Role of diet and feeding in normal and stereotypic behaviors in horses

Effect of pony morphology and hay feeding methods on back and neck postures

The application of hay feeding devices, such as the use of hay nets or slow feeders, can help with the management of weight in ponies; however, there is still a lack of knowledge regarding their effect on equine posture. Therefore, the aim of the study was to assess the effect of different feeding devices on the posture of ponies using morphometric analysis. Two different breed types, Shetland type (SH, n = 5) versus Welsh Cob type (WC, n = 4), were fed the same forage in four different ways: on the ground (G), using a fully filled haynet (HF), using a partially filled haynet (HL) and using a slow-feeder hay box (HB). Video recordings were obtained and then geometric morphometric analysis was applied. Breed morphology was confirmed by body morphometric measurements. Data were analysed statistically using one-way ANOVA, canonical variate analysis (CVA), principal component analysis (PCA), partial least-squares (PLS) analysis and multivariate analysis of variance (MANOVA). Moreover, a mixed model was performed to study differences in mandibular angle. SH and WC ponies were shown to have significantly different body morphometric measurements. The geometric morphometric analysis results showed that ponies arch their back and modify their neck shape differently according to the feeding method and their morphological group. For the neck, the SH and WC ponies adapted similarly to the use of small-holed hay nets, but their posture varied when feeding from the ground or hay box. The back postures consistently differed according to the breed type and feeding method. The mandibular angle for both breed types was reduced with all the feeding devices compared to feeding from the ground. Further studies are needed to evaluate the long-term effects of slow-feeding devices on posture and mandibular angle, taking into consideration animals with different morphologies.

Effects of soaked hay on lung function and airway inflammation in horses with severe asthma

BACKGROUND

Reducing inhaled dust particles improves lung function in horses with severe asthma. Soaked hay is commonly used by owners, but its efficacy in improving lung function and inflammation has not been documented.

OBJECTIVES

To measure the effects of soaked hay and alfalfa pellets in horses with severe asthma.

ANIMALS

Ten adult horses with severe asthma from a research colony.

METHODS

Prospective controlled trial. Horses in clinical exacerbation were housed indoors and allocated to be fed either soaked hay (n = 5) or alfalfa pellets (n = 5) for 6 weeks. Soaked hay was immersed for 45 minutes and dried out hay was discarded between meals. Pulmonary function and clinical scores were measured before and after 2, 4, and 6 weeks. Tracheal mucus scores and bronchoalveolar lavages were performed before and after 6 weeks. Lung function was analyzed with a linear mixed model using log-transformed data.

RESULTS

Lung resistance decreased from (median (range)) 2.47 (1.54-3.95) to 1.59 (0.52-2.10) cmH2 O/L/s in the pellets group and from 1.89 (1.2-3.54) to 0.61 (0.42-2.08) cmH2 O/L/s in the soaked hay group over the 6-week period for an average difference of 1.06 cmH2 O/L/s for pellets (95% confidence interval [95% CI]: 0.09-2.04, P = .03, not significant after correction) and 1.31 cmH2 O/L/s for soaked hay (95% CI: -0.23 to 2.85, P < .001, significant).

CONCLUSION AND CLINICAL IMPORTANCE

Soaked hay can control airway obstruction in horses with severe asthma. The strict protocol for soaking and discarding dried-out hay in this study could however be considered too great of an inconvenience by owners.

Does Feeding Management Make a Difference to Behavioural Activities and Welfare of Horses Reared for Meat Production?

Horses reared for meat production are generally fed a diet rich in starch with the aim of maximizing production performances. This study evaluated the effects of two feeding management systems on horse welfare by analysing the relative time spent engaged in different behavioural activities. Nineteen Bardigiano horses aged 14.3 ± 0.7 months were randomly assigned to one of two group pens: one group was fed high amounts of starch-rich concentrates (HCG; n = 10), the other was fed a fibre-based diet (HFG; n = 9). Behavioural activities performed by each horse were video-recorded over a 96-h period. A scan sampling process (n = 144 scans/horse/day; total n of scans sampled = 10,368) was used, and the scans were analysed according to a specific ethogram. The mean frequency (%/24 h) spent exhibiting each behavioural activity was calculated to obtain the time budget. After checking for normality (Shapiro–Wilk test), Student’s t tests (normally distributed data) and Mann–Whitney tests (not normally distributed data) were used to compare the time budgets of the two groups of horses (HCG vs. HFG). Principal Component Analysis (PCA) was applied to identify the components explaining the variability in behavioural activities between the two groups. K-means cluster analysis subsequently confirmed the PCA results. The behavioural activities associated with feeding horses a fibre-based diet correlated with better horse welfare compared with feeding horses a starch-based diet. Feeding horses a fibre-based diet resulted advantageous from both the welfare and economic perspective; it allowed horses to spend more time expressing feeding behaviours and reduced energy expenditure in the form of excitable, or “fizzy”, behaviours.

