The influence of early contact with humans on subsequent behavioural response of pigs to humans

This study examined the influence of three handling treatments, imposed from birth to 8 weeks, on the approach behaviour of 24 pigs to humans at 10–24 weeks of age. Piglets in two treatments, weaning/handling and handling, regularly received human contact, while piglets in the third treatment, no handling, only received human contact during routine husbandry. Piglets in the weaning/handling treatment were artificially reared, while those in the other two treatments remained on the sow until weaning at 4 weeks of age. Pigs in the weaning/handling and handling treatments showed increased approach to a stationary human in six tests from 10 to 24 weeks of age. For example, piglets in the weaning/handling and handling treatments spent more (P<0.01) time within 0.5 m of the human and were quicker (P<0.05) to physically interact with the human than pigs in the no handling treatment. Observations on the sexual behaviour of the boars from 25 to 35 weeks of age indicated that handling had no adverse effects on sexual behaviour.It is concluded that early handling of pigs will influence their behavioural response to humans later in life. Therefore, early handling may be a practical method for man to manipulate the pig's subsequent relationship with humans. The possibility of the existence of a “sensitive period” for “socialization” in pigs is discussed in the light of the present results.     

Comparison of the effects of two different handling methods on the subsequent behaviour of Anglo-Arabian foals toward humans and handling

Tactile contact is often used to improve the human–foal relationship, in particular during sensitive periods such as weaning. However, the method used to provide the contact (forced or unforced) may affect subsequent reactions to humans. The aim of our study was to compare the effect of forced and unforced handling at weaning on horses’ behaviour towards humans and handling.A total of 23 Anglo-Arabian foals received individual human contact at weaning. Constrained-handled foals (forced human contact; FC, n = 8) were stroked while being restrained (i.e., held by the halter without being led) so that human contact was forced. Unconstrained-handled foals (unforced human contact; UC, n = 7) were stroked without any restraint and could thus avoid contact if they so wanted. Each individual was handled 5 min twice a day for 14 consecutive days. Control foals were not handled (no contact; NC, n = 8). Foals’ reactions towards a human (e.g. proximity and contact seeking), and their manageability (fitting of a halter) were then assessed. The animals from the different treatments were then mixed and tested again 4 months later. Non-parametric Mann–Whitney U-tests were used to compare experimental groups.Only forced human contact reduced fear reactions toward humans (e.g. shorter latency to approach a passive human, P < 0.01; shorter latency to touch the foal, P < 0.05) in the short-term (immediately after the handling sessions) and increased foals’ manageability in a familiar environment (shorter latency to be placed a halter on and less defences displayed, P < 0.05). It had no effect in an unfamiliar environment. These effects did not last longer than 4 months.Forced human contact thus appears to be more efficient in improving human–horse relationships and subsequent handling than unforced human contact. However, the lack of effect on reactivity towards humans in an unfamiliar environment, and the lack of long-term effects suggest that this method needs to be improved to be more effective. Some of our results suggest that horses could perceive human contact (i.e., stroking) as positive, however further studies are needed to confirm this hypothesis.     

Effects of bleeding nonanesthetized wild rodents on handling mortality and subsequent recapture

Handling mortality and recapture rates of wild rodents that were bled from the retroorbital capillary plexus without anesthesia were assessed. In 9,670 captures of seven species of rodents from 1994 through 1998, we found no difference in handling mortality in bled mice compared to those from trapping grids where mice were not bled. Recapture rates of rodents on control (non-bleeding grids) and rodents on bleeding grids was not significantly different for any species. We conclude that bleeding in the absence of anesthesia does not affect immediate mortality or subsequent recapture.     

Evaluation of on-farm veal calves’ responses to unfamiliar humans and potential influencing factors

The human–animal relationship is an important component of the welfare of farm animals and for this reason animal responsiveness tests to humans are included in on-farm welfare assessment schemes that provide indicators for this. However, apart from the behaviour of stockpersons towards their animals, other factors may also influence animals’ reactivity to humans as observed through behavioural tests, which can add a further layer of complexity to the interpretation of test results. Knowledge of these factors may help a better interpretation of differences from one farm to another in the outcome of human–animal relationship tests, and may provide clues for improving the relationship between animals and humans. The main objective of this study was to identify whether management or environmental factors could influence the outcome of human–animal relationship tests in veal calves. Two tests were performed when calves were aged 14.9 ± 1.6 (SD) weeks in 148 veal farms: the voluntary approach of an unfamiliar human standing at the feeding fence and the reaction towards an unfamiliar human who entered the home pen and tried to touch each calf in a standardised way (Calf Escape Test (CET) – score 0 to 4). Questionnaires were filled in and interviews with the stockpersons were performed in order to obtain information on stockpersons, management, animal and building characteristics. The latency to touch an unfamiliar human at the feeding fence was significantly correlated with the CET scores. Total number of calves on the farm, space allowance, breed, environmental enrichment, stockperson's experience and season of observation influenced the percentage of calves that scored 0 in CET (i.e. calves that could not be approached). Type of milk distribution, type of breed and number of calves per stockperson influenced the percentage of calves that scored 4 in CET (i.e. calves could be touched). For both CET0 and CET4, the level of self-reported contacts by the stockperson (analysed only on the French subset of 36 farms) did not influence the results. This paper concludes that according to the tests conducted on veal calves on commercial farms, factors such as milk distribution method, breed of the calves or the level of experience of stockpersons with veal farming can have an impact on the results of tests focusing on human–animal relationships.     

