| Home | << 1 2 3 4 5 6 7 8 9 10 >> [11–20] |
|
Ryder, O. A., & Massena, R. (1988). A case of male infanticide in Equus przewalskii. Appl. Anim. Behav. Sci., 21(1-2), 187–190.
Abstract: Following the introduction of a new stallion to a band of E. przewalskii mares two births, both of male foals, resulted in foal death due to injuries sustained in the first day of life. Neither foal was sired by the new herd stallion. The second foal death was the results of an observed attack on the newborn male and is described here. Subsequently births in the same enclosure and, in one instance, to the same mare whose previous foal was killed, were of foals sired by the new stallion and were uneventful, with 3 male foals surviving to date.
|
|
i Rios, J. F., & Houpt, K. (1995). Sexual behavior in geldings. Appl. Anim. Behav. Sci., 46(1-2), 133–135.
Abstract: Abstract
In response to a request published in Equus, a magazine for those interested in horses, 85 owners of older geldings exhibiting sexual behavior completed history forms. The mean age of geldings was 16 f 5 years. Only 39 of the owners had had the gelding for at least a year before the behavior was noted. These cases could be used to determine the true age of onset of the problem. When log survivorship was used to determine whether there were one or two different populations, a break or change in the slope at age 16 indicated that there are two populations. One population shows the behavior from the time of castration and the other first exhibits the behavior in old age, possibly in response to an ACTH secreting pituitary adenoma. A total of 40% of the horses were Quarterhorses, the most numerous breed in the US; 78% of the horses were purebreds. Fewer than half the owners knew the age at which their horse had been castrated because they did not own the horse at the time. The mean age at castration, when known, was 3.3 f 2.5 years. The reason for contacting us was sexual behavior (70%), aggression (24%). or some other problem ( 1 o/o). Whether or not aggression was the presenting problem, most of the horses showed aggression (95%), particularly towards other geldings (88%)) but also towards people (3 1%). Copulatory behavior (mounting) was shown by 69% of the geldings and half of those were able to intromit. These findings indicate that the sexual behavior of geldings is a problem for owners and that aggression usually accompanies sexual behavior. The owners were encouraged to send serum samples taken before and after human chorionic gonadotropin (HCG) administration for testosterone and estrone sulfate analysis to determine whether residual testicular tissue was responsible for the horse’s behavior. Of the 14 horses tested, only one had elevated levels of testosterone indicating that there was residual testicular tissue. A total of six of the owners agreed to treat their horses with cyproheptadine at a dose of 8 mg day- ’ gradually increased to 88 mg day- ’ per horse. A total of three of the horses showed a decline in sexual and aggressive behavior, one got worse and two had side effects and treatment was withdrawn. |
|
Gorecka, A., Golonka, M., Chruszczewski, M., & Jezierski, T. (2007). A note on behaviour and heart rate in horses differing in facial hair whorl. Appl. Anim. Behav. Sci., 105(1-3), 244–248.
Abstract: The relationship between facial hair whorl position and reactivity, as assessed by behavioural measures (handling score = HS; startle reaction to a suddenly appearing novel object = SR; latency to touch a novel object = LNO) and heart rate measures (mean HR; increase in heart rate = IHR) were studied using 55 Konik horses reared either under conventional stable conditions or in the forest reserve. Horses were classified into four groups according to the whorl position and/or shape: (1) high, single whorl above the top eye line, n = 9; (2) medium, single whorl between the top and the bottom eye line, n = 30; (3) low, single whorl below the bottom eye line, n = 10; and (4) elongated or double whorl, n = 6. Horses with a high whorl position demonstrated a lesser degree of manageability as expressed by a lower HS compared to individuals with medium (P = 0.002) or low whorl positions (P = 0.016). Horses with different whorl positions did not differ significantly in their startle response to a suddenly appearing novel object (P = 0.685). The horses with an elongated or double whorl, which appeared only in the forest group, took significantly longer to approach the novel object than horses with medium (P = 0.006) or low (P = 0.005) whorl positions. No significant differences in mean HR and IHR between groups (HR: P = 0.629 and IHR: P = 0.214) were found. In conclusion, this study supports the relationship between the position of the hair whorl on the horses' head and their manageability during handling, as well as the latency to approach an unknown object.
