Effects of repeated changes in group composition on immune response, behaviour, adrenal activity and liveweight gain in farmed red deer yearlings

The good, the bad, the comfortable: a review of welfare practices and indicators based on the five domains model in farmed deer

Increasing consumer interest in game meat has globally expanded wild animal farming, with deer being a prominent non-traditional species farmed in numerous countries. Consequently, methods for assessing the welfare of captive animals have been developed over the last few decades, and despite its limitations, the Five Domains Model has become one of the most popular practical tools for welfare assessment. Our review focuses on welfare indicators in farmed red and fallow deer, the primary deer species in European farms. Among 57 studies, the majority emphasized deer health and nutrition, neglecting aspects like behavior and mental state. Notably, a significant portion explored human-animal interactions, especially in deer transportation. Summarizing literature for each domain, we propose reliable physical, behavioral, and physiological welfare indicators for farmed red and fallow deer. This comprehensive approach addresses current research gaps and contributes to enhancing the overall well-being of farmed deer.

Start early! Does social instability during the pre- and early postnatal development prepare male wild cavies for social challenge later in life?

BACKGROUND

The social environment the mother experiences during pregnancy and lactation can powerfully influence the offspring's behavioural profile. Our previous studies in wild cavies show that two different social environments during pregnancy and lactation bring about different behavioural strategies of male offspring later in life: An unstable social environment leads to a behavioural camouflage strategy, hypothesised to be beneficial at times of socially challenging situations. A stable social environment during early phases of life, however, leads to an early reproduction strategy, expected to be more successful at times of social stability. In the present study, we observed the behavioural strategies of the two types of males in direct comparison in a socially challenging situation: Two adolescent males were placed simultaneously in an unknown social group consisting of one adult male and two females in a semi-naturalistic environment. Cortisol as well as testosterone concentrations and activity levels were compared. Furthermore, paternities were analysed after the males reached sexual maturity. We hypothesised that sons showing a behavioural camouflage strategy are better adapted to cope with this socially challenging situation compared to those displaying an early reproduction strategy.

RESULTS

At the beginning of the experiment, no differences in plasma cortisol concentrations between the males were found, both showed a highly significant increase due to the challenging situation. From day 5 until the end of the experiment (duration = 40 days) sons showing an early reproduction strategy had significantly higher plasma cortisol concentrations compared with those showing a behavioural camouflage strategy. Plasma testosterone concentrations did not differ significantly. Activity levels decreased significantly over time independently of the male's behavioural strategy. Both types of males did not sire offspring during the observation period.

CONCLUSION

Higher cortisol values from day 5 until the end of the experiment in sons showing an early reproduction strategy indicate higher levels of stress in these males compared to those displaying a camouflage strategy. We conclude that the modulation of the males behavioural strategy due to an unstable social environment during early development facilitates the endocrine adaptation to a comparable social situation later in life.

Anthropogenic pollutants – an insidious threat to animal health and productivity?

Summary

Welfare of farmed deer in New Zealand. 1. Management practices

This review summarises research of management practices that potentially impact on the welfare of farmed deer. The processes of capture and initial domestication of feral deer caused many welfare problems but are now essentially complete in New Zealand. The health and production status of farmed deer, and readily visible indicators of their welfare are generally good, although preventive medicines and optimum management practices have not been universally adopted. Research into social behaviour, effects of yarding, weaning, mating, calving, shelter, shade and nutrition has identified ways of improving the welfare of farmed deer and has provided recommendations for deer industry quality assurance programmes. Research has identified transport design and practices that minimise the impact of transport on deer welfare and reduce carcass wastage caused by bruising during transport. Time in lairage prior to slaughter should be minimised and electrical stunning is a humane method of slaughter. Ongoing research is needed on management practices and farm environments to further improve the welfare of farmed deer, consistent with the goals of the New Zealand deer industry and its proactive approach to date.

