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.     

Housing conditions differentially affect physiological and behavioural stress responses of zebrafish, as well as the response to anxiolytics

Zebrafish are a widely utilised animal model in developmental genetics, and owing to recent advances in our understanding of zebrafish behaviour, their utility as a comparative model in behavioural neuroscience is beginning to be realised. One widely reported behavioural measure is the novel tank-diving assay, which has been often cited as a test of anxiety and stress reactivity. Despite its wide utilisation, and various validations against anxiolytic drugs, reporting of pre-test housing has been sparse in the literature. As zebrafish are a shoaling species, we predicted that housing environment would affect their stress reactivity and, as such, their response in the tank-diving procedure. In our first experiment, we tested various aspects of housing (large groups, large groups with no contact, paired, visual contact only, olfactory contact only) and found that the tank diving response was mediated by visual contact with conspecifics. We also tested the basal cortisol levels of group and individually housed fish, and found that individually housed individuals have lower basal cortisol levels. In our second experiment we found ethanol appeared to have an anxiolytic effect with individually housed fish but not those that were group housed. In our final experiment, we examined the effects of changing the fishes' water prior to tank diving as an additional acclimation procedure. We found that this had no effect on individually housed fish, but appeared to affect the typical tank diving responses of the group housed individuals. In conclusion, we demonstrate that housing represents an important factor in obtaining reliable data from this methodology, and should be considered by researchers interested in comparative models of anxiety in zebrafish in order to refine their approach and to increase the power in their experiments.     

Cooperative social coordination and aggression in male laboratory rats: effects of housing and testosterone

A cooperative behavior, coordinated shuttling by pairs of laboratory rats in a rectangular chamber, can be influenced strongly by an interaction between housing and sex. Males and females learn readily when housed together socially, but individual housing ("isolation") causes severe deficits selectively in males. The aim of the present study was to examine the role of testosterone in the differential effects of housing on cooperation learning. Males of a Sprague-Dawley derived strain were housed socially or individually and treated daily in one of three ways (six groups, n = 6 per group): (1) castrated, injected with oil vehicle (without testosterone); (2) castrated, injected with 500 micrograms testosterone propionate (exogenous TP); and (3) sham operated, injected with oil (intact, endogenous testosterone). Socially housed pairs learned readily in all treatment groups, using strategies of coordination in which stereotyped contact or aggressive interactions were interpolated. Individual housing was associated with a deficit, but only in the TP-treated and intact groups in which some pairs either did not learn or performed poorly. The deficit was associated with violent fighting and extreme and stable differentiation into dominants and subordinates, the latter exhibiting prolonged freezing. Oil-treated castrates, when housed individually, were unimpaired and actually surpassed their socially housed counterparts on some measures. Their success was associated with an increase only in low-level aggression. The housing-hormone interaction in male rats suggests that testosterone influences the capacity to develop cooperative behavior by modulating both aggression and its consequences for the relationship between partners. The use of social interaction models, including cooperation, for the study of behavior-hormone interactions was also discussed.     

Enhancement of performances in a learning task in suckler calves after weaning and relocation: Motivational versus cognitive control?: A pilot study

Weaning in suckler calves influences performance in a learning task. The aim of the present study was to investigate whether the improved performance after weaning, including relocation, is due to differences in motivation for the reward or in learning abilities. Forty Aubrac calves were used; half of them were weaned from their dams at around eight months, the other half were weaned one month later. After weaning, calves were housed in groups of four in a new setting. From the day after weaning of the last group of calves, the animals were subjected to two tests: (1) an arena test, (2) a T-maze test where one arm led to either a social or a food reward. The T-maze test consisted of three sessions: in Session 1, trials were conducted until the animal acquired the task (i.e. did not take the unrewarded arm on three consecutive trials); in Session 2, the motivation for the reward was assessed via the walking time of the animal to reach the reward; in Session 3, the place of reward was reversed and the animals were trained until they acquired the new task.