A high-starch vs. high-fibre diet: effects on the gut environment of the different intestinal compartments of the horse digestive tract

Background

Horses are often fed high amounts of starch in their diets despite the well-established benefits of a fibre-based diet to promote gut health and animal welfare. The aim of the present study was to compare the effects of two different diets – one based on high amounts of starch (HS) vs. one base on high amounts of fibre (HF) – on specific parameters of the gut environment across different intestinal compartments of the horse digestive tract. To this end differences in the gastrointestinal environment between HS vs. HF fed horses were assessed in terms of dry matter, organic matter and ash content; the particle size distribution and volatile fatty acid composition were also investigated.

Results

Nineteen Bardigiano horses of 14.3 ± 0.7 months of age and destined to slaughter were divided into two group pens – one fed with high amounts of starch (HS; n = 9; 43% hay plus 57% starch-rich pelleted feed); vs. fed with high amounts of fibre (HF; n = 10; 70% hay plus 30% fibre-rich pelleted feed). Horses fed HS diet presented a higher dry matter content in the right dorsal colon. Moreover, they showed a higher organic matter and ash content in the sternal flexure, pelvic flexure, right dorsal colon and rectum. In these latter intestinal compartments, horses fed a HS diet also showed a higher proportion of particles retained on an 8 mm sieve and a higher proportion of particles that washed through the finest sieve (< 1 mm). Moreover, the total amounts of volatile fatty acids as well as valeric acid were found to be significantly higher in horses fed the HS vs. HF diet.

Conclusions

A high-starch diet causes significant changes in the horse gut environment. We observed an increase in the dry matter content in the right dorsal colon, as well as reduced particle sizes and an increase in the production of valeric acid in all the gut compartments studied. High-starch diets should be avoided in favour of fibre-based diets with the goal of safeguarding gut health in horses.

Colombian Creole Horse: Frequency of oral and motor stereotypies

Background and Aim: The current stable housing of Colombian Creole Horses severely restricts the animals' locomotion and natural behaviors. In addition, their feed consists of a combination of high-energy concentrates with considerably little forage which potentially leads to locomotor or oral stereotypies. This study aimed to report the frequency of locomotor and oral stereotypies in Colombian Creole Horses in Girardota (Antioquia, Colombia) and associated risk factors. Materials and Methods: A prospective cross-sectional study was conducted from 2019 to 2020, in which 102 stabled horses aged 28 months and older participated. A questionnaire was developed to collect information on the horses' daily barn routines. The horses were observed twice a day for 2 h for 3 consecutive days to record information related to stereotypy behaviors. The Fisher's exact test and the Mann–Whitney U test were utilized for data analyses. Associations were considered statistically significant at p<0.05. Results: Among the horses evaluated, 32.35% presented at least one stereotyped behavior. The most common was crib-biting (i.e., cribbing), with 17.65% exhibiting this behavior. Age, weight, gender, type of feeding, visual contact between horses, and natural lighting were all associated with oral stereotypies. Crib-biting was most common in young horses (U=1.36, p≤0.05), wind-sucking was more common in lighter weight animals (U=1.45, p=0.01), and lip-smacking was more common in stallions (χ2=9.10, p≤0.01). It is noteworthy that their feeding diet included bran, molasses, and gopher. Horses that did not have visual contact with other horses and those that did not have natural lighting were associated with pica (χ2=9.52, p≤0.02; χ2=3.72, p≤0.05; and χ2=3.72, p≤0.05, respectively). Of locomotor stereotypies, kicking the wall was significant in young animals (U=1.54, p=0.03) and walking in circles in lactating mares (χ2=13.20, p≤0.02). Conclusion: Housing conditions in this study were found to have several risk factors affecting horses that exhibit stereotypic behaviors, and all these factors resulted in a higher frequency of stereotypies. Establishing risk factors for the presentation of abnormal behaviors allows for the implementation of better management practices in the production systems of the Creole Colombian Horse and will help improve their overall welfare.