Effects of isolation on the behaviour, live-weight gain, adrenal capacity and immune responses of weaned red deer hind calves

At weaning at 3 months of age (week 1), 30 red deer hind calves were housed in six groups of five animals at a stocking density of 1·5 m2 per head and maintained in these groups for 4 weeks. At the start of week 5, all calves were immunized with ovalbumin (OVA). Fifteen calves, from three groups, selected at random, were transferred to individual pens which restricted visual and tactile contact with others (ISO) while the remaining animals were kept in their groups (GP). The behaviour, food intake, live-weight gain, antibody and lymphocyte responses in vitro to OVA and lymphocyte responses in vitro to the non-specific mitogen, concanavalin A (ConA), of all calves were assessed in each of weeks 5 to 9. Isolated calves had a lower mean live-weight gain than GP calves (P < 0·001), although there were no differences in food intake. Significantly more time was spent lying (P < 0·001) but less time feeding (P < 0·05) and self-grooming (P < 0·001) by ISO than by GP calves. There was no significant difference between ISO and GP calves in the cortisol response to an ACTH challenge test (10 i.u.) at week 11. Lymphocyte responses and antibody titres to OVA were lower in GP than in ISO calves at weeks 7 (P < 0·05) and 8 (P < 0·05), respectively. In contrast, GP calves had greater lymphocyte responses to the non-specific mitogen, ConA, in weeks 7 (P < 0·05) and 10 (P < 0·001) but not in week 9 compared with ISO calves. Differences in lymphocyte stimulation were attributed to the non-specific mitogenic nature of ConA. Factors such as agonistic interactions evident in group housing may have compromised the antibody and lymphocyte responses to OVA by GP calves but conversely the lack of social contact may have also suppressed behavioural activity in ISO calves.

The effect of post-capture management strategy on the welfare and productivity of wild red deer (Cervus elaphus) hinds introduced to farming systems

Wild red deer (Cervus elaphus) hinds were subjected to one of five post-capture management strategies during the period from capture in late pregnancy in March, until weaning in September. The treatments were: remained enclosed at the capture site; relocated to a remote site; relocated to a conventional deer farm on improved pasture; relocated to a conventional deer farm and grazed with farmed hinds; housed prior to calving on a conventional deer farm site. For a further year, all hinds were managed under conventional deer farm conditions. There was considerable evidence, based on mortality and behaviour, to suggest that initial housing of the hinds following capture compromised their welfare. Deaths of hinds (seven out of 20) occurred in this group, associated with bullying during the housed period. Hinds on this treatment also showed a higher frequency of aggressive interactions compared with the groups directly moved to the deer farm (11% v. 2% respectively of scans conducted at 10-min intervals over 6h; P < 0·001) and a reduced level of lying behaviour (15% v. 34 to 47% of scans; P < 0·001) during the gestation period. Similarly, during the calving period, this group lay the least (27% v. 43 to 72% of scans; P < 0·001) and the mean number of interactions between hinds reached 11·7 compared with 1·5 to 4·9 (F < 0·001) in the other groups over a continuous 6-h recording period. The two groups of hinds relocated directly onto sown swards were generally similar to one another in terms of behaviour and performance. However, the group mixed with farmed hinds suffered from considerable calf losses in year 1 due to disease (four out of 12). Losses of hinds over winter in year 1 (nine out of 90) occurred principally amongst those animals which had not become habituated to human presence or supplementary feeding in the summer, i.e. groups remaining enclosed at the capture site or relocated to a remote site. When all hinds were treated similarly in year 2 the hinds from these same two groups, together with those initially housed indoors, showed more hind-hind interactions overall than the two groups located directly onto the deer farm (7·2 v. 3·1 interactions per hind over a 4-h period; P < 0·02) and it is suggested that these hinds had not yet adapted to their new environment. An ACTH stimulation test conducted during year 2 supported the view that the two groups of hinds most recently introduced into the managed system were subject to a chronic stressor at the time of testing, since administration of ACTH did not elicit a significant increase in plasma cortisol concentrations (mean values pre- and post-ACTH 188 and 217 nmol/l respectively). In contrast, the mean plasma cortisol concentrations of the two groups managed under extensive farm conditions from the outset, showed a significant rise (pre- and post-ACTH, 261 and 376 nmol/l respectively; P < 0·01). From this it is concluded that their adaptation to the farm environment had already occurred. The live-weight gains of the wild hinds calves (229 g/day) on the improved pastures in the 1st year of the study were below that for farmed hinds calves (282 g/day; P < 0·05), suggesting that they were not habituated to the management system. However, by the end of year 2 animal performance was comparable with that of farmed hinds and calf growth rates reached 276 g/day. Thus while housing wild red deer immediately after capture is associated with poor welfare, analysis of behaviour, adrenal response and animal production over a longer period suggests that by the end of the study few important differences remained between the groups.