Effects of early undernutrition and handling on the adrenocortical activity of neonatal rats

Early neonatal experiences such as handling or undernutrition may alter developmental patterns associated with brain maturation and neuroendocrine regulation. Therefore, we tested neonatal ACTH and corticosterone responses to ether stress in pups submitted to chronic underfeeding which involves daily handling (U), daily handling only (H), or no handling (I). Pituitary ACTH content and brain myelin basic protein (MBP) content were measured in all rat groups. We found that the order of magnitude in stress-induced ACTH secretion was: I greater than H greater than U on day 14 and 18 of age while on day 10, only a small significant response in the H group was observed. Corticosterone secretion after stress was increased on day 14 in both H and I rats while no response was observed in the U group at all ages. Pituitary ACTH content of U pups was significantly (p less than 0.01) reduced compared to H rats on day 10 of age but not later. Underfeeding had profound effects on MBP synthesis of U rats since brain MBP content on day 14 was 5-fold lower in U versus H pups. In addition, handling enhanced MBP production since H rats exhibited higher (p less than 0.05) MBP content as compared to I rats. Thus, both handling and undernutrition experienced early in life are able to affect central brain maturation as well as neonatal adrenocortical responses to stress.     

Avoidance reactions of domestic dogs to unfamiliar male and female humans in a kennel setting

Most kennel owners and veterinarians prefer women assistants because these animalcare professionals assume that women elicit less avoidance from domestic animals than men. To evaluate this assumption, 10 male and 10 female dogs were given two human-reaction tests to assess their behavior in the presence of an unfamiliar man or woman in a commercial kennel setting. Female dogs showed little reluctance to approach and make contact with the unfamiliar human, regardless of the person's gender. In contrast, male dogs were much less likely to approach and make body contact with the unfamiliar man.     

Reactions of calves to handling depend on housing condition and previous experience with humans

This study investigated the influence of stockperson's behaviour and housing conditions on calves' behavioural reactions to people, and behavioural and physiological reactions to handling and short transport. Sixty-four Finnish Ayrshire male calves were used; half of them were housed in individual pens, the other half were housed in group pens of two calves. In both housing conditions half of the calves received minimal contact from the stockperson, while the other half were stroked on their necks and shoulders for 90s a day, after milk meals. The effects of housing and contact with the stockperson on the responses of calves to people, either entering or approaching the pen, were studied. Furthermore, calves' behavioural and physiological (cortisol, heart rate) reactions to being loaded onto a truck, transported for 30min and unloaded were observed. When a person entered the home pen, calves housed by pairs took significantly more time to interact and interacted less frequently with the person than individually housed calves did (p<0.01). Calves that received additional contact interacted for longer time with the unfamiliar person than calves with minimal contact (p=0.02). When a person approached the front of the calves' pens, less withdrawal responses were shown by calves that had received additional contact (p<0.05) than those that had received minimal contact. When the calves were loaded onto the truck, it took more time and effort to load pair housed calves than individually housed calves (p<0.01) and less effort to load calves that had received additional contact (p<0.01) compared to those that had received minimal contact. During loading additional contact calves had lower heart rates (p<0.05) than those that had received minimal contact, while during transport pair housed calves had lower heart rates compared to individually housed ones (p<0.05). For all the observations performed, no interactions were found between housing conditions and human contact.It is concluded that, compared to calves housed individually, calves housed in pairs are less ready to approach humans and less easy to handle. Providing calves with regular positive contacts makes them less fearful of people and improves handling. Due to the greater difficulty in handling calves housed in groups, it is concluded that these animals need to have regular contact with humans.     

