Recognition of people by dairy calves using colour of clothing.

Posted in: Welfare by admin on January 1, 2003 | No Comments

The objective of this study was to determine whether dairy calves can discriminate among people based on the colour of their clothing. For six days a week, a familiar rewarder, who always wore the same coloured clothing, fed, patted and spoke gently to the calves while they were in their individual pen. The calves were then tested in a Y-maze, and had to make a choice: if they went to the familiar person, they received a milk reward. The calves did not receive anything, when they did not make the correct choice. The calves were tested eight times. Four experiments were conducted. In the first experiment, the familiar rewarder was in one arm of the maze (which was randomized), but the other arm was empty. Eleven of the 14 calves tested successfully completed the test. In the second experiment, a new group of calves were tested to determine if they could successfully discriminate between the familiar rewarder (wearing same clothes as during the familiarization period) and a stranger (wearing different coloured clothes). All calves successfully completed this test. The third experiment tested whether calves could discriminate between the rewarder and non-rewarder when they were both wearing clothes of the same colour. None of the calves were successful during this test. In the fourth experiment, the rewarder and non-rewarder wore clothes of the same colour, but they were a different colour than what was worn during the familiarization period. Only one calf was successful. The results indicate that colour cues are used by young calves to distinguish between people. The Y-maze is a useful method to use when studying the discriminatory abilities of calves.

Differences in Antibiotic Resistance in Escherichia coli, Isolated from East-European Swine Herds With or Without Prophylactic Use of Antibiotics

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Aggression, fearfulness and coping styles in female pigs.

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The coping styles hypothesis in animals has recently received much attention in studies investigating individual differences in personality characteristics partly because of its apparent success in describing the coping strategies used by mice and other species. Pigs, also have large inter-individual variation in behaviour, and show similar reactions to challenging events over time and across related situations. This study evaluates the validity of this hypothesis for predicting the coping responses of pigs by testing for predicted correlations between responses to a variety of challenges. Animals were exposed to an immobility test at 3 weeks of age. At 8 and 24 weeks, animals were exposed to an unknown pig in the test animal’s home cage, a human in the home cage, and a novel object (bucket) in a novel arena. Many of the behavioural measures had some repeatability between the ages of 8 and 24 weeks, despite significant changes in the observed level of responses, but there were few correlations between responses to social and non-social situations. The results indicate that the coping styles hypothesis has very limited value in predicting the coping responses of pigs representing the population as a whole. It is suggested that future research on pig personality should investigate the possibility that specific coping behaviours for example, those mediated by fear and anxiety, may have consequences for different elements of coping ability related to welfare and productivity.

An evaluation of response to novelty as a predictor of pecking tendency in laying hens.

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Selective breeding against feather pecking in laying hens depends on identification of individual birds with the lowest feather pecking activity. If certain behavioural traits are phenotypically and genetically associated with, or predictive of, feather pecking activity then tests for those traits may offer a quicker method of identifying suitable parent birds. In a previous study, pairs of pullets that pecked most frequently at a feather bundle also avoided a novel object in a separate test. In the present study, 319 Brown pullets were tested with a novel object at 7-9 weeks of age to determine whether response to novelty predicted either pecking at feather bundles presented in two different ways (loose or fixed) at both 11-13 and 25-27 weeks of age, or feather pecking in the home pen between 15 and 33 weeks of age. Response to novelty did not predict pecking at feather bundles. There were no associations between the amount of pecking directed towards different types of feather bundle, or between pecking at feather bundles and pecking at the feathers of live birds. Response to novelty also failed to predict tendency to feather peck, although recorded levels of feather pecking, especially severe feather pecking, were relatively low. However, when birds with a varied range of responses to a novel object were housed together, more of the birds feather pecked (P < 0.05), they feather pecked more consistently (P < 0.05) and showed more pecking at the environment in a test than birds with similar responses to novelty.

Milk feeding systems for dairy calves in groups: effects on feed intake, growth and health.

