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Sondergaard, E., & Ladewig, J. (2004). Group housing exerts a positive effect on the behaviour of young horses during training. Appl. Anim. Behav. Sci., 87(1-2), 105–118.
Abstract: In an experiment on the effects of social environment and training on the human-animal relationship, 20 horses were handled according to a defined schedule. Eight horses were housed singly and 12 horses were housed in four groups of 3 horses. Horses were handled three times per week in 10 min sessions from an age of 6 months until 2 years of age during two winter periods. A total of 50 and 70 sessions were given in the first and second period, respectively. Five randomly allocated people performed the training. The training scheme involved leading, tying up, touching, lifting feet, etc. in 43 stages. The horse had to fulfil the performance criteria of each stage in order to get to the next stage. In the first winter period, horses were led to the stable when they had “passed” a stage or after 10 min of training. In the second winter period, horses would start off at stage 1 again, and when they “passed” a stage they went on to the next stage within the same training session. Because of the change in training procedure results were analysed separately for the two winter periods. There was a significant difference between trainers in the number of times they allowed a horse to “pass” a stage within each winter period (χ32, P<0.05; χ32, P<0.001 for the first and the second winter period, respectively). Group housed horses “passed” more stages than single housed horses (17 versus 14; 27 versus 18 in the first and second winter period, respectively; P<0.05 for the interaction). Singly housed horses bit the trainer more frequently than did group housed horses (P<0.01). The responses of group housed horses to training clearly demonstrate the benefits of raising young horses in groups.
Keywords: Horses; Housing; Human-animal relationship; Social environment; Training; Learning
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Spier, S. J., Berger Pusterla, J., Villarroel, A., & Pusterla, N. (2004). Outcome of tactile conditioning of neonates, or “imprint training” on selected handling measures in foals. The Veterinary Journal, 168(3), 252–258.
Abstract: Behavioural reactions to selected handling procedures were compared between conditioned, or imprint-trained, and untrained foals raised on the same farm. Nineteen randomly chosen healthy foals were imprint trained at birth and 24 h later (Group A). Twenty-one similar foals that were not imprint-trained served as age-matched controls (Group B). Training began within 10 min of birth and consisted of touch desensitization by gentle rubbing. Each tactile stimulus was repeated 30-50 times over 45-60 min, until the foal no longer resisted the procedure and appeared relaxed. The procedure was then repeated at 24 h of age. At that time a physical examination and blood analysis were performed to assess the foals' health status. Group B animals were not handled except for a brief physical examination and blood analysis at 24 h of age. Thereafter all foals were kept on pastures with their dams with no further handling until they were three months of age. Any foals handled for other reasons before that time were excluded from the study. At three months, each of the 28 foals that completed the study experienced the following handling procedures: acceptance of restraint, haltering, complete physical examination, acceptance of a plastic rebreathing bag, touching the whole body, intramuscular vaccination in the neck, intranasal vaccination, and deworming with oral paste. Response to each procedure was scored (1=not resistant, 2=low resistance, 3=strong resistance, 4=not possible without major physical restraint). Conditioned foals (Group A) were significantly less resistant to touching the front and hind legs and picking up the hind feet (P<0.05). The administration of vaccines and paste dewormer and the collection of blood were tolerated by the majority of the foals of both groups with no or low resistance. It appeared that neonatal imprint training resulted in a learned behaviour that resulted in decreased self-defence responses towards handling the limbs at three months of age.
Keywords: Early handling; Imprint train; Neonatal foals; Horse
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Squire, L. (2004). Memory systems of the brain: a brief history and current perspective. Neurobiol Learn Mem, 82. |
Staniar, W. B., Kronfeld, D. S., Hoffman, R. M., Wilson, J. A., & Harris, P. A. (2004). Weight prediction from linear measures of growing Thoroughbreds. Equine Vet J, 36(2), 149–154.
