Previous handling and gentle interactions affect behaviour and heart rate of dairy cows during a veterinary procedure.

Posted in: Welfare by admin on January 1, 2004 | No Comments

Animals often display behavioural and physiological stress responses during routine veterinary and management procedures. These responses can be dangerous to the animals and humans and might lower welfare and performance. The effects of previous positive handling and of gentle interactions during rectal palpation and a sham insemination on the behaviour and heart rate of dairy cows were investigated. Two groups of 10 cows each were studied. One group received positive handling for four weeks in addition to routine handling by one handler. The second group only received routine handling by different caretakers. Following the handling period, each cow received a rectal palpation on four days under four different situations: cow is alone, with the handler, with a usual caretaker, or with an unknown person. Lower heart rates, less kicking, and the tendency for less restless behaviour were found among cows that had experienced the positive handling. Gentle interactions during the test also calmed the cows. However, the person involved in the gentle interactions caused different reactions. Gentling by the handler resulted in less restless behaviour, compared to gentling by the other two people. The authors concluded that previous positive handling and gentle interactions by the positive handler during stressful procedures, causes a reduction in stress reactions. The person involved in interactions makes a difference in the calming effect on the animals. These results show the importance of positive interactions with animals, as they improve welfare and decrease the risk of dangerous responses by the animals during stressful procedures.

Genotypic Prevalence of the Adhesin Involved in Diffuse Adherence in Escherichia coli Isolates in Pre-weaned Pigs with Diarrhoea in Korea

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The effect of ACTH on pigs' attraction to salt or blood-flavored tail-models.

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As part of the stress response adrenocorticotrophic hormone (ACTH) is released. In other species, an increase in ACTH has been shown to result in an increase in salt appetite. The hypothesis of this study was that stressful situations increase salt appetite and therefore the pig’s attraction to blood. ACTH was injected for five days to mimic a stress response. The chewing behaviour of, and attraction to, salt- or blood-flavored tail models was studied in growing pigs following an injection of ACTH. Sixteen pigs were housed individually during the study. Half of the pigs were treated with ACTH, the other half were not. Tail models were made from sash cord, which was attached to plywood and mounted in each pen. There were three ‘tails’ per mounting: one soaked in pig blood, one soaked in salt solution (both with the same salt concentration) and one soaked in tap water. Attraction to blood does not appear to be due to the salt content in the blood. Regardless of treatment, pigs preferred to chew blood-soaked tail-models. Chewing of salt- and blood-soaked tail-models decreased for the ACTH-injected pigs. Injecting ACTH did not result in an increased salt appetite. Using ACTH to mimic a stress response needs further research. However, based on these results, the underlying cause of tail biting does not appear to be due to a stress induced salt appetite.

Effect of driver behaviour, driving events and road type on the stability and resting behaviour of sheep in transit

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The behavioural responses of sheep to driving events, and the relationship between driver behaviour and driving events were examined, since driving style can have a large impact on the welfare of animals by affecting risk of injury and disturbing their ability to rest. Two drivers drove groups of 10 sheep on a variety of roads, as the driver, the driver’s view of the road, the speedometer, and the sheep were video recorded. Differences in driving style affected the frequency of losses of balance by the sheep slightly, and affected the degree of disturbance to the sheep’s ability to rest during the journey more significantly. Falls were rare, although losses of balance were common. Driving events such as acceleration, braking, stopping, cornering, gear changes, or uneven road surfaces may have caused about 80 % of losses of balance. Only about 22 % of driving events preceded a loss of balance. Driving events may also have been responsible for many interruptions to lying behaviour and rumination. There were fewer losses of balance, more lying down, more rumination and fewer disturbances to the sheep when the driver was travelling on a motorway compared with a single carriageway. The results of this study provide evidence that would promote careful driving as a means of ensuring animal welfare in-transit for future driver training and education. A number of factors influenced by the driver of the vehicle may affect the quality of the journey experienced by sheep during transport.

Do domestic hens discriminate between familiar and unfamiliar conspecifics in the absence of visual cues?