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The rearing of dairy calves in groups is rapidly replacing the once common practice of raising the calves individually. Some farms have chosen to raise the calves in small groups. Group housed calves are fed by bucket or a small container that may or may not have teats. In larger groups (25-30 calves) the easiest way to feed the calves in ad libitum from a container with a teat or from automatic feeders, as computerized feeding systems are becoming quite popular. There are some negative consequences associated with feeding the calves ad libitum. One problem is the decreased growth performance after weaning, as giving the calves ad libitum access to milk tend to decrease the amount of concentrate they eat, thus the conversion from a liquid to solid diet after weaning is much more difficult. Also when feeding the calves ad libitum there is an increase in the cost of feeding due to the higher amounts of milk consumption. Another problem associated with the group housing of calves is the increased chance of contacting an infectious agent, thus promoting infection in these calves. According to a survey of farms, respiratory disease in becoming an increasingly common problem in calves housed in groups, fed from a computerized feeding system. Little research has been conducted on the housing of calves in large groups, so there are many questions that are yet to be answered. Producers are wondering how to prevent larger calves from disturbing the smaller calves in the group when they are at the feeder. Another area in which more research needs to be conducted is at what age and by what method should the calves be introduced to the feeding system. Finally producers want to know how to detect if an animal is ill based on the feed intake records generated from a computerized feeding system. Thus, there is a need for more research to be done in this novel form of dairy calf management.

Individual differences in behaviour and in adrenocortical activity in beef-suckler cows.

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A stable herd of beef-suckler cows was studied to learn more about individual behavioural strategies. Furthermore, these strategies were studied in relation to basic activities, adrenocortical activity, and degree of consistency during social competition. For three months, the social interactions of 19 beef-suckler cows were recorded. The cows were classified as either agonistic dominant (AD), non-agonistic (NA), or agonistic challenging (AC). Lying, standing, feeding and walking (basic activities) and the concentration of faecal cortisol metabolites were compared between groups. Increased social competition was created by reducing the number of feeding places, such that consistency in social strategies could be evaluated. In undisturbed social situations, the most agonistic interactions were initiated by AD animals. Social licking was received the most, and performed the least by AC animals. Agonistic interactions were initiated the least by NA animals, but they performed more social licking than AC animals and the most head play. The dominance values were highest for AD animals, but did not differ between NA and AC animals. The highest frequency of walking, standing, feeding and drinking and the lowest frequency of lying was recorded for AC animals. NA animals had higher concentrations of faecal cortisol metabolites than AC animals. The social competition test confirmed the social strategies that were initially identified. The authors concluded that the identified social strategies were consistent in situations of low and high social competition. The three strategies differed in social behaviour, basic activities, and adrenocorticol activity. The NA and AC animals both have a low ranking status, but use different coping strategies to deal with being subordinate.

The effect of a gradual separation from the mother on later behavioural, immune an dendocrine alterations in artificially reared lambs.

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Lambs were assigned to one of four treatment groups: DS (control dam-suckled), GRAD (gradually separated from their dams to reduced the time spent with the mother over ten days), SUB (abruptly removed from the dam 24 to 30 hours post-partum and provided with a milk substitute), and EM (abruptly removed from the dam 24 to 30 hours post-partum and subjected to a gradual transition from ewe milk to milk substitute over ten days) in order to compare lamb welfare and weight gains. The lambs’ behavioral response to isolation and to an inanimate stimulus (a hobby-horse) was measured at 12 and 32 days of age. Blood samples were collected immediately before, 10 minutes after, and 60 minutes after the isolation test to evaluate cortisol concentrations. The weight gain of the lambs was recorded weekly, and cell-mediated immune response and antibody titers were also determined at set points. The GRAD lambs performed less frequent climbing attempts than the DS lambs when isolated in a novel environment. After introduction of the hobby-horse, GRAD labs took longer to move than the DS, SUB, and EM lambs, and they had quicker movements than the DS lambs. A higher cortisol release was exhibited from the GRAD lambs. They also showed a lower cell-mediated immune response than the other three groups. The GRAD lambs had lower antibody titers than the EM and SUB lambs. A lower growth rate was exhibited among the GRAD lambs than among the other treatment groups. The results of the study indicate that gradual separation of a lamb from its mother negatively affects behavioral, immune, and endocrine responses of artificially reared lambs.