Calves weaned for one day explored more (P < 0.05) and had lower heart rates during the arena test (P < 0.05) compared to the ones weaned for one month. During the T-maze test, calves weaned for one month versus one day did not differ in their capacities to learn the initial route (Session 1) or in their motivation for either the social or food reward (Session 2). Calves weaned for one day learned significantly faster (P < 0.05) the reversed route (Session 3) than calves weaned for one month. Hence, the better performances at reversal in the T-maze by calves that have just been weaned cannot be accounted for by a higher motivation for the reward. A better cognitive control of their behaviour due to a lower stress state is suggested by our results.     

The presence of the dam during handling prevents the socialization of young calves to humans

The effect of handling and hand-feeding of calves with or without their dams present on the calves’ subsequent response to humans was investigated using 5 groups of 10 Danish Friesian calves, each of which received a different treatment. The treatments were: calf separated from its dam immediately after birth, housed in a single pen and handled (group SH) or not handled (group S) calf adjacent to cow and handled (group CH) or not handled (C) for the first 4 days after calving. The fifth group was housed together with their dams for the first 4 days of life and then moved to single pens and handled there for the next 4 days (group C-SH). The handling treatment was carried out three times daily for 4 days and consisted of 6 min of hand-feeding with milk from a teat-bucket and patting, stroking and talking to the calf. After separation, all calves were housed in single pens. Human contact was minimised except during the treatment periods.

The approach behaviour of each calf to an unknown person was tested at days 20, 40 and 55 in their home pen. Flight distance was determined at day 55. The test at day 55 was carried out in a large single pen where the calves had been housed for 24 h prior to the test. The latency to interact (in seconds) with the person was significantly shorter (P<0.001) in all three tests for SH (13±5, 29±7 and 44±8, at days 20, 40 and 55, respectively) and C-SH (28±6, 47±17 and 70±17) compared to S (240±25, 238±33 and 173±5), C (240±28, 202±36 and 167±13) and CH (233±36, 271±29 and 128±19). The results of the latter three groups did not differ significantly. Treatment also affected the position and the orientation of the calf in the pen during the tests. Calves in SH and C-SH stood at the front of the pen and faced the person more often than calves in S, C and CH. Again, there were no significant differences between the results of the latter three groups.

The results indicate that the presence of the dam limits the effect of the handling treatment on young calves’ motivation to interact with humans. It is likely that primary socialization occurs with the dam, preventing a secondary socialization developing with humans, until the calf is isolated from the dam.     

Behavioral flexibility in a mouse model for obsessive‐compulsive disorder: Impaired Pavlovian reversal learning in SAPAP3 mutants

Obsessive‐compulsive disorder (OCD) is characterized by obsessive thinking, compulsive behavior and anxiety, and is often accompanied by cognitive deficits. The neuropathology of OCD involves dysregulation of cortical‐striatal circuits. Similar to OCD patients, SAPAP3 knockout mice 3 (SAPAP3^?/?) exhibit compulsive behavior (grooming), anxiety and dysregulated cortical‐striatal function. However, it is unknown whether SAPAP3^?/? display cognitive deficits and how these different behavioral traits relate to one another. SAPAP3^?/? and wild‐type (WT) littermates were trained in a Pavlovian conditioning task pairing visual cues with the delivery of sucrose solution. After mice learned to discriminate between a reward‐predicting conditioned stimulus (CS+) and a non‐reward stimulus (CS?), contingencies were reversed (CS+ became CS? and vice versa). Additionally, we assessed grooming, anxiety and general activity. SAPAP3^?/? acquired Pavlovian approach behavior similarly to WT, albeit less vigorously and with a different strategy. However, unlike WT, SAPAP3^?/? were unable to adapt their behavior after contingency reversal, exemplified by a lack of re‐establishing CS+ approach behavior (sign tracking). Surprisingly, such behavioral inflexibility, decreased vigor, compulsive grooming and anxiety were unrelated. This study shows that SAPAP3^?/? are capable of Pavlovian learning, but lack flexibility to adapt associated conditioned approach behavior. Thus, SAPAP3^?/? not only display compulsive‐like behavior and anxiety, but also cognitive deficits, confirming and extending the validity of SAPAP3^?/? as a suitable model for the study of OCD. The observation that compulsive‐like behavior, anxiety and behavioral inflexibility were unrelated suggests a non‐causal relationship between these traits and may be of clinical relevance for the treatment of OCD.     