Behavioural and physiological responses of sheep of different breeds to supplementary feeding, social mixing and taming, in the context of transport

Three experiments investigated differences between sheep breeds in response to supplementary feeding and very close confinement with familiar and unfamiliar sheep; and differences between individuals in response to a taming procedure prior to transport in a trailer. The first two experiments were with a mixed flock of Clun Forest lambs and crossbred lambs from Orkney. An initial tendency to feed with others of the same breed diminished over 3 weeks. Responses of heart rate and salivary cortisol concentration when one sheep (the visitor) was penned in an enclosure of 1 m2 with three other sheep of the same or the other breed (the trio group), did not depend on whether the visitor and the trio group were of the same or different breed. Clun Forest sheep showed little response while Orkney sheep showed increased heart rate and some elevation of salivary cortisol concentration. In the third experiment, 34 Beulah Speckled Face ewes were divided into two groups one of which was subjected to a taming procedure over a period of 3 weeks. Response of salivary cortisol concentration to subsequent journeys of 2h in a livestock trailer did not differ between tamed and untamed sheep. There were individual differences in the response to taming and this was correlated with the cortisol response during transport, in that those sheep which responded most to taming showed the least elevation during transport.

Removing individual rats affects indicators of welfare in the remaining group members

The removal of individuals from social groups, e.g. in order to maintain appropriate stocking densities in groups of rapidly growing young laboratory rats, is often necessary. However, such removals may be stressful and few studies have investigated their effects on the behaviour, physiology and welfare of the remaining group members. In this study we investigated this issue for rats housed at different stocking densities by observing behaviour and recording faecal corticosterone metabolite levels both before and after removal. We found that, irrespective of stocking density, the rats remaining in the home cage significantly increased agonistic behaviour, audible vocalization, aggressive grooming, bar-chewing and climbing behaviour following removal of their cage-mates, and that these behavioural changes were associated with a highly significant post-removal increase in their faecal corticosterone metabolite levels. Taking the behavioural and physiological results together, it appears that the removal of individuals from groups of young laboratory rats resulted in social stress, and thus an apparent impairment of welfare.

Survey on 'lumpy jaw' on deer farms in western Canada: prevalence and distribution, and identification of associated factors

AIM

To investigate the prevalence and geographical distribution of 'lumpy jaw' (LJ) in a population of white-tailed deer (WTD; Odocoileus virginianus) and mule deer (MD; Odocoileus hemionus) farms from the western Canadian provinces of Saskatchewan and Alberta, and to identify factors associated with its occurrence.

METHODS

A cross-sectional study, in which the target population was all farmers of WTD and MD registered in Saskatchewan and Alberta, was conducted between July 2004 and January 2005. A questionnaire was mailed to all farmers requesting information about the presence of LJ and other necrobacillosis- related syndromes (footrot and fawn death syndrome), and various farm characteristics, during 2002, 2003 and 2004. Herd and within-herd incidences of disease were estimated. Global and local spatial analyses were performed to identify possible clusters of occurrence of LJ in the region. Logistic regression analysis was used to identify factors associated with the occurrence of LJ.

RESULTS

A total of 139/268 (52%) deer farmers responded to the survey. Over the entire study period, 108/139 (78%) of farmers reported having cases of LJ in their herds, and in any given year the incidence amongst herds was about 40%. The presence of footrot was not associated with the presence of LJ. The proportion of fawns dying suddenly in 2004 was higher on farms affected by LJ than in those considered LJ-free (median of 11.1% and 0%, respectively; p<0.001). Two areas in Saskatchewan were identified as having a higher herd prevalence of LJ (clusters) than all other areas. Density of animals, moving and handling animals, lack of basic hygiene measures, and bottle- feeding of fawns increased the odds of a herd being affected by LJ.

CONCLUSIONS AND CLINICAL RELEVANCE

LJ should be considered a common disease in farmed deer in western Canada. The observed relationship between the occurrence of LJ and acute mortality of fawns emphasises the potential of this infection to result in significant economic loss. Intensive management of deer, characterised by high densities and frequent moving and handling of animals, may contribute significantly to the occurrence of LJ. Observed geographical clusters may reflect areas where management of deer was more intensive or the trading of deer more common.