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If allowed to rely on visual, auditory, and olfactory cues from live stimulus birds, domestic fowl are able to discriminate between familiar and unfamiliar conspecifics. However, some wild fowl are forced to rely on non-visual cues to recognize their group mates. In the current study, domestic chickens were tested to see if they could discriminate between familiar and unfamiliar conspecifics in the absence of visual cues. Two preference experiments were conducted. In each test, two live hens (one familiar and one unfamiliar) were presented to the test hen. In experiment one, the test hen was separated by the stimulus hen by only a wire-mesh, allowing the test hen to receive visual, auditory, and olfactory cues from the stimulus hens. In experiment two, visual contact was prevented by using an opaque black cloth as a separator rather than the wire-mesh. The aggregation time with the familiar and unfamiliar bird was recorded as a measure of preference. In experiment one, hens showed significant discrimination between familiar and unfamiliar conspecifics, although their preference for the familiar or unfamiliar bird depended on the experimental series in which they were housed. Hens in experiment two, which had to rely on non-visual cues, did not appear able to discriminate between familiar and unfamiliar hens.

The effect of repeated application of electrical stunning on the welfare of pigs.

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At present approximately 13 million pigs are slaughtered annually in the United Kingdom. Although legislation requires the production of immediate insensibility, implying that a stun can be applied only once, the practice of repeat application of electrical stunning is common. It is not clear whether a repeat application is as effective as the initial stun and if there are any potential welfare problems associated with the practice. This study investigated the effects of repeat applications of electrical stunning (200 V, 50 Hz) following different delays of 15, 60 or 180 s between the initial stun and the repeat applications. Following stunning, the durations of spontaneous physical activity, time to return of reflexes and the duration of the epileptiform activity in the electrocorticogram were examined. The results showed that repeat application of electrical stunning can produce successive epileptic activity and therefore an effective stun. The duration of tonic and clonic phase activity following repeat application was significantly shorter than after a single stun only. There was a tendency for the reflexes to return more quickly following repeat application. The use of electrical stunning to re-stun pigs appears to raise no welfare concerns and although commonly used, should be applied out of necessity rather than as routine practice.

Assessment of mental stress in warmblood horses: heart rate variability in comparison to heart rate and selected behavioural parameters

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Heart rate variability was investigated in order to determine whether it could, in turn, assess alterations of the autonomic nervous system at different levels of excitement. Warmblood horses were given a challenging ground exercise task during which their behavioural and physiological responses could be studied. Prior to commencement of the study, the horses were evaluated at rest and during forward walking, then while made to walk backwards continuously for three minutes, according to a standardised protocol. The horses were then exposed to two training sessions, followed by a re-evaluation of backward walking. Heart rate and heart rate variability parameters, such as the standard deviation of the beat-to-beat intervals, the low (sympathetic tone) and high (parasympathetic tone) frequency component of heart rate variability, and their ratio (index representing the sypatho-vagal balance), were sampled at rest, during forward walking, during the first backward walk, and during the second backward walk. Using video recordings taken during both backward walking sessions, stress-related behaviour was determined. The first backward walk experiment induced a rise in heart rate, low frequency heart rate variability, and the low frequency/high frequency heart rate variability ratio, compared to rest and forward walking. A decrease of high frequency heart rate variability in response to the first backward walking session was noted in comparison to rest and forward walking. The standard deviation of the beat-to-beat intervals decreased from both forward walking and rest, but only the standard deviation of the beat-to-beat intervals at rest was significant. In the second backward walking session, heart rate and the parameters of the sympathetic branch of the autonomic nervous system (low frequency component of heart rate variability, and the index representing the sypatho-vagal balance) were decreased and the vagal tone (high frequency component of heart rate variability) was increased compared to the first backward walking session. According to the duration of stress-indicating behavioural patterns, a decrease of excitement after the two training sessions occurred. At that time backward walking did not differ from forward walking for any parameter measured. It was found that there were correlations between heart rate variability parameters and stress-indicating behaviour, as well as heart rate. The results of this study indicated that the heart rate variability parameters (i.e. both the low frequency and high frequency components) were valuable measures for quantifying sympatho-vagal balance. These measures allow for a more precise assessment of the responses of heart rate and standard deviation of beat-to-beat intervals to mental stress during low intensity exercise.

Assessment of the aversion of hens to different gas atmospheres using an approach-avoidance test.