Abstract: REASON FOR PERFORMING STUDY: Monitoring weight of foals is a useful management practice to aid in maximising athletic potential while minimising risks associated with deviations from normal growth. OBJECTIVE: To develop predictive equations for weight, based on linear measurements of growing Thoroughbreds (TBs). METHODS: Morphometric equations predicting weight from measurements of the trunk and legs were developed from data of 153 foals. The accuracy, precision and bias of the best fitting equation were compared to published equations using a naive data set of 22 foals. RESULTS: Accuracy and precision were maximised with a broken line relating calculated volumes (V(t + l)) to measured weights. Use of the broken line is a 2 step process. V(t + l) is calculated from linear measures (m) of girth (G), carpus circumference (C), and length of body (B) and left forelimb (F). V(t + I) = ([G2 x B] + 4[C2 x F]) 4pi. If V(t + l) < 0.27 m3, weight is estimated: Weight (kg) = V(t + l) x 1093. If V(t + l) > or = 0.27 m3: Weight (kg) = V(t + l) x 984 + 24. The broken line was more accurate and precise than 3 published equations predicting the weight of young TBs. CONCLUSIONS: Estimation of weight using morphometric equations requires attention to temporal changes in body shape and density; hence, a broken line is needed. Including calculated leg volume in the broken line model is another contributing factor to improvement in predictive capability. POTENTIAL RELEVANCE: The broken line maximises its value to equine professionals through its accuracy, precision and convenience.
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Stull, C. L., Spier, S. J., Aldridge, B. M., Blanchard, M., & Stott, J. L. (2004). Immunological response to long-term transport stress in mature horses and effects of adaptogenic dietary supplementation as an immunomodulator. Equine Veterinary Journal, 36(7), 583–589.
Abstract: Reasons for performing study: Little information exists on the immunological effects of transport or the use of supplements to minimise transport stress. Objectives: To establish baseline ranges and evaluate immunophenotypic and functional changes associated with transport and a nutritional ‘adaptogen’ supplement. Methods: Horses received either supplement (n = 10) or placebos (n = 9) during the 30 day study. After 28 days in stalls, 12 horses (6 supplement; 6 placebo) were transported for 24 h, then unloaded and recovered. Venous blood samples were collected on Days 1, 14 and 28 to establish baselines, and on Days 28, 29 and 30 to examine changes during transport and recovery. Results: Transport prompted elevations (P<0.05) in cortisol concentration, neutrophil count and white blood cell counts, while lymphocyte subpopulation counts (CD3+, CD4+, CD8+, CD21+) decreased (P<0.05). Normal phenotypic lymphocyte profiles returned within 24 h of recovery. Supplement effects on immunophenotype (CD21+ and CD8+) were observed in stabled horses (P<0.05), but not in transported horses. Conclusions: These results provide insights into the immunological mechanisms associated with long-term transport. Potential relevance: The existence of a small window of immunological uncertainty follows long-term transportation, enhancing the potential risk of infectious disease in susceptible individuals.
Keywords: horse; transportation; Cd+; lymphocytes; stress; cortisol; adaptogens
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Subiaul, F., Cantlon, J. F., Holloway, R. L., & Terrace, H. S. (2004). Cognitive imitation in rhesus macaques. Science, 305(5682), 407–410.
Abstract: Experiments on imitation typically evaluate a student's ability to copy some feature of an expert's motor behavior. Here, we describe a type of observational learning in which a student copies a cognitive rule rather than a specific motor action. Two rhesus macaques were trained to respond, in a prescribed order, to different sets of photographs that were displayed on a touch-sensitive monitor. Because the position of the photographs varied randomly from trial to trial, sequences could not be learned by motor imitation. Both monkeys learned new sequences more rapidly after observing an expert execute those sequences than when they had to learn new sequences entirely by trial and error.
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Sullivan, R. M. (2004). Hemispheric Asymmetry in Stress Processing in Rat Prefrontal Cortex and the Role of Mesocortical Dopamine. Stress, 7(2), 131–143.