Factors Associated With the Development and Prevalence of Abnormal Behaviors in Horses: Systematic Review With Meta-Analysis

Researchers believe that the development and prevalence of abnormal behaviors in horses may be caused by several environmental and biological factors, and the literature offers numerous reports that discuss the causes and effects of stereotypies in these animals. In this light, this study aimed to conduct a systematic review and meta-analysis of the scientific literature, summarizing the main risk factors associated with the development of abnormal behaviors in horses. The searches were conducted over the course of four years in Portuguese, Spanish, and English. The publications reviewed were full text research thesis or articles that addressed issues within the following criteria: (1) presentation of epidemiological information on the studied population; (2) prevalence of abnormal behaviors in equine populations; (3) factors associated with the development or prevalence of stereotypies. Data were extracted from each study and inserted into an Excel spreadsheet to be analyzed through descriptive statistics. In addition, the Mann-Whitney U test was used to verify the existence of significant differences between the methodologies (direct observation/questionnaires). The dataset was also analyzed through data mining to identify the main factors that influence the prevalence of abnormal behaviors in the studied population. The results showed a great variation in the mean prevalence of abnormal behaviors, with no significant difference between research conducted through questionnaires or direct observation, and the data mining technique identified that incorrect nutritional management may be the main factor influencing the development and prevalence of abnormal behaviors in horses.

A Fibre- vs. cereal grain-based diet: Which is better for horse welfare? Effects on intestinal permeability, muscle characteristics and oxidative status in horses reared for meat production

Horses reared for meat production are fed high amounts of cereal grains in comparison with horses raised for other purposes. Such feeding practice may lead to risk of poor welfare consequences. The aim of this study was to investigate the effects of two feeding practices on selected metabolic parameters and production aspects. Nineteen Bardigiano horses, 14.3 ± 0.7 months of age, were randomly assigned to two groups-one fed with high amounts of cereal grains (HCG; n = 9; 43% hay plus 57% cereal grain-based pelleted feed) vs. one fed with high amounts of fibre (HFG; n = 10; 70% hay plus 30% pelleted fibrous feed)-for 129 days. At slaught on abattoir, biological and tissue samples were collected to evaluate the microbiological contamination of mesenteric lymph nodes and liver; selected meat quality traits (chemical composition and fatty acid profile of the Longissimus thoracis et lumborum muscle); and the oxidative status of the horse. A linear mixed model was used: dietary treatment and sex were fixed effects and their interaction analysed on production and metabolic parameters as dependent variables. Results showed an increased intestinal permeability in the horses fed HCG compared to HFG, according to the significant increased total mesophilic aerobic bacteria counts in mesenteric lymph nodes (p = 0.04) and liver samples (p = 0.05). Horses in HCG showed increased muscle pH (p = 0.02), lighter muscle colour (L) (p = 0.01), increased intramuscular fat concentrations (p = 0.03), increased muscle glutathione peroxidase and superoxide dismutase activities (p = 0.01 and p = 0.03, respectively). Moreover, horses in HCG had lower muscle water holding capacity at interaction with sex (p = 0.03, lower in female), lower muscle protein content (p = 0.01), lower concentration of muscle PUFAs (p = 0.05) and lower plasma catalase activities (p = 0.05). Our results showed that feeding a high cereal grains diet can have global effects on horse physiology, and thus represents a threat for their welfare.

Bidirectional Behavioral Selection in Mice: A Novel Pre-clinical Approach to Examining Compulsivity

Obsessive-compulsive disorder (OCD) and related disorders (OCRD) is one of the most prevalent neuropsychiatric disorders with no definitive etiology. The pathophysiological attributes of OCD are driven by a multitude of factors that involve polygenic mechanisms, gender, neurochemistry, physiological status, environmental exposures and complex interactions among these factors. Such complex intertwining of contributing factors imparts clinical heterogeneity to the disorder making it challenging for therapeutic intervention. Mouse strains selected for excessive levels of nest- building behavior exhibit a spontaneous, stable and predictable compulsive-like behavioral phenotype. These compulsive-like mice exhibit heterogeneity in expression of compulsive-like and other adjunct behaviors that might serve as a valuable animal equivalent for examining the interactions of genetics, sex and environmental factors in influencing the pathophysiology of OCD. The current review summarizes the existing findings on the compulsive-like mice that bolster their face, construct and predictive validity for studying various dimensions of compulsive and associated behaviors often reported in clinical OCD and OCRD.

Activity Time Budgets-A Potential Tool to Monitor Equine Welfare?

