Beat Wechsler

Behaviour and leg injuries in dairy cows kept in cubicle systems with straw bedding or soft lying mats

In order to reduce straw input, soft lying mats are used increasingly instead of straw bedding in cubicle systems for dairy cows. This study aimed at comparing different types of soft lying mats with straw bedding regarding cow behaviour and leg injuries. Data were collected on five farms with straw bedding and on 13 farms using four types of soft lying mats consisting of different materials. On each farm, lying behaviour of 10 cows was recorded automatically during 3 days by means of a pneumatically operated resting sensor fitted in a belt. In addition, standing up and lying down behaviour of cows was quantified by direct observations, and all cows on a given farm were checked once for leg injuries.There were no significant differences between cows kept in cubicle systems with soft lying mats and straw bedding regarding the total time spent lying per day and the number of lying bouts per day. Standing up and lying down behaviour also did not differ between cows with access to soft lying mats and straw bedding. Leg injuries were most frequent in the tarsal and carpal joints. Cows kept in cubicle systems with soft lying mats had a significantly higher incidence of both hairless patches more than 2 cm in diameter (P<0.001) and scabs or wounds less than 2 cm in diameter (P<0.001) located in the tarsal joints than cows in cubicle systems with straw bedding. With the carpal joints, on the other hand, the incidence of leg injuries did not differ significantly between these two housing conditions. In conclusion, the results of this study indicate that soft lying mats are equivalent to straw bedding in terms of cow behaviour but less favourable with respect to leg injuries located in the tarsal joints.

The influence of climatic conditions on physiological and behavioural parameters in dairy cows kept in open stables

This study aimed to assess whether cows are able to cope with the range of climatic conditions they are exposed to in open stables on commercial farms in central Europe. On each of four farms, ten lactating cows were observed over a total of five weeks in winter, spring and summer. Based on continuous measurements of air temperature (–13·8 to 28·7oC) and relative air humidity (0·26 to 0·99), a mean value of a temperature humidity index (THI) was calculated for each farm and each observation day for night and day. THI had significant effects on skin temperature and body surface temperature (infra-red thermography) both during night and day. Rectal temperature, duration of lying and cortisol concentration in the milk was significantly affected by THI during the day but not during the night. Heart rate and frequency of lying did not significantly covary with THI. Differences between farms and interactions between THI and farm were significant for most parameters. These results suggest that the climatic conditions during the day induced stronger thermoregulatory responses than the conditions during the night. Within the measured range of climatic conditions the cows were hardly exposed to severe cold or heat stress.

Behavioural and physiological assessment of positive and negative emotion in sheep

The assessment of emotional states in animals, particularly positive ones, remains a scientific challenge. We investigated differences in behavioural and physiological measures recorded in sheep, Ovis orientalis aries, during situations likely to coincide with negative, intermediate and positive emotional valence. Reactions of 15 sheep were observed during separation from group members (negative valence), standing in the feeding area (intermediate valence) and being voluntarily groomed by a familiar human (positive valence). Several ear postures, relative eye aperture, cardiorespiration and body surface humidity and temperature were recorded continuously for up to 4 min in each experimental situation. Data were analysed using linear mixed-effects models, and correlations were calculated between ethophysiological measurements. Groomed sheep showed few ear posture changes, low proportions of forward ear postures, low relative eye aperture and a low variance in body surface humidity. The values of most of these measures increased linearly towards standing in the feeding area and further towards separation from group members. Conversely, groomed sheep showed high proportions of axial ear postures, long mean interheartbeat intervals and high heart rate variability, with values declining linearly towards the negative situation. In addition, behavioural and cardiac measurements correlated moderately to strongly. In conclusion, emotional valence in sheep could be differentiated by both behavioural and physiological measures. Based on our data, it may be possible to replace some physiological measures with observations of ear postures. The findings provide valuable insights for assessing both negative and positive emotion in animals, which can help to promote positive experiences in captive housing conditions.

A comparison of the behaviour of domestic chicks reared with or without a hen in enriched pens

Abstract Studies on the behaviour of domestic chicks raised by a hen suggest that the hen has a major influence on the development of pecking preferences in the chicks. The absence of a hen for commercially reared chicks could therefore be crucial for the development of feather pecking. In the present study, it was tested experimentally whether the presence of a hen has a significant effect on the incidence of feather pecks in laying hen chicks (white ‘Lohman Selected Leghorn’ hybrids). Groups of eight chicks were reared with a hen (five groups) or without a hen (seven groups) in enriched pens over the first 8 weeks after hatching. There was a synchronization in the behaviour of the hen and the chicks both with respect to the activity performed (resting, exploring, feeding, preening) and the pen area used at a given moment. Chicks raised by a hen spent significantly more time feeding, less time standing and less time on the perches than chicks housed without a hen. Flight responses were significantly more frequent in chicks reared without a hen. There was no significant difference in the rate of feather pecking interactions between chicks reared with and without a hen. In both rearing conditions, the chicks already started to peck at the feathers of conspecifics in the first week of life. It is concluded that the presence of a hen does not prevent the chicks from directing pecks at the feathers of conspecifics and that factors other than the absence of a hen must be crucial for the occurrence of serious problems with feather pecking in commercial housing systems for laying hen chicks.