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High concentrations of CO2 have been used for stunning poultry, but have been considered inhumane because the birds appear to find it aversive. However, Ar or a mixture of Ar and CO2 have been suggested to be more humane. The responses of hens to different gas atmospheres were tested during a series of approach-avoidance tests. Twelve hens were trained in the test apparatus, which consisted of a upper and lower chamber, which were connected by a chute. During the actual testing phase, gas would be injected into the lower chamber. The hens did not have access to feed the night before the training session. During the actual training session, hens were placed in the upper chamber and feed was placed in the lower chamber. The feed was used to motivate the hens to enter the lower chamber. Once the birds were trained to enter the lower chamber, the tests began. During each of six test sessions, a different gas treatment was injected into the lower chamber: air, 30% CO2 -in-air, 45% CO2 -in-air, 60% CO2 -in-air, 70% Ar / 30% CO2, and Ar. All hens were randomly exposed to each treatment. Training continued throughout the experiment, and alternated with the testing days. The results indicated that birds took longer to leave the upper chamber during the training session the day after they have been exposed to 45% CO2 -in-air and Ar. However, there were no differences among the treatments in the latency to leave the upper chamber. There were no differences in the number of stops and retreats when the hens were approaching the lower chamber that was enriched with CO2. The lowest number of stops and retreats were found in the control and Ar treatments. Only one hen was not stunned by the CO2-enriched and Ar-enriched atmospheres. There were no differences in the percentages of hens stunned among the stunning gas treatments. Hens in the 30% CO2 -in-air treatment entered the lower chamber at close to the same frequency as in the Ar treatment. When exposed to 60% CO2 -in-air, most of the hens became stunned in the chute on the way to the lower chamber. Hens that entered the lower chamber before being stunned were intermediate for 45% CO2 -in-air and 70% Ar / 30% CO2. The authors concluded that when stunning/killing chickens, there does not seem to be a welfare problem when using mixtures of up to 60% CO2 -in-air compared to 70% Ar / 30% CO2. Using Ar appears to be slightly more welfare-friendly, but not enough to warrant its use over the other options.

Needle-Free Immunization as Effective as Needle and Syringe Method

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Vaccination of livestock is crucial to developing specific immune resistance to diseases that otherwise cost producers billions of dollars. Vaccination of livestock with needles, intramuscular and subcutaneous, can incur costs through animal stress, vaccine residues, injection site lesions and broken needles. Needle-free injection offers several benefits over traditional means. Vaccine is dispersed as minute particles in skin and other tissue, greatly increasing exposure to white blood cells, and thus improving vaccine uptake. Entry points are minute, minimizing tissue damage at the injection site. The injector can be loaded for multiple injections and needle stick injuries are eliminated. This study, carried out at the University of Saskatchewan.s Vaccine & Infectious Disease Organization (VIDO), evaluated commercial vaccine delivery to piglets using a low-pressure, needle-free jet injector against intra-muscular delivery and found that resulting immunity in needle-free animals was as good or better than that developed by animals immunized using a syringe and needle. Animals immunized with the needle-free jet injector also experienced milder clinical disease. This work confirmed similar results achieved by researchers using other drugs or vaccines. The amount of vaccine remaining on the skin surface post-vaccination with the needle-free method suggested that further studies of needle-free injections could lead to establishment of much smaller effective vaccination doses with this system.

Effects of group size on social behavior following regrouping of growing-finishing pigs.

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Large group size may increase aggression, decrease productivity, and impair animal welfare. The objectives of this study were to assess the effects of group size on social behaviour post-mixing, particularly the distribution of aggression, associated injuries, and resulting productivity. A total of 480 growing-finishing pigs were used in a 12-wk study to quantify the effects of group size (10, 20, 40, and 80 pigs per pen) on aggression, aggression-related injuries, behavioural patterns, and the relationships among aggression, injuries, and growth rate. Pigs were regrouped at 8 weeks of age. Aggression of pigs during the first 8 h post-regrouping was observed by live observation. Injury scores were assessed on individual pigs 48 h after regrouping. Pigs were weighed individually at the beginning and end of the study to determine average daily gain. Total duration of aggression for the 8 h post-regrouping was similar among group sizes and average approximately 14 min per pig. The total number of fights per pig in the groups of 10 pigs was lower than for group of 20, 40, and 80 pigs. When group size was increased to 40 pigs per pen, the average number of naïve fighting pairs (neither pigs had previously fought) increased significantly. However, the ratio of total pigs in the pen to the number of naïve fighting pairs was similar among group sizes. The longest duration of fights and most number of fights occurred in the first 2 h post-regrouping. The proportion of pigs that did not fight during the 8 h post-regrouping was higher in groups of 40 and 80 pigs. Pigs with similar body weights fought for longer time than pigs with large difference in body weight. Total injuries scores, which were positively correlated with aggression, were similar among group sizes. Although initial body weight was positively correlated with the number of fights, the duration of fights and total injury scores, the overall average daily gain was not correlated with aggression and injury scores post-regrouping. In conclusion, pigs in large groups did not evidence a high level of aggression. The commonly held fears of increased aggression, its consequent injuries, and decreased productivity in large groups were not found in this study.