Genetic analysis of reactivity to humans in Goettingen minipigs

Goettingen minipigs are laboratory animals with an increasing demand over the last few years. At the moment, Goettingen minipigs are not selected for a low reactivity to humans and this trait is not included in the breeding programme. However, it is obvious that there is a need for genetically non-responding minipigs during handling to facilitate the treatment and restraint of the animals which is often needed in biomedical experiments. A first testing scheme was developed to evaluate the reactivity of Goettingen minipigs to humans and to analyse whether the trait reactivity to humans can be considered in the breeding programme. In this study temperament scores of this testing scheme for nine different traits from 10,033 animals collected from 2005 to 2008 were analysed. Temperament was subjectively scored on a scale from 1 to 5 while the pig is caught (C), held on the arms (A), standing in a box for weighing (W), standing on a table (T) and walking on the ground (G). The traits were a combination of these situations evaluated at three different ages (2, 4 and 6 months). Genetic parameters were estimated using bivariate models and different possible selection strategies were examined. Heritabilities were low to moderate with a range from 0.09 to 0.22 and phenotypic and genetic correlations between the nine traits were moderate to high with phenotypic correlations between 0.12 (W2 and G4) and 0.64 (W2 and A2) and genetic correlations between 0.44 (A4 and C6) and 1.00 (e.g. W2 and A4). It was shown that the highest genetic progress per year can be obtained when all nine traits are considered in the selection index. Under an economical point of view the selection on the basis of the two arm traits plus the trait W2 should be preferred.Based on a critical discussion of the explanatory power of the used scoring system a new evaluation scheme was developed. In this scheme the minipigs can be divided into responding and non-responding animals whereas the latter are desired for selection. The suggested scoring system offers better possibilities for statistical analyses. It is planned to include the selection for non-responding Goettingen minipigs in the routine breeding programme.     

Kidney and splanchnic handling of interleukin-6 in humans

Chronic elevation of circulating Interleukin-6 (IL-6) is observed in elderly individuals as well as in several illnesses, including chronic kidney diseases. A number of cells and tissues possess the ability to metabolize significant amounts of IL-6 in vitro. However, information on signals and mechanisms by which IL-6 is removed from blood in humans is still incomplete. To assess the individual role of splanchnic organs and kidney on IL-6 inter-organ exchange we used the IL-6 mass-balance technique across the hepato-splanchnic bed and kidney in six subjects with normal renal and liver function undergoing diagnostic venous catheterizations. Both in the hepatic and renal veins IL-6 levels were significantly lower (p=0.041 and 0.038, respectively), than in the artery. The fractional extraction of IL-6, i.e., the percentage of arterial IL-6 extracted after a single pass, was greater across the splanchnic organs (18%) than across the kidney (8%). Accordingly, IL-6 plasma clearance across splanchnic organs was greater than across the kidney and the sum of kidney and splanchnic removal accounted for as much as 63% of the estimated adipocyte IL-6 release. Our data demonstrate that, although the individual contribution to removal is different, both splanchnic organs and kidneys affect in a significant way the disposal of IL-6 in humans. According, both liver and kidney dysfunction could affect the handling of this proinflammatory cytokine and favour a chronic inflammatory response.     

Relating maximum airway dilation and subsequent reconstriction to reactivity in human lungs.

Measures of airway resistance (Raw) during deep inspiration (DI) suggest that asthmatic subjects possess stiffer, more reactive airway smooth muscle. There is evidence that one can enhance airway reactivity in healthy lungs by prohibiting DI for an extended period. The present study had two goals. First, we determined whether the maximum dilation capacity of asthmatic subjects depended on the rate of the DI. Second, we investigated whether the enhanced reactivity in healthy humans might derive from additional mechanisms not present in asthmatic subjects. For the first goal, we tracked Raw in seven healthy and seven asthmatic subjects during a noncoached DI, a DI with a 5- to 10-s breath hold at total lung capacity, and a rapid DI. We found that the minimum resistance achieved at total lung capacity was independent of the manner in which the DI was performed. For the second goal, we tracked the rate of return of Raw after a DI as well as dynamic lung elastance before and after the DI, at baseline and after bronchial challenge. A drop in lung elastance post-DI would indicate reopening of lung regions and/or reduced heterogeneities. The data show that constricted healthy but not asthmatic subjects produce longer lasting residual dilation. Hence, a portion of the enhanced reactivity in a healthy subject's response to prohibition of DIs is likely due to airway closure and/or atelectasis that can be ablated with a DI. We conclude that preventing DIs does not ensure that healthy subjects will transition entirely to an asthmatic-like hyperreactive lung state.     