Abstract: The prefrontal cortex (PFC) is known to play an important role not only in the regulation of emotion,
but in the integration of affective states with appropriate modulation of autonomic and neuroendocrine stress regulatory systems. The present review highlights findings in the rat which helps to elucidate the complex nature of prefrontal involvement in emotion and stress regulation. The medial PFC is particularly important in this regard and while dorsomedial regions appear to play a suppressive role in such regulation, the ventromedial (particularly infralimbic) region appears to activate behavioral, neuroendocrine and sympathetic autonomic systems in response to stressful situations. This may be especially true of spontaneous stress-related behavior or physiological responses to relatively acute stressors. The role of the medial PFC is somewhat more complex in conditions involving learned adjustments to stressful situations, such as the extinction of conditioned fear responses, but it is clear that the medial PFC is important in incorporating stressful experience for future adaptive behavior. It is also suggested that mesocortical dopamine plays an important adaptive role in this region by preventing excessive behavioral and physiological stress reactivity. The rat brain shows substantial hemispheric specialization in many respects, and while the right PFC is normally dominant in the activation of stress-related systems, the left may play a role in countering this activation through processes of interhemispheric inhibition. This proposed basic template for the lateralization of stress regulatory systems is suggested to be associated with efficient stress and emotional self-regulation, and also to be shaped by both early postnatal experience and gender differences. |
Thompson, R. N., Robertson, B. K., Napier, A., & Wekesa, K. S. (2004). Sex-specific Responses to Urinary Chemicals by the Mouse Vomeronasal Organ. Chem. Senses, 29(9), 749–754.
Abstract: Social behaviors of most mammals are affected by chemical signals, pheromones, exchanged between conspecifics. Previous experiments have shown that behavioral responses to the same pheromone differ depending on the sex and endocrine status of the respondent. Although the exact mechanism of this dimorphism is not known, one possible contributor may be due to sexually dimorphic receptors or due to differences in central processing within the brain. In order to investigate the differences in response between male and female mice to the same pheromonal stimulus two urinary compounds (2-heptanone and 2,5-dimethylpyrazine) were used to stimulate the production of Inositol (1,4,5)-trisphosphate (IP3) in microvillar membrane preparations of the vomeronasal organ as an indirect measurement of pheromonal stimulation. Incubation of such membranes from prepubertal mice with urine from the same sex or opposite sex, results in an increase in production of IP3. This stimulation is mimicked by GTP{gamma}S and blocked by GDP{beta}S. Furthermore we found that 2-heptanone present in both male and female urine was capable of stimulating increased production of IP3 in the female VNO but not the male VNO. Finally, 2,5-dimethylpyrazine present only in female urine was also only capable of stimulating increased production of IP3 in the female VNO.
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Tomasello, M., & Call, J. (2004). The role of humans in the cognitive development of apes revisited. Anim. Cogn., 7(4), 213–215. |
Tommasi, L., & Polli, C. (2004). Representation of two geometric features of the environment in the domestic chick ( Gallus gallus). Anim. Cogn., 7(1), 53–59.
Abstract: We report experiments based on a novel test in domestic chicks ( Gallus gallus), designed to examine the encoding of two different geometric features of an enclosed environment: relative lengths of the walls and amplitude of the corners. Chicks were trained to search for a food reward located in one corner of a parallelogram-shaped enclosure. Between trials, chicks were passively disoriented and the enclosure was rotated, making reorientation possible only on the basis of the internal spatial structure of the enclosure. In order to reorient, chicks could rely on two sources of information: the relative lengths of the walls of the enclosure (associated to their left-right sense order) and the angles subtended by walls at corners. Chicks learned the task choosing equally often the reinforced corner and its rotational equivalent. Results of tests carried out in novel enclosures, the shapes of which were chosen ad hoc (1) to induce reorientation based only on the ratio of walls lengths plus sense (rectangular enclosure), or (2) to induce reorientation based only on corner angles (rhombus-shaped enclosure), suggested that chicks encoded both features of the environment. In a third test, in which chicks faced a conflict between these geometric features (mirror parallelogram-shaped enclosure), reorientation seemed to depend on the salience of corner angles. These results shed light on the elements of the environmental geometry which control spatial reorientation, and broaden the knowledge on the geometric representation of space in animals.
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