Simple Summary

Horses’ behavior is a good indicator of their welfare status. However, its complexity requires objective, quantifiable, and unambiguous evidence-based assessment criteria. As healthy, stress-free horses exhibit a highly repetitive daily routine, horses’ time budget (amount of time in a 24 h period spent on specific activities) can assist in equine welfare assessment. A systematic review of the literature yielded 12 papers that assessed equine time budgets for eating, resting and movement for a minimum of 24 continuous hours. A total of 144 horses (1–27 years old), 59 semi-feral and 85 domesticated horses, are included in this review. The reported 24 h time budgets for eating ranged from 10% to 66.6%, for resting from 8.1% to 66%, for lying from 2.7% to 27.3%, and for movement from 0.015% to 19.1%. The large variance in time budgets between studies can largely be attributed to differences in age and environmental conditions. Management interventions (free access to food, increased space, decreased population density) in domesticated horses yielded time budgets similar to semi-feral horses. The data support the importance of environmental conditions for horses’ well-being and the ability of time budgets to assist in monitoring horses’ welfare.

Abstract

Horses’ behavior can provide valuable insight into their subjective state and is thus a good indicator of welfare. However, its complexity requires objective, quantifiable, and unambiguous evidence-based assessment criteria. As healthy, stress-free horses exhibit a highly repetitive daily routine, temporal quantification of their behavioral activities (time budget analysis) can assist in equine welfare assessment. Therefore, the present systematic review aimed to provide an up-to-date analysis of equine time budget studies. A review of the literature yielded 12 papers that fulfilled the inclusion criteria: assessment of equine time budgets for eating, resting and movement for a minimum of 24 continuous hours. A total of 144 horses (1–27 years old), 59 semi-feral and 85 domesticated horses, are included in this review. The 24 h time budgets for foraging or eating (10–6.6%), resting (8.1–66%), lying (2.7–27.3%), and locomotion (0.015–19.1%) showed large variance between studies, which can largely be attributed to differences in age and environmental conditions. Management interventions in domesticated horses (ad libitum access to food, increased space, decreased population density) resulted in time budgets similar to their (semi-)feral conspecifics, emphasizing the importance of environmental conditions and the ability of time budgets to assist in monitoring horses’ welfare.

The Influence of Stable Management and Feeding Practices on the Abnormal Behaviors Among Stabled Horses in Malaysia

The present study aimed to provide preliminary data on the prevalence of oral stereotypic, locomotory stereotypic, and redirected behaviors as well as their associations with stable management and feeding practices. In this cross-sectional study, a total of 207 working horses used for leisure riding, equestrian sport, polo, endurance, and patrolling were selected from seven equine facilities. Data on the stable management and feeding practices were obtained through the stable records, interviews, and on-site monitoring visits, whereas the prevalence of abnormal behaviors in the studied population was determined using the instantaneous scan sampling method. Most horses in the present study worked for more than 8 hours per week (n = 93). In addition, more horses were fed three times per day (n = 65) with different amounts of hay, concentrate, and chaff. Among the study population, oral stereotypic behaviors had the highest prevalence (n = 281; 54%), followed by redirected behavior (n = 181; 34%), and locomotory stereotypic behaviors had the lowest prevalence (n = 63; 12%). The oral stereotypic behavior was found to be significantly influenced (P < .05) by the working hours, amount of hay, and amount of concentrate. Both locomotory stereotypic and redirected behaviors were found to be influenced (P < .05) by the number of feedings per day and the amount of hay. In summary, the present study has proven that the stable management and feeding practices could influence the prevalence of different abnormal behaviors in the majority of working horses, with oral stereotypy being the most common abnormal behavior in this country.

Welfare of Free-Roaming Horses: 70 Years of Experience with Konik Polski Breeding in Poland

