a cognitive-behavioral intervention procedure designed to improve the attitude and behavior of stockpeople toward cows, and a Control treatment, in which no intervention was attempted. In Exp. 1, an analysis of covariance, using previous lactation variables as the covariate, revealed effects of the Intervention treatment on the attitude and behavior of the stockpeople and the behavior of cows. Stockpeople at Intervention farms showed more (P < 0.01) positive beliefs about handling cows and used a lower (P < 0.05) number and percentage of negative tactile interactions in handling cows than stockpeople at the Control farms. Cows at the Intervention farms showed a shorter (P < 0.05) flight distance to humans, indicating a lower level of fear of humans by these cows. However, 36% of the Intervention farms failed to show a reduction in average flight distance over the two lactations. Although there was no significant treatment effect on milk yield, the Intervention farms in which fear levels declined following the intervention had a higher (P < 0.05) milk yield than the other farms. In Exp. 2, a significant (P < 0.05) increase was found in the milk yield of cows following the Intervention treatment. Similar treatment effects were observed on both milk protein and milk fat. These results indicate that cognitive-behavioral interventions that successfully target the key attitudes and behavior of stockpeople that regulate the cow's fear of humans offer the industry good opportunities to improve the productivity of cows.

A review of the welfare issues for sows and piglets in relation to housing

This review of sow welfare addresses all aspects of housing for adult female pigs, including the issue of piglet welfare during lactation. It puts the issue of sow welfare in perspective by briefly outlining different approaches to the scientific assessment of welfare, the ‘feelings, preference, nature, and the functional or homeostasis’ approaches. We believe the last approach currently offers science the best assessment of welfare and is the approach that is utilised in this review. It involves comparing housing or husbandry systems and risks to welfare on the basis of relative changes in biological (behavioural and physiological) responses and corresponding decreases in fitness (growth rate, reproductive performance, or health/injury/immunology). The review discusses the following areas: (i) housing of individually housed pregnant pigs, with subsections on tethers, stalls, reproductive performance, exercise, and new stall designs; conventional, alternative, and outdoor group housing with subsections on aggression, electronic feeding stations, ecoshelters, and other alternative group housing designs; and other issues, such as lameness, culling, straw and other substrates, diet and hunger, quality of stockpeople, and housing around mating including oestrus detection and mating; and (ii) farrowing and lactating pigs with subsections on farrowing crates and alternative farrowing systems, stress around farrowing and during lactation, maternal behaviour and piglet survival, and sow and piglet injury and lameness. Conclusions and recommendations arising from the review include the need for public education to provide an informed consumer base that will result in some consensus on welfare issues among diverse interest groups and the need for industry education that results in better animal welfare and a sustainable industry. Some specific research recommendations include space allowance and the duration of housing for individually housed pigs, welfare issues of breeding sows in ecoshelters, piglet mortality in alternative systems, aggression in conventional and large groups, bedding, and hunger.