Keywords: Horse; Hair whorls; Behavioural tests; Reactivity; Heart rate
|
|
Croneya, C. C. (2007). Group size and cognitive processes. Appl. Anim. Behav. Sci., 103(3-4), 15–228.
Abstract: Animal group sizes may exert important effects on various cognitive mechanisms. Group
size is believed to exert pressures on fundamental brain structures that correlate with the increased social demands placed on animals living in relatively large, complex and dynamic social organizations. There is strong experimental evidence connecting social complexity, social learning and development of other cognitive abilities in a broad range of wild and domesticated animal species. In particular, group size seems to have significant effects on animals? abilities to derive concrete and abstract relationships. Here, we review the literature pertaining to cognitive processes and behaviours of various animal species relative to group size, with emphasis on social learning. It is suggested that understanding the relationship between group size and cognition in animals may yield practical animal management benefits, such as housing and conservation strategies, and may also have implications for improved animal welfare. Keywords: Group size; Social complexity; Social learning; Cognitive processes
|
|
Minero, M., Zucca, D., & Canali, E. (2006). A note on reaction to novel stimulus and restraint by therapeutic riding horses. Appl. Anim. Behav. Sci., 97(2-4), 335–342.
Abstract: Little research has been done to measure reactivity objectively in therapeutic riding horses (TRH). As individual reactivity and chronic stress could be assessed by exposing animals to acute, novel stressors, the authors of this work aimed at comparing reactions of TRHs and jumping horses (JH) to two challenges. Four TRHs and four JHs were exposed to a restraint covering their head with a hood for 1 h and to a startling stimulus (a 40 cm long, red and white synthetic holiday garland shaken with a rustling noise inside the box). Heart rate (HR) and heart rate variability (HRV) were recorded continuously and telemetrically, the reaction was video-recorded and analysed with a software for behavioural analysis. Blood samples were collected before and after each challenge to determine lymphocyte proliferation and other biochemical parameters. Horses spent most of the time immobile, during the challenges (p < 0.05). TRHs had a significantly higher average basal HR than JH (p < 0.05), probably due to their better condition. HR varied among different behaviours during the restraint (p < 0.05): the average HR during “pawing” was higher than during other behaviours (p < 0.005). A significant decrease in the proliferation of lymphocytes in samples taken after the removal of the hood (p < 0.05) was found, while the other stress related parameters did not vary significantly after the challenges. The authors conclude that TRHs did not react less than JHs to the new stimuli and this should be taken into consideration while planning their daily work and management.
|
|
Krueger, K. (2007). Behaviour of horses in the “round pen technique”. Appl. Anim. Behav. Sci., 104(1-2), 162–170.
Abstract: I investigated the behavioural background of the way horses learn to follow humans in the “round pen technique” suggested by “horse whisperers” as a gentle method for initial horse training. Though the practicability of this technique has been adequately demonstrated in the past, the horses' behaviour during such training has not yet been documented in detail. In a riding arena, horses, that did not follow the trainer immediately, were chased away so that they galloped around the trainer. Galloping horses showed specific behaviour such as turning the ear to the trainer, chewing, licking, and stretching head and throat downwards. In subsequent trials horses needed to be chased for less time and finally followed immediately, even when conditions were changed or the trainer was replaced by another person. This suggests that horses learn to follow in this particular situation and also show some generalisation. However, following did not occur on a pasture even after several successful trials in the riding arena.
Keywords: Learning; Dominance relationship; Horse; Human-animal relationships
|
|
Ninomiya, S., Sato, S., Kusunose, R., Mitumasu, T., & Obara, Y. (2007). A note on a behavioural indicator of satisfaction in stabled horses. Appl. Anim. Behav. Sci., 106(1-3), 184–189.