To prevent abuse and to assure the welfare of domestic horses, attempts to assess welfare in a standardized way have been made. Welfare-assessment tools often refer to the physical and social environments of feral domestic horses as examples of welfare-friendly conditions for horses. However, free-roaming horses are often exposed to conditions or states that may be regarded as welfare threats or abuse. The aim of this review was to present cases of welfare compromises as well as natural ways to restore high standards of welfare to Konik polski horses (Koniks) living in semiferal conditions in a forest sanctuary over the course of 70 years. Welfare problems in Koniks related to feeding, locomotor, social, reproductive, and comfort behavior, as well as health issues concerning hoof trimming and parasitism in Koniks, are discussed. Periodic food scarcity or abundance, stressful events around weaning and gathering, the consequences of fights among stallions, exposure to sire aggression during dispersal, lameness during "self-trimming," exposure to insect harassment, high levels of parasitism, and specific landscape formations may endanger free-roaming horses. It has to be underlined that despite the excellent adaptability of horses to free-roaming conditions, one should be aware that welfare problems are to be expected in any semiferal population. Here, we present the management system applied for 70 years in free-roaming Konik polski horses that minimizes welfare threats. It allows close follow-up of individual horses, the strict monitoring of health and welfare on a daily basis, and if necessary, instant reactions from caretakers in cases of emergency. Moreover, it addresses the problem of starvation due to overgrazing and thus, the ethical controversy related to the eradication of surplus animals causing environmental damage.

Inducing weight loss in native ponies: is straw a viable alternative to hay?

BACKGROUND

Obesity is a growing problem in UK equine population. Achieving weight loss in obese horses and ponies at risk of laminitis is an important but often challenging objective.

METHODS

We hypothesised that supplementing poor winter pasture with a mix of barley straw and hay (50:50) rather than hay alone (group B) would lead to weight loss in grazing equids over winter. For this purpose, a group of 40 horses were fed either the straw mix (group A) or hay alone (group B) over winter.

RESULTS

Over the study period, all animals in group A (n=25) lost weight with a mean weight change of -27±17 kg, while in group B (n=15) only 3 out of 15 lost weight (20 per cent), and overall, group B gained weight (+6±18 kg).

CONCLUSIONS

This study suggests that straw is a cost-effective and low-energy roughage, which may be a useful alternative to hay alone when trying to induce weight loss in grazing equids over winter. There were no episodes of colic or laminitis during the study period in either group.

Determinants of Undesirable Behaviors in American Quarter Horses Housed in Box Stalls

The objective of this study was to investigate the management practices that affect undesirable behaviors in American Quarter Horses (AQH) confined to box stalls. A total of 105 adult AQH, comprising 29 females, 22 intact males, and 54 castrated males, housed in box stalls for at least 30 days, were included in the study. Behavioral activities were recorded through visual inspection at 5-min intervals over a 24-h period by two observers who took turns in shifts of 4 hours. Parameters related to animal characteristics, stall conditions, handling, training, nutrients supplied, and feeding behaviors were considered independent variables, and the time spent in undesirable behaviors was the dependent variable. Data were subjected to exploratory factor analysis and hierarchical cluster analysis. Four principal components were extracted. Two clusters were identified based on the time spent in undesirable behaviors: low-incidence group (25 ± 13 minutes) and high-incidence group (97 ± 52 minutes). Nutritional status (P = .1447), physiological status (P = .1372), and training routine (P = .1160) had no significant effects on the dependent variable; however, the effect of feeding behavior (P = .0444) was significant. A low dry matter intake/requirement ratio (P = .0470) and a high heart rate at rest (P = .0444) indicated that inadequate nutrient supply is a determinant of the time spent in undesirable behaviors in AQH. Aspects related to management practices such as horse nutrition, feeding behaviors, and training routine should be considered to reduce undesirable behaviors in AQH.

Personality, abnormal behaviour, and health: An evaluation of the welfare of police horses

An animal's welfare depends on an individual's capacity to adapt to the environment in which it lives. This adaptation is directly associated with the quality of the environment and to the possibility of expressing natural behaviours. Horses kept in stables often display a range of abnormal behaviours related to lack of control over their environment, which can lead to behavioural and health problems. An individual's personality also plays an important role in its susceptibility and resilience to the development of diseases and abnormal behaviour; thus, an evaluation of horses' personalities could be crucial to selecting individuals best able to cope with different work activities. This study aimed to assess the well-being of police horses maintained in a semi-confinement regime in Brazil by associating their personalities to the occurrence of abnormal behaviours and disease. Using a non-invasive approach, different tests were performed to investigate the horses' behaviour, personality and welfare. A frustration test and a novel object test were conducted with 46 horses and the individuals' personalities were assessed using questionnaires and behaviour tests. In addition, we evaluated their physical health through a survey of their veterinary records. The data for horses were evaluated individually. The results demonstrated the occurrence of multiple abnormal behaviours motivated by factors such as diet and lack of social contact. Moreover, the personality tests indicated this is an important component when evaluating welfare, since correlations were found between personality traits and abnormal behaviour expression, and between personality traits and health problems. According to our results, passive, stubborn, and confident horses are better suited to be selected as police horses. The ability to classify horses according to their personalities could help in selecting horses most suitable for patrolling, thereby helping to reduce behavioural problems and increasing animal well-being.