The welfare of low-volume farm animals during transport and at slaughter: a review of current knowledge and recommendations for future research

Meat from low-volume farm animals such as farmed deer and wild boar is currently widely available to the consumer within the UK. Despite a rapid growth in production of these species there is a paucity of research that focuses on their welfare. This paper reviews the current literature and legislation relating to the transport and slaughter of farmed deer, wild boar, ostriches, buffalo and bison in order to identify priorities for future research. Research on low-volume farm animals has focused on red deer and their welfare is safeguarded with comprehensive legislation and guidelines. Studies have indicated the importance of appropriately designed facilities and sympathetic handling of red deer to ensure humane slaughter with minimal stress. However, the impact of transport and slaughter on the welfare of other deer species has not been recorded and this should be recognised. Much research has been conducted on the welfare of ostriches during transport and at slaughter. However, many of the results are discordant and research is required to clarify, in particular, posture during transport and stunning methods. Research on the welfare of wild boar, buffalo and bison is scarce. Best practice for both transport and slaughter of these species needs further research and clarification within legislation. For the low-volume species discussed in this review, priorities for further research include (1) appropriate methods of handling to minimise stress during transport and slaughter; (2) identification/clarification of appropriate slaughter methods and (3) training of transport and abattoir personnel in handling and slaughter methods.

Effect of repeated regrouping and relocation on the physiological, immunological, and hematological variables and performance of steers

To investigate the effect of repeated regrouping and repenning (R&R) on the hypothalamic-pituitary-adrenal axis, immune function, blood biochemical and hematological variables, and ADG, 72 Holstein-Friesian (14-mo-old; 441 +/- 3.2 kg) steers were assigned to either the control (C; n = 30) or regrouped (R; n = 42) treatments and housed six per pen in 12 pens. The R steers were exposed to six R&R over 84 d. New pen cohorts were allowed to stabilize for 14 d, and none of the R steers was allowed to share the same pen or penmates where or with whom they were previously housed. Control steers were housed in the same pen with the same penmates. Steers were blood sampled 2 h before and 2 h after the first, third, and sixth R&R. Steers were weighed the day before each R&R. Median area under the plasma cortisol curve (AUC) was greater (P < 0.05) in R than C steers after the first R&R. Following the first, third, and sixth R&R, the median ACTH AUC did not differ between the treatments. Cortisol AUC in R steers decreased (P < 0.001) following the third and sixth compared with the first R&R, however, cortisol AUC in response to exogenous ACTH (following administration of dexamethasone at -12 h) after the third R&R was greater in C than R steers (P < 0.05). Corticotropin-releasing hormone-induced cortisol and ACTH AUC were not different in C vs. R after the sixth R&R. There were no differences among treatments in haptoglobin, fibrinogen, and concanavalin A-induced interferon-gamma after the first, third, and sixth R&R. Albumin, urea, and NEFA were greater (P < 0.05) in R than C steers after the first R&R. beta-Hydroxy-butyrate and glucose concentrations were greater (P < 0.05) in R than C, whereas no changes in the protein and globulin concentrations were found in C vs. R after the sixth R& R. White blood cell, differential and total count, red blood cell, and platelet numbers did not differ in C vs. R after the first and third R&R. Lymphocyte numbers and mean corpuscular volume were greater (P < 0.05) in R than C steers after the sixth R&R. Monocyte numbers were greater (P < 0.05) in R than C steers following first R&R. There was no difference in the overall ADG in C vs. R; however, there was a tendency (P = 0.10) for lesser ADG by R than C steers following second R& R. In conclusion, steers exposed to R&R responded with increased plasma cortisol, albumin, urea, and NEFA. Repeated R&R did not have a sustained detrimental effect on immune and production measurements.

Effects of pulsed or continuous infusion of cortisol on immune function in sheep

It was postulated that frequent pulses of cortisol such as might be induced by a repeated or chronic stressor, could induce immune suppression and that the effect would be greater than in animals subjected to less frequent increases. Four groups of nine adult Scottish Blackface ewes were infused for 14 d with saline or hydrocortisone hemisuccinate (cortisol) delivered continuously or in pulses. Plasma concentrations of cortisol were significantly elevated (to between approximately 100 and 1000 nmol/liter; P < 0.001) for about 30 or 75 min after infusion of pulses of hydrocortisone hemisuccinate at intervals of 1 hr (P1) or 6 hr (P6), respectively. In animals continuously infused (CI), they were consistently elevated (P < 0.001), compared with concentrations in control animals infused with saline only (S), to approximately 1000 nmol/liter or more. Antibody production in response to ovalbumin injection was not affected by any of the infusion regimes. At Days 10, 24, and 31 after injection of ovalbumin and initiation of the infusion, rates of multiplication of unstimulated lymphocytes, in vitro, were greater (P < 0.05) in P6 animals than in saline-infused, control animals and this resulted in a reduction in the stimulated lymphocyte response. As a consequence of the increased basal lymphocyte activity, after Day 0, the corrected, stimulated lymphocyte response of P6 animals was consistently below that of controls (P < 0.05 at Day 24). Both mean basal and stimulated lymphocyte activities in CI and P1 animals were similar to those of controls. The gamma interferon (IFN-gamma) response was generally small and not affected by treatment. It is concluded that large, relatively infrequent increases in circulating cortisol concentrations can modify the cell mediated immune response such that the response to a specific antigen challenge is compromised but smaller, more frequent pulses had no effect. Elevated cortisol concentrations per se did not have a significant inhibitory effect on the immune system.

