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McGreevy, P. D., Webster, A. J., & Nicol, C. J. (2001). Study of the behaviour, digestive efficiency and gut transit times of crib-biting horses. Vet. Rec., 148(19), 592–596.
Abstract: The spontaneous behaviour and the apparent digestibility of dry matter and fibre and transit times of digesta were compared in four normal horses and four crib-biters. A technique was developed for measuring total gut transit times (TGTT) by using single-stool analysis of the passage of radio-opaque polyethylene markers. Longer TGTT were recorded in the crib-biters than in the normal horses but the orocaecal transit times did not differ. The crib-biters rested less than the normal horses.
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McGreevy, P. D., & Nicol, C. J. (1998). Prevention of crib-biting: a review. Equine Vet J Suppl, (27), 35–38.
Abstract: Crib-biting is a common oral stereotype. Because of perceived deleterious effects on the health and appearance of subjects the prevention of crib-biting is regularly attempted. The resourcefulness of horses in satisfying their motivation to perform this behaviour often frustrates owners' efforts at prevention. This paper reviews the efficacy and observable consequences of attempting to prevent crib-biting by a variety of methods. These include attempts to prevent the grasping of objects, to interfere with air-engulfing and to introduce punishment for grasping and neck-flexion. Other approaches include the use of surgery, acupuncture, pharmaceuticals, operant feeding and environmental enrichment. A remedy that is effective for every crib-biter remains elusive. We conclude that, rather than concentrating on remedial prevention, further research should be directed at establishing why horses crib-bite and how the emergence of crib-biting can be avoided.
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McGreevy, P. D., & Nicol, C. J. (1998). The effect of short-term prevention on the subsequent rate of crib-biting in thoroughbred horses. Equine Vet J Suppl, (27), 30–34.
Abstract: The results of an experimental study of the motivational consequences of short-term prevention of crib-biting are reported here. Eight test horses wore a cribbing collar for 24 h. This was effective in preventing crib-biting in 6 subjects. Using analysis of co-variance that accounted for baseline differences in crib-biting rate, test horses showed significantly more crib-biting than control horses on the first day after prevention (P < 0.05). There was also a highly significant increase in the crib-biting rate of test horses on the first day after prevention in comparison with their baseline rate (P < 0.01). This defines the increase as a post inhibitory rebound. An increase in the novelty of the cribbing bar and an increase in feeding motivation during the period of prevention are rejected as explanations of the rebound in this study. Instead, it is suggested that the rebound reflected a rise in internal motivation to crib-bite during the period of prevention. Behaviours that exhibit this pattern of motivation are generally considered functional; and it has been argued that their prevention may compromise welfare.
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McGreevy, P. D., French, N. P., & Nicol, C. J. (1995). The prevalence of abnormal behaviours in dressage, eventing and endurance horses in relation to stabling. Vet. Rec., 137(2), 36–37.
Abstract: The behaviour of horses competing in different disciplines was studied and the relationship between the time they spent out of the stable and the prevalence of abnormal behaviour was examined. The owners of dressage, eventing and endurance horses were sent a questionnaire and a total of 1101 responses were received, giving data on 1750 horses. The behaviours studied were wood-chewing, weaving, crib-biting/wind-sucking and box-walking. The reported percentage prevalences of abnormal behaviour for the dressage, eventing and endurance horses were 32.5, 30.8 and 19.5, respectively. The relationship between the time spent in the stable and the prevalence of abnormal behaviour was examined by chi 2 tests which showed that there were significant linear trends for the eventing group (P < 0.001) and the dressage group (P < 0.05). It is concluded that the time a horse spends out of the stable is related to the discipline for which it is being trained and in dressage and eventing horses the time spent in a stable is correlated with an increased risk of abnormal behaviour.
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McGreevy, P. D., Richardson, J. D., Nicol, C. J., & Lane, J. G. (1995). Radiographic and endoscopic study of horses performing an oral based stereotypy. Equine Vet J, 27(2), 92–95.
Abstract: There is confusion in the veterinary literature concerning the definition of oral based stereotypies in the horse. This study reports the use of fluoroscopy and endoscopy during cribbiting/wind-sucking in afflicted horses. This permitted observations of movements of the pharyngeal and oesophageal tissues and of the air column within during the stereotypic behaviour. The findings reported show that the sequence of events during crib-biting/wind-sucking is not related to deglutition and that air is not swallowed to the stomach. Transient dilation of the upper oesophagus was recorded and the characteristic noise of wind-sucking coincided with the in-rush of air through the cricopharynx. The oesophageal distension was relieved when the air returned to the pharynx although small quantities passed caudally. It is proposed that the role of contraction of the strap muscles of the neck is to create a pressure gradient in the soft tissues surrounding the oesophagus which provokes movement of air from the pharynx into the oesophagus. The findings suggest that the definitions currently used in the sale of horses are in need of revision.
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McGreevy, P. D., Cripps, P. J., French, N. P., Green, L. E., & Nicol, C. J. (1995). Management factors associated with stereotypic and redirected behaviour in the thoroughbred horse. Equine Vet J, 27(2), 86–91.
Abstract: A greater knowledge of the effect of management factors is required to investigate the ontogeny of abnormal behaviour in the stabled horse. A postal survey of racehorse (flat) trainers yielded information about 22 yard and management factors. The relationship of the factors to the prevalence of abnormal behaviour was analysed by logistic regression. Management factors related to the time spent in the stable showed the strongest associations with stereotypic behaviour. The risk of horses performing abnormal behaviour increased: 1) as the amount of forage fell below 6.8 kg/day, 2) when bedding types other than straw were used, 3) when the total number of horses on the yard was fewer than 75, 4) in association with box designs that minimised contact between neighbouring horses, 5) when hay, rather than other types of forage, was used.