Exposure to Folate Receptor Alpha Antibodies during Gestation and Weaning Leads to Severe Behavioral Deficits in Rats: A Pilot Study

The central nervous system continues to develop during gestation and after birth, and folate is an essential nutrient in this process. Folate deficiency and folate receptor alpha autoantibodies (FRα-AuAb) have been associated with pregnancy-related complications and neurodevelopmental disorders. In this pilot study, we investigated the effect of exposure to FRα antibodies (Ab) during gestation (GST), the pre-weaning (PRW), and the post weaning (POW) periods on learning and behavior in adulthood in a rat model. In the open field test and novel object recognition task, which examine locomotor activity and anxiety-like behavior, deficits in rats exposed to Ab during gestation and pre-weaning (GST+PRW) included more time spent in the periphery or corner areas, less time in the central area, frequent self-grooming akin to stereotypy, and longer time to explore a novel object compared to a control group; these are all indicative of increased levels of anxiety. In the place avoidance tasks that assess learning and spatial memory formation, only 30% of GST+PRW rats were able to learn the passive place avoidance task. None of these rats learned the active place avoidance task indicating severe learning deficits and cognitive impairment. Similar but less severe deficits were observed in rats exposed to Ab during GST alone or only during the PRW period, suggesting the extreme sensitivity of the fetal as well as the neonatal rat brain to the deleterious effects of exposure to Ab during this period. Behavioral deficits were not seen in rats exposed to antibody post weaning. These observations have implications in the pathology of FRα-AuAb associated with neural tube defect pregnancy, preterm birth and neurodevelopmental disorders including autism.     

Effects of early separation on the dairy cow and calf: 2. Separation at 1 day and 2 weeks after birth

This study investigated the effects of separating dairy calves from their mothers at 1 day (early separation) and 14 days (late separation) after birth. Behavioural observations were conducted on 24 Holstein dairy cow–calf pairs during the first 24 h after separation. Before separation, cow–calf pairs were generally inactive. After separation, cows from the late-separation treatment group showed higher rates of calling, movement and placing the head outside the pen, than cows in the early-separation group. Parity did not influence cow behaviour. During the first 2 weeks after calving, cows in the late-separation group (i.e. still with their calves) yielded less milk at milking, a difference at least partly due to the milk consumed by the calf. Milk yields from days 15–150 did not differ between the two groups. After separation, calves in the late-separation group moved and placed their heads outside the pen more often than early-separation calves. During the first 14 days after birth, late-separation calves gained weight at more than three times the rate of those separated early. When introduced to an unfamiliar calf at 6 weeks of age, calves from the late-separation group showed more intense social behaviour towards the unfamiliar calf than did those calves separated early. Thus, the response to separation by both cows and calves increased when calves were separated at 2 weeks rather than 1 day of age, but calves separated at the later age gained more weight and delayed separation appeared to influence the development of calf social behaviour.     

Effect of Group vs. Single Housing on Phenotypic Variance in C57BL/6J Mice

Objective: To determine if group housing affects the variance of body composition parameters in a highly inbred mouse strain. Research Methods and Procedures: Thirty 3‐week‐old male C57BL/6J mice were obtained from the Jackson Laboratory. Fifteen mice were housed individually, and 15 mice were housed in groups of 5/cage. Animals were fed ad libitum and maintained in the same room under a 12:12‐hour light/dark photoperiod at 22 °C for 9 weeks. Animals were killed, and fat mass, soft‐lean tissue mass, bone mineral density (BMD), and bone mineral content (BMC) were determined by DXA. At necropsy, weights of the paired epididymal fat pads, paired retroperitoneal fat pads, right inguinal fat pad, liver, kidneys, paired testes, and seminal vesicles were obtained. Results: Relative to mice housed singly, group‐housed mice showed significantly greater variance in percentage of body fat, testes weight, and BMC. Group‐housed mice tended to show greater variance in liver weights and BMD. Mice housed singly were smaller, had less soft‐lean tissue mass and BMC, and lower BMD when compared with group‐housed mice. Discussion: These results suggest that with respect to body composition parameters, mice housed singly are more similar to one another than are group‐housed mice, most likely because of a reduction in environmental (predominately behavioral/social) effects. Thus, mice housed singly may be more representative of genotypic effects on body composition than group‐housed mice. Whether other inbred strains of mice show similar responses to housing condition is unknown.     