Farmed deer: a large animal model for stress

In the early classic period it was suggested by Heracleitus that a static unchanged state was not the natural condition, but rather that the capacity to undergo constant change was intrinsic to all living things. After that, Empedoeles, circa 500 BC, proposed that for living organisms to survive they require a harmonious mixture of elements. Hippocrates, around 400 BC, developed this concept further by suggesting that health is a state of harmonious balance of these elements, equating disease to a state of disharmony and introducing the concept that nature heals disease (Noysvn Fyseiw/atrui). Soon after, Epicurus extended these ideas to include among these healing forces, the mind, writing that imperturbability of mind is desirable. Claude Bernard introduced the concept of the milieu interieur or the internal physiologic environment, describing its constancy as essential in an external environment typified by its variability. Walter Cannon described Bernard's constancy as Homeostasis and identified the "fight or flight reflex," linking the adaptive response and catecholamine secretion, with extreme levels of activation-producing pathology. Selye outlined four stages of the stress response: 1) the "alarm reaction" characterized by an immediate activation of the sympathetic-adrenomedullary axis (SA); 2) a "resistance phase" characterized by hypothalamic pituitary-adrenal axis (HPA) activation; 3) a stage of adrenal hypertrophy, gastrointestinal ulceration, along with thymic and lymphoid atrophy; and 4) an exhaustion phase and finally death (1).

Relations between oral stereotypies, open-field behavior, and pituitary-adrenal system in growing dairy cattle

The aim of this study was to investigate possible differences between calves with or without stereotypies concerning their behavioural reaction to an acute stress situation such as an open field and their behavioural and pituitary-adrenal responses to long-term tethering. Behavioural observations, open field tests, sampling for baseline adrenocorticotropic hormone (ACTH), and adrenocortical response tests after synthetic ACTH administration were made on 48 4- to 7-months-old dairy calves housed in tether stalls. Behavioural observations and blood sampling for baseline ACTH and cortisol determination after synthetic ACTH were repeated a year later in the same animals. Individual stereotypy levels showed a high correlation between calf values and heifer values (p < 0.001). Baseline ACTH in the calves was related to individual stereotypy levels (p < 0.05) in that the calves with higher stereotypy levels had lower ACTH values. The release of cortisol after injection of synthetic ACTH was considerably higher in the animals as heifers than when they were calves (p < 0.001). There was a relation between adrenocortical response to ACTH and stereotypy level in the heifers, showing that the higher the stereotypy level, the lower the cortisol response (p < 0.05). In the open field tests, the calves with the highest stereotypy levels moved around least but explored most. In conclusion, this study shows that growing dairy cattle with relatively high levels of oral stereotypies differ from individuals devoid of, or with low stereotypy levels, in behavioural response patterns to a short-term stressor such as an open field in adreno-cortical responses to exogenous ACTH and in baseline ACTH after 2 weeks of tethering.

Physiological responses of red deer (Cervus elaphus) to conditions experienced during road transport

Remote heart rate and blood sampling devices were attached to transported red deer stags to assess the effects of several road transport parameters on physiological responses associated with welfare. Stocking density had a significant influence on heart rates and plasma lactate concentrations. Heart rates of deer transported at a high density (0.38 m2 per 84 kg animal) were 10-13% higher than those of deer transported at medium (0.62 m2) or low densities (0.85 m2). Lactate concentrations of animals transported at a high or medium density were 30-40% higher than those of deer transported at a low density. Heart rates of deer transported in the back or middle pens were 7-8% higher than those of deer transported at the front, and lactate concentrations were 30-40% higher. Because elevated heart rates and lactate concentrations are indicative of physiological or psychological challenges, it may be best to transport deer at densities below the currently recommended limit (0.40 m2/100 kg animal) and to keep deer nearer the front of the crate. Although hematocrit, sodium, and cortisol concentrations were not sensitive to variation in stocking density or the animal's position within the crate, cortisol and sodium concentrations increased significantly with time in transit; heart rates and lactate concentrations decreased significantly during the journey. A 2-fold increase in cortisol during the 2-h trip suggests that the length of journeys should be minimized to avoid welfare problems.