Reduction in cross-sucking in calves by the use of a modified automatic teat feeder

Cross-sucking may be a problem in group-housed calves fed by automatic teat feeders. In the present study, the behaviour of calves fed by a conventional feeder with an open feeding stall (n=15 calves) was compared with the behaviour of calves fed by a modified feeder, closing in the rear after the calf has entered (n=14 calves). It was found that the calves fed by the feeder with the closed stall stayed longer in the feeding stall following milk ingestion (P<0.001), showed longer bouts of non-nutritive sucking directed to the teat after milk ingestion (P<0.005) and performed less cross-sucking in the first 15min after milk ingestion (P<0.001) than calves fed by the feeder with the open stall. The design of the feeder had, however, no significant influence on the incidence of cross-sucking performed without close temporal association with milk ingestion. As the modification in the feeding stall reduces cross-sucking and is not costly, it should be feasible to introduce it in practice.

In vivo functional near-infrared spectroscopy measures mood-modulated cerebral responses to a positive emotional stimulus in sheep

The affective state of an animal, which is thought to reflect its welfare, consists of both short-term emotional reactions and long-term general mood. Because this state is generated and processed by the brain, we used non-invasive measurement of such brain activity as a novel indicator variable and investigated the interplay of mood and short-term emotional reactions in animals. We developed a wireless sensor for functional near-infrared spectroscopy (fNIRS), which assesses cortical perfusion changes, and consequently neuronal activity. Mood differences were induced by barren and enriched housing in a total of nine sheep and we observed their brain reaction in response to the positive situation of being groomed. We detected a decrease in cerebral oxyhaemoglobin concentration ([O(2)Hb]) which persisted during grooming. The localisation of the decrease in the brain did not depend on the site where the stimulus was applied. Also, the intensity of the response did not depend on the intensity of the grooming stimulus and a sham stimulus did not evoke an [O(2)Hb] response as seen with a grooming stimulus. Thus, we conclude that the observed haemodynamic brain response was unlikely to reflect pure somato-sensory information. We then found that the amplitude of the [O(2)Hb] response was larger if sheep were in a supposedly more negative mood. This contradicts the common assumption that negative mood generally taints reactions to emotional stimuli. Our results also demonstrate the potential of fNIRS for assessing affective states in freely moving animals.

Valence of physical stimuli, not housing conditions, affects behaviour and frontal cortical brain activity in sheep

Modulation of short-term emotions by long-term mood is little understood but relevant to understand the affective system and of importance in respect to animal welfare: a negative mood might taint experiences, whilst a positive mood might alleviate single negative events. To induce different mood states in sheep housing conditions were varied. Fourteen ewes were group-housed in an unpredictable, stimulus-poor and 15 ewes in a predictable, stimulus-rich environment. Sheep were tested individually for mood in a behavioural cognitive bias paradigm. Also, their reactions to three physical stimuli thought to differ in their perceived valence were observed (negative: pricking, intermediate: slight pressure, positive: kneading). General behaviour, activity, ear movements and positions, and haemodynamic changes in the cortical brain were recorded during stimulations. Generalised mixed-effects models and model probabilities based on the BIC (Bayesian information criterion) were used. Only weak evidence for mood difference was found. Sheep from the unpredictable, stimulus-poor housing condition had a somewhat more negative cognitive bias, showed slightly more aversive behaviour, were slightly more active and moved their ears somewhat more. Sheep most clearly differentiated the negative from the intermediate and positive stimulus in that they exhibited more aversive behaviour, less nibbling, were more active, showed more ear movements, more forward ear postures, fewer backward ear postures, and a stronger decrease in deoxyhaemoglobin when subjected to the negative stimulus. In conclusion, sheep reacted towards stimuli according to their presumed valence but their mood was not strongly influenced by housing conditions. Therefore, behavioural reactions and cortical brain activity towards the stimuli were hardly modulated by housing conditions.