Total sleep deprivation alters cardiovascular reactivity to acute stressors in humans

Exaggerated cardiovascular reactivity to mental stress (MS) and cold pressor test (CPT) has been linked to increased risk of cardiovascular disease. Recent epidemiological studies identify sleep deprivation as an important risk factor for hypertension, yet the relations between sleep deprivation and cardiovascular reactivity remain equivocal. We hypothesized that 24-h total sleep deprivation (TSD) would augment cardiovascular reactivity to MS and CPT and blunt the MS-induced forearm vasodilation. Because the associations between TSD and hypertension appear to be stronger in women, a secondary aim was to probe for sex differences. Mean arterial pressure (MAP), heart rate (HR), and muscle sympathetic nerve activity (MSNA) were recorded during MS and CPT in 28 young, healthy subjects (14 men and 14 women) after normal sleep (NS) and 24-h TSD (randomized, crossover design). Forearm vascular conductance (FVC) was recorded during MS. MAP, FVC, and MSNA (n = 10) responses to MS were not different between NS and TSD (condition × time, P > 0.05). Likewise, MAP and MSNA (n = 6) responses to CPT were not different between NS and TSD (condition × time, P > 0.05). In contrast, increases in HR during both MS and CPT were augmented after TSD (condition × time, P ≤ 0.05), and these augmented HR responses persisted during both recoveries. When analyzed for sex differences, cardiovascular reactivity to MS and CPT was not different between sexes (condition × time × sex, P > 0.05). We conclude that TSD does not significantly alter MAP, MSNA, or forearm vascular responses to MS and CPT. The augmented tachycardia responses during and after both acute stressors provide new insight regarding the emerging links among sleep deprivation, stress, and cardiovascular risk.     

Effects of cumulus cells on male pronuclear formation and subsequent early development of bovine oocytes in vitro

Bovine oocytes were matured in culture with and without cumulus cells. The proportion of oocytes matured to metaphase-II 24 h after culture was not different between those matured with and without cumulus cells. When cultured oocytes were inseminated in vitro, high proportions (84 to 87%) of oocytes were penetrated, with no difference between those matured with and without cumulus cells. However, the proportion of oocytes penetrated at the male pronuclear stage was significantly higher in cumulus-intact than in cumulus-free oocytes (90 vs 31%). The proportion of oocytes cleaved beyond the 8 approximately 32-cell stage was also significantly higher in cumulus-intact than in cumulus-free oocytes. It is concluded that the cumulus cells may have an important function for normal cytoplasmic maturation of bovine oocytes in vitro.     

The role of handling in communication between humans and weanling pigs

This study examined whether regular handling influenced the behavioral response and patterns of the pigs toward a human during the progress of the treatment. Eighteen 4-week-old crossbred weanling pigs from three litters were allotted at random within litters to one of two treatments. The pigs in the handling treatment were individually identified and received regular handling from the experimenter for 15 min, three times per week for 4 weeks. Besides this treatment, the pigs in the handling treatment received brushing for 15 min, once per week for 3 weeks. The pigs in the no-handling treatment had no contact with humans apart from that received during routine husbandry. A catching test was conducted on the pigs in the handling treatment once a week for 4 weeks, and the same test was imposed on the pigs in the no-handling treatment at the start of the experiment. At the end of the experimental period, an experimenter unknown to the pigs conducted the catching test on both treatment groups. The response of the pigs toward the experimenter was classified as either approaching or avoiding behaviors. Specific transitional patterns existed in pigs' physical interaction with a human. During the progression of the handling treatment, the proportion of avoidance behavior significantly (P < 0.05) decreased and the mean aversion score also significantly (P < 0.05) decreased. The variety of physical interactions significantly (P < 0.05) increased. As a consequence, the number of interactions observed in the handling treatment was more than that of the no-handling treatment during the catching test at the end of the experiment. The pigs receiving the regular handling repeatedly tried to make frequent physical contact with the experimenter in spite of repeated chasing and catching events. In conclusion, handling pigs regularly from 4 to 7 weeks of age increases their propensity to approach humans and the variety of their interactions with a human handler, possibly by reducing their fear of humans.     

Chimpanzees empathize with group mates and humans,but not with baboons or unfamiliar chimpanzees

Human empathy can extend to strangers and even other species, but it is unknown whether non-humans are similarly broad in their empathic responses. We explored the breadth and flexibility of empathy in chimpanzees, a close relative of humans. We used contagious yawning to measure involuntary empathy and showed chimpanzees videos of familiar humans, unfamiliar humans and gelada baboons (an unfamiliar species). We tested whether each class of stimuli elicited contagion by comparing the effect of yawn and control videos. After including previous data on the response to ingroup and outgroup chimpanzees, we found that familiar and unfamiliar humans elicited contagion equal to that of ingroup chimpanzees. Gelada baboons did not elicit contagion, and the response to them was equal to that of outgroup chimpanzees. However, the chimpanzees watched the outgroup chimpanzee videos more than any other. The combination of high interest and low contagion may stem from hostility towards unfamiliar chimpanzees, which may interfere with an empathic response. Overall, chimpanzees showed flexibility in that they formed an empathic connection with a different species, including unknown members of that species. These results imply that human empathic flexibility is shared with related species.     