Influence of dietary ß-glucan on growth performance, lymphocyte proliferation, specific immune response and haptoglobin plasma concentrations in pigs

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Immunomodulatory feed additives might offer alternatives to anti-microbial growth
promoters in swine production. The present study was conducted to assess the effects of
b-1,3 ⁄ 1,6 glucans, i.e. of specific yeast cell wall components, on immune function and
growth performance in pigs. After weaning at 4 weeks of age, 75 piglets were allocated to 3
different groups for 4 weeks, the diet was supplemented with 0, 0.015 or 0.03% of
b-glucan, respectively. All animals were vaccinated against porcine reproductive and
respiratory syndrome (PRRS). After 4 weeks, average daily gains (ADG) of b-glucan
treated pigs were not different from the controls. Feed intake was tendentiously (p < 0.1) increased at 0.03% b-glucan, without alteration of feed efficiency. Serum haptoglobin concentrations at the end of the 4 week treatment were increased in all groups when compared to the initial levels (p < 0.001), without differences between the groups (p > 0.05). Haptoglobin levels were inversely related to ADG. Lymphocyte proliferation
indices were not different in control and treatment groups. Specific vaccination responses,
as quantified by the PRRS antibody titres occurred in all animals, but no relation with
b-glucan feeding was observed. Our results indicate marginal benefits of b-glucan
supplements for growth performance and no effect on the immune parameters tested. The
observed trend towards increased feed intake needs further elucidation.

The effects of previous grazing experience and ewe presence on the response to novel grass species by weaned lambs.

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The effects of grazing experience and presence of adult ewes on the response of lambs to introduction of a novel grass species was examined. Lambs had either been artificially reared indoors or were at pasture with their mothers until they were weaned at 3 months of age, at which time five dry, adult ewes joined them. Grazing occurred in sequence, beginning with one, two, three, and then four grass species in four 1-week periods. Grass species were perennial ryegrass, then timothy, then cocksfoot, and finally red fescue. The total time that lambs spent grazing and ruminating increased by grazing experience and somewhat by the presence of the adult ewes. Grazing experience, and to a lesser extent, the presence of adult ewes, also increased the pasture biting rate (number of bites per minute). There was a compounded effect of grazing experience and presence of adult ewes as well. The most preferred species of grass was timothy, followed by perennial ryegrass. The lambs spent the least amount of time grazing red fescue. The time spent grazing cocksfoot and red fescue was increased by grazing experience, but the presence of adult ewes did not increase the time that the lambs spent grazing novel species. The pasture biting rate was higher for grass species that lambs preferred to graze. Neither experience nor presence of adult ewes increased the biting rate on novel species in the period of their introduction. Although both grazing experience and presence of adult ewes increased the total amount of time spent grazing and the pasture biting rate, only grazing experience increased the acceptability of novel species.

Behavioural and physiological responses to an acute stressor in crib-biting and control horses

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It was observed through video-recordings that crib-biting horses perform the stereotypy for 10.4 to 64.7 % of their stabling time. Crib-biting and non-crib-biting horses (controls) were exposed to an arousal-inducing stimulus in order to study the similarities and differences in their response. For the first two days of the experiment, the horses received food from a special bucket. On day three, the food bucket was presented but the horses were not allowed to feed. During and after presentation of the food stimulus, arousal behaviour and crib-biting intensity were studied, as was plasma cortisol concentration, heart rate at rest, and heart rate variability at rest. Heart rate and arousal behaviour in crib-biters and in controls increased in response to the stimulus, but crib-biting frequency decreased. Upon examination of heart rate variability at rest, it was determined that crib-biters had a lower vagral tone (high frequency component) and a higher sympathetic tone (low frequency component) than controls. This lower basal parasympathetic activity may be indicating why crib-biting horses showed neither a significant increase in the high frequency component during presentation of the food stimulus, nor decrease in the high frequency component after presentation of the stimulus, when compared with control horses. Therefore, there may be differences in the tuning of the autonomous nervous system and in the stress reactivity of crib-biting and non-crib-biting horses. The experimental results suggest that crib-biting horses are more stress sensitive than non-crib-biting horses, and they are also physiologically and psychologically less flexible than the non-crib-biting horses.