A sequential analysis of eliminative behaviour in domestic pigs

Knowledge of eliminative behaviour in pigs is of much importance for the design of housing systems in order to minimise soiling of the lying area. In the present study, piglets, fatteners, finishers and sows were observed as focal animals at regularly used dunging areas in a highly structured housing system (Family Pen System). A total of 53, 136, 272 and 277 focal animal samples, respectively, of the four categories of animals were included in the analysis. Statistically significant transitions (P < 0.0025) between behavioural elements were identified by means of a sequential analysis. The typical sequence of behavioural elements was as follows: Enter dunging area, sniff, posture, defaecate/urinate, sniff. Both for defaecation and urination the percentage of sniffs classified as ‘close to wall’ was significantly higher before than after eliminative behaviour whereas the percentage of sniffs classified as ‘close to floor’ was significantly lower before than after eliminative behaviour. Our results show that sniffing behaviour is temporally associated with eliminative behaviour in pigs.

Frontal brain deactivation during a non-verbal cognitive judgement bias test in sheep.

Animal welfare concerns have raised an interest in animal affective states. These states also play an important role in the proximate control of behaviour. Due to their potential to modulate short-term emotional reactions, one specific focus is on long-term affective states, that is, mood. These states can be assessed by using non-verbal cognitive judgement bias paradigms. Here, we conducted a spatial variant of such a test on 24 focal animals that were kept under either unpredictable, stimulus-poor or predictable, stimulus-rich housing conditions to induce differential mood states. Based on functional near-infrared spectroscopy, we measured haemodynamic frontal brain reactions during 10 s in which the sheep could observe the configuration of the cognitive judgement bias trial before indicating their assessment based on the go/no-go reaction. We used (generalised) mixed-effects models to evaluate the data. Sheep from the unpredictable, stimulus-poor housing conditions took longer and were less likely to reach the learning criterion and reacted slightly more optimistically in the cognitive judgement bias test than sheep from the predictable, stimulus-rich housing conditions. A frontal cortical increase in deoxy-haemoglobin [HHb] and a decrease in oxy-haemoglobin [O2Hb] were observed during the visual assessment of the test situation by the sheep, indicating a frontal cortical brain deactivation. This deactivation was more pronounced with the negativity of the test situation, which was reflected by the provenance of the sheep from the unpredictable, stimulus-poor housing conditions, the proximity of the cue to the negatively reinforced cue location, or the absence of a go reaction in the trial. It seems that (1) sheep from the unpredictable, stimulus-poor in comparison to sheep from the predictable, stimulus-rich housing conditions dealt less easily with the test conditions rich in stimuli, that (2) long-term housing conditions seemingly did not influence mood--which may be related to the difficulty of tracking a constant long-term state in the brain--and that (3) visual assessment of an emotional stimulus leads to frontal brain deactivation in sheep, specifically if that stimulus is negative.

Identification of key nest site stimuli for Japanese / quail Coturnix japonica

Abstract For both egg production and laboratory research, Japanese quail ( Coturnix japonica ) are typically housed in battery cages without nest boxes. In such cages the quail hens show symptoms of pre-laying restlessness. The inability to perform normal pre-laying behaviour is regarded as one of the most important problems for the welfare of caged laying hens. The present study aimed at identifying key nest site stimuli for quails, to enable nest boxes to be designed for alternative housing systems. Groups of hens were kept in pens containing litter, nest boxes and dustbathing boxes. The type of nest box was varied between pens, and the incidence of eggs laid outside the nest boxes (floor-eggs) was recorded over periods of 15 days. In experiment 1 (8 groups of 30 hens), both the nature of the top of the nest boxes (closed or with slits) and the type of substrate in the nest boxes (artificial turf or hay) had a significant effect on the percentage of floor-eggs. Nest boxes with a top with slits and filled with hay were best accepted for laying. Nest boxes situated in the corners of the pens were significantly selected more often for egg laying than more central nests. In experiment 2 (8 groups of 14 hens), neither the nature of the sides of the nest boxes (closed or with slits) nor the colour of the nest boxes (green or brown) had a significant effect on the incidence of floor-eggs. In experiment 3 (16 groups of 14 hens with 2 or 3 cocks), the percentage of floor-eggs was significantly lower in pens with high (170 lux) than with low (15 lux) light intensity. There was also a tendency for nest boxes filled with chaff to be better accepted than nest boxes filled with hay. In experiments 2 and 3, in pens with floors half litter and half of perforated plastic more floor-eggs were found on the litter. Few eggs were laid in the dustbathing boxes in any experiment. This study shows that Japanese quail lay up to 90% of eggs in nest boxes provided these are properly designed. It should therefore be feasible to develop housing systems with nests for Japanese quail which may replace conventional battery cages.