Lack of Virus Transmission from Bovine Viral Diarrhoea Virus Infected Calves to Susceptible Peers

None of 14 calves not previously exposed to BVDV became infected after being forced to have nose-to-nose contact with a group of 5 calves primarily infected with BVDV These were 5 male calves primarily infected with a type I BVDV strain, after nose-to-nose contact with a persistently viraemic calf. All 5 became infected and were clinically affected. They were slightly depressed and pyretic at 8–9 days postinfection, with a body temperature of up to 41.6°C, but no medical treatment was required. Seroconversions to BVDV were detected in these calves at 14 to 21 days postinfection. The 14 healthy calves, proved to be free from BVD virus – as well as antibodies, were introduced 2 by 2 into the group of 5 primarily infected calves on days 4, 7, 14, 21, 28, 35 and 42 after the 5 calves had been in contact with the persistently BVDV-infected calf. Each pair of calves stayed within the primarily infected group for 2 days. None of these 14 calves seroconverted to BVDV.     

Comparison of effects of four weaning methods on health and performance of beef calves

Weaning of beef calves is a stressful event that negatively impacts health and performance. A variety of interventions have been proposed to reduce stress and improve gains following weaning. This study used 288 7- to 8-month-old calves from two separate locations, to examine four different weaning strategies, as well as the impact of shipment. Calves were blocked by weight and sex, and then randomly assigned to one of four treatments: abrupt weaning (AW), where calves were separated from the dam on day 0 (D0) and allowed no further contact with the dam; fence line (FL), where calves were weaned on D0 but had fence line contact with dams for 7 days; nose flap (NF), where on day -6 calves received a nose flap that interferes with suckling, then had the flap removed and were weaned from the dam on D0; and intermittent separation (SEP), where calves were removed from dams for 24-h intervals on day -13 and day -6, then weaned on D0, but allowed fence line contact with the dam for 7 days. Each treatment group was further divided into two subgroups, one of which was shipped early (D0 for AW, day 7 for others) or shipped later (day 28). Body weight and sickness were recorded for all groups. Results showed a negative impact on gain for early shipping compared to later shipping, and poorer gain in AW calves than most other treatments. Results of the analyses of morbidity were inconclusive. This study found that delayed shipment following FL weaning improves performance under common management conditions for the US cow–calf industry.     

Play behaviour in group-housed dairy calves, the effect of space allowance

In dairy calves kept in pens, lack of sufficient space may inhibit the performance of play behaviour. The present study investigated, firstly, if an increase in space allowance increases the occurrence of play behaviour, and secondly, if calves kept at a low space allowance perform more locomotor play when released individually in a large novel area. A total of 96 dairy calves in six repetitions were housed in groups of four, in pens of either 4, 3, 2.2 or 1.5 m(2) per calf from 2 weeks of age. The occurrence of play behaviour in the home environment was recorded continuously for each individual calf during 24 h at 5, 7 and 9 weeks of age. Locomotor play decreased over the weeks (54, 29 and 19 s for weeks 5, 7 and 9, respectively; F(2,40)=17.98; P<0.001), and the interaction between space allowance and week tended to be significant (F(6,40)=1.96; P<0.10). At 5 weeks of age, calves kept at 4 or 3 m(2) per calf performed more locomotor play in the home environment than calves at 2.2 or 1.5 m(2) per calf (68, 74, 38 and 39 s for 4, 3, 2.2 and 1.5 m(2) per calf, respectively; F(3,15)=3.40; P<0.05), but in weeks 7 and 9, no effects of space allowance were found. In addition, the duration of locomotor play was recorded for all calves during an individual 10-min open-field test in a 9.6x4.8 m arena at 4 and 10 weeks of age. During the open-field test at 10 weeks of age, calves from pens with 1.5 m(2) per calf performed more locomotor play than calves on the remaining treatments (10, 9, 12 and 25 s for 4, 3, 2.2 and 1.5 m(2) per calf, respectively; F(3,15)=4.05; P<0.05). The present study shows that an increase in the available space increases the occurrence of locomotor play in the home environment at 5 weeks of age. It also shows that calves kept in pens with the smallest space allowance performed more locomotor play behaviour when released in a large arena at 10 weeks of age.     