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McGreevy, P. D. Development and Resolution of Behavioural Problems with the. In Havemeier Workshop.
Abstract: The ideals of equestrian technique combine art and science. Therefore students of equitation
encounter measurable variables such as rhythm, tempo and impulsion alongside more ethereal ones such as outline and harmony. This mixture accounts for many of the idiosyncrasies of equestrianism including the subjective scoring of performance in dressage tests, the elusiveness of perfection even at an elite level of competition and the difficulty of expressing equestrian technique in empirical terms (Roberts, 1992). This chapter will describe and offer examples of the unwelcome behavioural responses horses produce under saddle. Two broad sections are then proposed to allow the reader to consider unwelcome behavioural responses caused directly by humans as distinct from those attributable more to the horse than the rider. Ultimately the responsibility for problems in the ridden horse lies with humans since we have undertaken the domestication and exploitation of equids. Therefore it is accepted that the dichotomy is not absolute. The chapter closes with a |
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Clarke, J. V., Nicol, C. J., Jones, R., & McGreevy, P. D. (1996). Effects of observational learning on food selection in horses. Appl. Anim. Behav. Sci., 50(2), 177–184.
Abstract: Fourteen riding horses of mixed age and breed were randomly allocated to observer and control treatments. An additional horse was pre-trained as a demonstrator to walk the 13.8 m length of the test arena and select one of two food buckets using colour and pattern cues. Observer horses were exposed to correct performances of the task by the trained demonstrator, for 20 trials held over 2 days. Control horses were subjected to the same handling and placement procedures as the observer horses but without exposure to the behaviour of the demonstrator. The third day for all subjects was designated as a test day. Each subject was released individually in a predetermined place in the arena, and the latency to walk the length of the test arena to the food buckets, the latency to feed, the identity of the bucket approached and the identity of the bucket selected were recorded on ten consecutive trials. During tests both food buckets contained food to minimize the possibility of individual trial and error learning. On the first trial the mean latency to approach the goal area was 18 s for observer horses, compared with 119 s for control horses (t = 2.8, d.f. = 12, P < 0.01) and the mean latency to eat was 35 s for observer horses, compared with 181 s for control horses (t = 4.86, d.f. = 11, P < 0.001). However, observer horses were no more likely to choose the demonstrated bucket than control horses on the first trial. Twelve of the 14 horses decreased their latency to approach the goal area during the series of ten trials, but there were no significant changes in the buckets selected.
Keywords: Horse; Observational learning; Food discrimination
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McGreevy, P. D., & Rogers, L. J. (2005). Motor and sensory laterality in thoroughbred horses. Appl. Anim. Behav. Sci., 92(4), 337–352.
Abstract: We investigated lateralisation in horses because it is likely to be important in training and athletic performance. Thoroughbred horses (n = 106) were observed every 60 s for 2 h, when they were at pasture, and the position of the forelimbs in relation to one another was recorded. There was a population bias skewed to standing with the left forelimb advanced over the right (i.e. directional lateralisation). Using the first 50 observations, the distribution of preferences was 43 significantly left, 10 significantly right with 53 being non-significant (i.e. ambidextextrous). The strength of motor bias increased with age, suggesting maturation or an influence of training. The horses were also presented with an olfactory stimulus (stallion faeces) to score the tendency to use one nostril rather than the other. A significant preference to use the right nostril first was shown in horses under 4 years of age (n = 61) but not in older horses. Of the 157 horses tested for nostril bias, 76 had been assessed for motor bias and so were used for analysis of the relationship between laterality in the two modalities. There was no significant relationship between direction of foreleg motor bias and first nostril used, total number of inhalations or laterality index of nostril use. The absence of a correlation between laterality of nostril use and motor bias indicates that lateralisation of the equine brain occurs on at least two levels of neural organisation--sensory and motor--a finding that is consistent with other examples of lateralisation in species that have been examined in more detail.
Keywords: Horse; Lateralisation; Training; Olfaction; Forelimb preference
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McGreevy, P. D., & Thomson, P. C. (2006). Differences in motor laterality between breeds of performance horse. Appl. Anim. Behav. Sci., 99(1-2), 183–190.
Abstract: This study examined the relationship between motor laterality in horses bred for different types of work and therefore different temperaments. Foreleg preference during grazing was measured in three populations of domestic horse, Thoroughbreds (TB, bred to race at the gallop), Standardbreds (SB, bred for pacing) and Quarter Horses (QH, in this case bred for so-called “cutting work” which involves manoeuvring individual cattle in and out of herds). With a one-sample t-test, TBs showed strong evidence of a left preference in motor laterality (P = 0.000), as did SBs (P = 0.002) but there was no convincing evidence for laterality in QH (P = 0.117). However, the increasing trend in left preference from QH to SBs then TBs was associated with increasing differences between individual horses within a breed. The overall preference (either left or right) increased with age (P = 0.008) and the rate of increase varied with breeds. The presence of a higher proportion of left-foreleg preferent individuals in TBs and SBs compared with QH may indicate that their training or selection (or both) has an effect on motor bias.
Keywords: Horse; Lateralisation; Laterality; Breed; Training
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