Abstract: We observed the behaviour of six stabled horses (stallions n = 3; geldings n = 3) in an attempt to identify behavioural measures of eating satisfaction. The horses were required to perform an operant response (pressing a button with the muzzle) in order to access a food reward in an experimental box stall. After each horse had successfully learned the experimental situation, it participated in the experimental protocol on 4 days. Horses were brought to the experimental box stall for the operant response sessions (1 h duration per session), and upon completion, they were returned to their own (home) box stalls. The number of presses for the reward was a Fixed Ratio schedule of either 3 or 12 muzzle presses (FR3, FR12) and the FR procedure for each horse was as follows: FR3 FR12 FR12 FR3 or FR12 FR3 FR3 FR12. Number of rewards obtained during each session, and behaviour and heart rate after each session were recorded for each horse. A repeated measures ANOVA showed that the number of rewards obtained in FR3 was higher than in FR12 (P < 0.05). The horses spent more time in standing-rest, (with ears rotating laterally and exhibiting a low neck position) indicating sleep, in the home box stall, after FR3 compared to FR12 treatments (P < 0.05). Mean heart rate after standing-sleep was significantly lower than mean heart rate in the home box stall (P < 0.01). These results suggest that eating satisfaction induces sleep in stabled horses, and that episodes of standing-sleep behaviour may be a useful indicator of appropriate or enhanced welfare in the horse.
Keywords: Animal welfare; Satisfaction; Horses; Operant response; Stable
|
|
Croney, C. C., Prince-Kelly, N., & Meller, C. L. (2007). A note on social dominance and learning ability in the domestic chicken (Gallus gallus). Appl. Anim. Behav. Sci., 105(1-3), 254–259.
Abstract: Relatively little is known about the relationship between social behavior and specific cognitive abilities of the chicken. It is uncertain whether dominant birds have a cognitive advantage over subordinate birds that might facilitate their superior position in the social hierarchy. Likewise, it is unknown whether subordinate birds compete successfully with higher ranking birds because their cognitive capacities compensate for physical deficits. In this study, the relationship between the chicken's position in the dominance hierarchy and its performance on a cognitive task was explored. Ten pairs of New Hampshire domestic roosters (Gallus gallus) were observed to determine dominance or subordinance within dyads. All birds were then trained and tested on a visual discrimination learning task. Discriminative stimuli were orange and green plastic discs. Correct stimuli (orange or green) were randomly assigned to birds. Placement of the discs (left or right of center) was also randomly assigned and counterbalanced to avoid a side bias. Birds were rewarded with food for pecking at the correct disc. Criterion for task completion was 80% correct responses on three consecutive test sessions or 86% correct on two consecutive sessions. All subjects met the test criterion. The number of trials to criterion was compared between dominant and subordinate birds using a paired t-test. No difference was found in performance between dominant and subordinate birds (p > 0.05) suggesting that in chickens, ability to learn a novel visual discrimination task is not well correlated with rank. Additional studies, particularly using different learning paradigms, are needed to confirm these results.
|
|
Lensink, J., Veissier, I., & Boissy, A. (2006). Enhancement of performances in a learning task in suckler calves after weaning and relocation: Motivational versus cognitive control?: A pilot study. Appl. Anim. Behav. Sci., 100(3-4), 171–181.
Abstract: 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.
Keywords: Calves; Weaning; Learning; Cognition; Behavioural test
|
|
Hansen, M. N., Estvan, J., & Ladewig, J. (2007). A note on resting behaviour in horses kept on pasture: Rolling prior to getting up. Appl. Anim. Behav. Sci., 105(1-3), 265–269.
Abstract: In previous studies on lying behaviour in horses kept in individual boxes we observed that most horses that had been lying down resting sometimes made a rolling behaviour prior to getting up. The rolling behaviour was seen in approximately 30% of the times the horses stood up. To analyse whether the behaviour was caused by individual housing in a box or whether it is a behaviour occurring also under free range conditions, we observed a group of 43 horses kept on pasture throughout the day and night. The horses were observed from 03:00 to 10:00 h over four consecutive mornings, at a time when lying behaviour was frequent. Of the 43 horses observed, the rising procedure was seen in 41 horses, and 25 of these horses (60.9%) performed the rolling behaviour at least once. A total of 135 rising episodes were observed, and 41 followed the performance of a rolling behaviour (30.4%). In contrast to the rolling behaviour seen indoors, the behaviour was more varied outdoors in that some horses rolled anywhere from 45 to 180[degree sign], some even repeatedly, whereas horses in a box only rolled 90[degree sign] and back. In all cases when horses rolled 180[degree sign] they rolled back to the original side before getting up. Also in contrast to previous observations, no horse was observed changing position during the roll. We conclude that the behaviour is a kind of comfort behaviour but that further studies are necessary to explain its function.
|