Milking- and suckling-induced secretion of oxytocin and prolactin in parturient dairy cows

Serum concentrations of prolactin were unaffected by either suckling or milking on Day 2 or 3 postpartum in cows housed with their calves following parturition. In contrast, among cows housed without their calves milking elicited a four- to sixfold increase in serum prolactin concentrations. Serum oxytocin levels increased in response to both suckling and milking among cows housed with their calves with suckling being a more potent stimulus (257 ± 32 vs 189 ± 23 pg/ml at peak). However, the greatest increase in oxytocin levels accompanied milking in cows housed without their calves (375 ± 36 pg/ml at peak). These results suggest that stimuli associated with the presence or the absence of the calf can alter maternal secretion of oxytocin and prolactin. Greater understanding of factors which regulate secretion of these hormones may result in techniques to modify milk synthesis and milk ejection in dairy cows.     

The ecology of Escherichia coli in calves reared as dairy-cow replacements

A continual turn-over in the strains forming the majority of faecal Escherichia coli flora was demonstrated in 16 calves reared as dairy cow replacements. The incidence of antibiotic resistance among isolates, as measured by an Antibiotic Resistance Index (ARI), changed markedly with the age of the calf. The value was low initially, when the calves were 1–2 days old and housed with adult animals. It then rose rapidly during the first week after the animals had been weaned and moved into nursery pens. This change in ARI was associated with the isolation of strains resistant to four or five of the six drugs included in the sensitivity test. The ARI then fell from the third week to low levels by the time that the calves were five months of age. This fall was due to the isolation of an increasing proportion of sensitive E. coli strains. These differed from the sensitive strains which had colonized the calves in the early days of life so demonstrating that the change was not due to the reemergence of strains identified several weeks previously. The source of E. coli strains was presumed to be the calfs' environment but further investigations are required to prove this conclusively.     

Using contact logging devices to explore animal affiliations: Quantifying cow–calf interactions

Understanding animal affiliations has important implications for determining social interactions; an example is maternal interactions within beef production systems. The objective of this study was to test whether contact loggers could be used to identify cow–calf pairs. Fifty-two pairs of Belmont Red cows with calves that were between 1- and 14-days old, were fitted with contact logging devices for 1 week in groups ranging in size from five to nine pairs of cows and calves. The contact logging devices recorded the duration of contacts that were less than 7 m distance between individual animals in the group. There was a highly significant difference in both contact duration and contact frequency between cows and their own calves and cows and all other calves. It is concluded that contact logging devices have the potential to provide useful data on animal affiliations.     

The effects of conditioning to suckling, milking and of calf presence on the release of oxytocin in dairy cows