Effectiveness of EMG biofeedback training for controlling arousal in subsequent stressful situations

Thirty-five subjects participated in (1) a pretreatment session during which arousal was measured while subjects anticipated and then viewed a stressful film; (2) four 20-min treatment sessions during which subjects received either contingent EMG biofeedback (biofeedback treatment), instructions to attend to a variable pitch tone (attention-placebo control), instructions to relax as much as possible (instructions-only control), or instructions to sit quietly (no-treatment control); and (3) a posttreatment session that was identical to the pretreatment session. Results indicate that when compared to the subjects in the control conditions, subjects who received EMG biofeedback were not effective in reducing frontalis EMG levels during treatment or while viewing the stressful film, but they were effective in reducing frontalis EMG levels while anticipating the stressful film. There was no evidence that EMG biofeedback influenced either skin conductance or self-reports of arousal.This research was supported in part by Bio-Medical and General Research Fund grants from the University of Kansas to David S. Holmes. Appreciation is due to B. Kent Houston, Edward F. Morrow, and Charles A. Hallenbeck for their contributions to the project.     

Effects of handling aids on calf behavior

Effects of three different handling aids on calf behavior were determined. Group 1 calves were intensively-reared intact Holstein males (mean 180 days old); Group 2, extensively-reared beef-breed females (mean 230 days); Group 3, extensively-reared castrated beef-breed males (mean 253 days). Calves in each group were assigned to one of three handling aid treatments (n=5 per treatment subgroup; total n=45): electric prod (Prod), oar with rattles (Oar), manual urging (Manual). Treatments were applied only as needed to encourage forward movement of calves through the length of a solid-sided semicircular chute system. Number of treatment applications, length of time required to move through the entire chute system, and behavior during movement through the chute were recorded. An approach test was conducted 1 day before and 1 day and 1 week after chute tests to evaluate changes in behavior due to handling aid application. During chute tests, Group 1 Prod calves required the fewest treatment applications (4.9) vs. 23.5 (Oar) or 13.5 (Manual), ran most often (1.40 times) vs. 0.20 times (Manual) or 0.33 times (Oar), and made contact with chute sides most often (1.8 times vs. 0.2 times (Manual) or 0.7 times (Oar), respectively (all P<0.05). Similar trends were observed for calves in Groups 2 and 3. There were no significant differences between behaviors observed during the approach tests conducted before and after handling aid treatments had been imposed. Regardless of treatment, intensively-reared Group 1 calves appeared markedly less fearful of handlers during approach tests compared to extensively-reared calves in Groups 2 and 3, which demonstrated overt attempts to escape from the test facilities. One week after chute tests, 13 of 15 Prod calves from all three groups walked, rushed, or backed >1 m away from the handler when the prod was buzzed but not applied, suggesting that the buzzing sound alone may have sufficed to encourage movement by calves that had previously experienced both the sensation and sound associated with electric prodding.     

Effects of maternal separation, early handling, and standard facility rearing on orienting and impulsive behavior of adolescent rats

Effects of maternal separation in rats have been extensively investigated, but no studies have examined its effects in rat adolescence. We examined the effects of neonatal infant-mother separation (MS) for 6h/day and early handling (EH) for 10 days during the first 2 weeks of life by comparing MS and EH groups to standard facility reared (SFR) controls. At adolescence, the animals were evaluated in a novel and familiar open-field, the light-dark box, and the sucrose consumption test. Behavioral indices included orienting behavior (rearing frequency and duration), impulsive behavior (movement velocity and risk taking by entering the center of the open field or the light compartment of the light-dark box), hyperactivity (ambulatory distance and stereotypic movement), and reward-seeking behavior (sucrose drinking time). The prolonged MS during the first 2 weeks of life resulted in decreased orienting behavior and increased impulsive behavior in adolescence. Measures of ambulatory and stereotypic movements showed that MS rats were hyperactive in the novel environment whereas EH rats were less active overall. The impulsive/hyperactive phenotype produced by this MS protocol may provide a useful animal model to investigate the neurological basis for the similar behavioral phenotype found in attention deficit/hyperactivity disorder.