The aim of the study was to record the oxytocin (OT) release during milking (M) without or with calf presence, suckling (S) and finally calf removal just before the next milking in cows during postpartum or early lactation periods. Furthermore, the release of OT was examined during S and M in unknown surroundings (parlour). A total of 20 Brown Swiss cows kept under loose housing environment were used in our experiment. In both periods, the cows were milked twice daily at 07.00 and 18.00h and suckled three times daily at 09.00, 14.00 and 20.00h in the stall (tie housing). In the postpartum period, 13 cows were suckled and milked in the presence of their calves in the stall for the first 5 days of postpartum. Five from seven primiparous cows were additionally suckled by their own calves in the parlour on day 5 at 20.00h. On day 6, calves were separated and moved from mothers to the calf barn 10min before morning M. After evening milking cows were relocated to the herd within the same stable and milked in the parlour for a period of 4 weeks without contact to their calf. For control, additional seven primiparous cows without calf presence (not suckled) were also milked in the tie housing. In the early lactation period, suckled cows were moved back to the tie housing 2 days before the start of two consecutive days of S by their own calves and milking. Afterwards, 10min before M calves were separated again. Before S, two consecutive M were considered as controls. Results: The S stimulus during postpartum resulted in a higher OT release as compared with M in the calf presence and M after calf separation but not during M of not suckled cows. S in parlour reduced OT release. However, when not suckled primiparous cows were first milked in parlour, OT release was more reduced and in some cows total inhibition was observed. In early lactation during the first S, release of OT was lower than during control M, but increased gradually with repeated S and reached a maximum already on the second day. After two S, during evening M, the M related OT release was reduced as compared with controls. Calf removal 10min before M reduced OT release as compared with control M or M in calf presence. In conclusion, the calf presence and its removal can negatively influence OT secretion during M. Conditioning to machine milking caused a short-term reduction of OT release during first suckling, which normalised within 1 day.     

Emergency rabies control in a community of two high-density hosts

Background

Mortality and morbidity are hardly documented in the white veal industry, despite high levels of antimicrobial drug use and resistance. The objective of the present study was to determine the causes and epidemiology of morbidity and mortality in dairy, beef and crossbred white veal production. A total of 5853 calves, housed in 15 production cohorts, were followed during one production cycle. Causes of mortality were determined by necropsy. Morbidity was daily recorded by the producers.

Results

The total mortality risk was 5,3% and was significantly higher in beef veal production compared to dairy or crossbreds. The main causes of mortality were pneumonia (1.3% of the calves at risk), ruminal disorders (0.7%), idiopathic peritonitis (0.5%), enterotoxaemia (0.5%) and enteritis (0.4%). Belgian Blue beef calves were more likely to die from pneumonia, enterotoxaemia and arthritis. Detection of bovine viral diarrhea virus at necropsy was associated with chronic pneumonia and pleuritis. Of the calves, 25.4% was treated individually and the morbidity rate was 1.66 cases per 1000 calf days at risk. The incidence rate of respiratory disease, diarrhea, arthritis and otitis was 0.95, 0.30, 0.11 and 0.07 cases per 1000 calf days at risk respectively. Morbidity peaked in the first three weeks after arrival and gradually declined towards the end of the production cycle.

Conclusions

The present study provided insights into the causes and epidemiology of morbidity and mortality in white veal calves in Belgium, housed in the most frequent housing system in Europe. The necropsy findings, identified risk periods and differences between production systems can guide both veterinarians and producers towards the most profitable and ethical preventive and therapeutic protocols.     

The effect of early human contact and the separation method from the dam on responses of beef calves to humans

The objectives of this experiment were to evaluate the effect of early human contact and of the separation method from the dam on the future relationships of calves with humans, and to investigate the relationship between dam responses and calf responses. Thirty-three Salers calves aged 2–4 days old and reared outdoors were split into 3-week treatments balanced according to sex and birth dates. Group 1 (long separation from the dam and human contact: LS + H; n = 11) underwent 8 h of separation from the dam per day and 5 min of individual stroking; group 2 (short separation from the dam and human contact: SS + H; n = 11) underwent 1 h of separation and the same amount of human contact as LS + H calves. Group 3 (short separation from the dam and no human contact: SS − H; n = 11) was a control group undergoing the same duration of separation as SS + H but without stroking. At 3, 15 and 45 weeks of age, the calves were tested in a standard arena test (AT) where they were successively left alone (2 min), left with a stationary human (5 min), and left with a human approaching and touching them (2 min). At 15 and 45 weeks, the calves were also tested with the standard docility test (DT: test of restraint). The dams were also tested with DT 2 months before calving. Data analysis via Mann–Whitney tests and Spearman's correlations showed no significant effect of the duration calves were separated from their dams. Just after treatment at 3-week of age, calves given stroking (LS + H and SS + H) were more motionless and more willing to accept human contact (AT: touching) than control calves (SS − H, P < 0.01). At 45 weeks of age, calves given stroking spent also significantly more time (P < 0.05) motionless with the approaching human compared to non-stroked calves (SS − H), suggesting a persistent effect. However, this effect was not reproduced on the other behavioural criteria recorded (e.g., duration of human contact or docility score). In the different tests and at the different ages, the docility scores of the dams were significantly correlated (up to 0.7, P < 0.01) with behaviour towards humans shown by stroked calves but not non-stroked calves (SS − H). Our results suggest that additional human contact at early age, but not duration of the separation from the dam, could be beneficial for the human–animal relationship, but only for calves born to docile dams.     

Feeding behaviour and activity as early indicators of disease in pre-weaned dairy calves

Across the industry, there is large variation in health status of dairy calves and as a result, disease incidence and antibiotic use is high. This has significant implications for animal welfare, productivity and profitability of dairy and dairy-beef production systems. Technology-based early detection systems could alleviate these issues; however, methods of early detection of disease in dairy calves have not been widely explored. This study aimed to determine whether changes in activity and feeding behaviour can be used as early warning indicators of respiratory disease in calves. In total, 100 pre-weaned male Holstein calves (age: ~ 8−42 days) were used. Calves were group-housed and provided with starter diet, straw bedding and ad libitum water. Calves were fed milk replacer ad libitum through an automatic calf feeder, and each calf was fitted with a leg-mounted activity monitor. Daily activity and feeding behaviour variables were calculated for each calf. Each calf was assessed daily using a modified version of the Wisconsin Scoring System to assess respiratory disease status. Calves were classed as ‘Diseased’, ‘Intermediate’ or ‘Healthy’ based on their cumulative health score. The peak day of the most extreme illness event was identified for each calf. Data from Diseased and Healthy calves were paired for analysis based on age and BW. Data were compared for the day of peak illness, and for the 3 days previous and post. Compared to healthy calves, diseased calves lay for longer and tended to have longer lying bouts (daily lying: 17.6 ± 0.3 vs 16.7 ± 0.2 h, P < 0.01; bout length: 74.8 ± 10.6 vs 56.0 ± 3.7 min, P = 0.09 for diseased and healthy calves, respectively). Diseased calves fed for a shorter time and had fewer feeder visits (with intake) each day compared to healthy calves (feeding time (min): 19.3 ± 1.4 vs 22.8 ± 1.5; P < 0.05; visits: 2.1 ± 0.2 vs 3.2 ± 0.4; P < 0.05). Importantly, differences between diseased and healthy calves were evident in both activity and feeding behaviour on the days prior to the peak day of disease. Lying bout length was greater in diseased calves for the 2 days prior to the peak day (P < 0.05), lying time was longer on day − 1 (P < 0.05) and feeder visits with milk intake were less frequent on day − 3 (P < 0.05). Thus, measurement of feeding and activity using precision technology within early detection systems could facilitate early intervention and optimized treatment.     

Learning and owner-stranger effects on interspecific communication in domestic dogs (Canis familiaris)

Domestic dogs are very successful at following human cues like gazing or pointing to find hidden food in an object choice task. They solve this kind of situation at their first attempts and from early stages of their development and perform better than wolves. Most of the authors proposed that these abilities are a domestication product, and independent from learning processes. There are few systematic studies on the effects of learning on dogs’ communicative skills. We aim to evaluate the effect of extinction and reversal learning procedures on the use of the pointing gesture in an object choice task. The results showed that dogs stopped following the pointing cue in the extinction and that they learned to choose the not pointed container in the reversal learning. Results suggest that instrumental learning plays an important role in interspecific communication mechanisms between humans and dogs. In both experiments for half of the subjects the pointer was the owner and for the rest was a stranger. A differential effect was found: extinction was slower but reversal learning was faster when the owner gave the cue. This data indicates that the relationship of the dog with the person who emits the cue influences performance.