Equine Calming Products: A Short Survey Into Their Use, Effect, and Knowledge Using a Small Sample of Horse Owners in the North of Scotland, UK

Equine calming products (ECPs) are often used by horse owners to alter or mitigate unwanted or dangerous behaviors in various situations. Little scientific research to date examines horse owners' knowledge surrounding these products. The objective of this pilot survey was to determine horse owners' use and perceptions of ECPs. For convenience, a survey was distributed to riding club members, livery yards, and riding instructors in the North of Scotland, UK, to ascertain the following information; the number of horse owners and caretakers who use an ECP, whether the product was considered to be effective, reasons for use and identification of the effective ingredient. Total response rate was 63% (n = 58); correctly completed questionnaires were received. Of the total respondents, 69% (n = 40) confirmed the use of an ECP and 82% would use them again, and 45% reporting regular use. Over half (59%) thought the calming effect was induced by magnesium, 9% thought the calming effect was induced by herbs, valerian, or tryptophan, and 32% did not know what ingredient had a possible calming effect. Of those using or having used an ECP, 40% felt that there was some positive effect, 30% were unsure as to whether there was any difference or not, 25% felt there was no difference, and 5% felt there was a negative effect on horse's behavior. A variety of reasons were given for using an ECP. The results suggest that horse owners are willing to use ECPs without underpinning knowledge of ingredients or scientific evidence of efficacy.

Efficacy of a Feed Dispenser for Horses in Decreasing Cribbing Behaviour

Cribbing is an oral stereotypy, tends to develop in captive animals as a means to cope with stress, and may be indicative of reduced welfare. Highly energetic diets ingested in a short time are one of the most relevant risk factors for the development of cribbing. The aim of this study was to verify whether feeding cribbing horses through a dispenser that delivers small quantities of concentrate when activated by the animal decreases cribbing behaviour, modifies feeding behaviour, or induces frustration. Ten horses (mean age 14 y), balanced for sex, breed, and size (mean height 162 cm), were divided into two groups of 5 horses each: Cribbing and Control. Animals were trained to use the dispenser and videorecorded continuously for 15 consecutive days from 1 h prior to feeding to 2 h after feeding in order to measure their behaviours. The feed dispenser, Quaryka®, induced an increase in time necessary to finish the ration in both groups of horses (P < 0.05). With Quaryka, cribbers showed a significant reduction of time spent cribbing (P < 0.05). After removal of the feed dispenser (Post-Quaryka), cribbing behaviour significantly increased. The use of Quaryka may be particularly beneficial in horses fed high-energy diets and ingesting the food too quickly.

Rapid animal welfare assessment: an archaeological approach

The welfare of an individual depends on its capacity to overcome suboptimal conditions in its environment; otherwise, its physical and psychological health becomes compromised. A situation that clearly indicates lack of control of the environment is the expression of abnormal behaviours, such as stereotypies. This study aimed to verify the well-being of police horses using a new rapid form of welfare assessment: an archaeological approach. To this end, we sampled and quantified marks found on the stables, deposited as a result of abnormal behaviour. We cross-referenced these physical marks with veterinary records of diseases, such as colic, known to be associated with stress. A total of 46 horses were sampled and the results showed a significant medium-strength, positive correlation between bite mark frequency on stable doors and the incidence of colic. A weak significant positive correlation was found between length of scratch marks (from pawing) and the incidence of lameness. We conclude that these marks reflect the accumulated expression of abnormal behaviour and can provide rapid insight into the welfare of individual animals.

Prevalence of and risk factors for colic in horses that display crib-biting behaviour

Background

Crib-biting and windsucking (CBWS) behaviour in horses has been associated with increased risk of colic in general, recurrence of colic and specific forms of colic. The aims of the present study were to determine the prevalence of colic within a population of horses that display CBWS behaviour and to identify risk factors for colic.

Methods

Owners/carers of horses in the general UK equine population that display CBWS behaviour were invited to participate in a questionnaire-based survey about the management and health of these horses. Data were obtained for a number of variables considered to be possible risk factors for colic. The prevalence of colic was calculated and multivariable logistic regression was used to identify associations between horse- and management-level variables for two outcomes of interest: a history of colic ever and a history of colic in the previous 12 months.

Results

Data were obtained for 367 horses. One or more episodes of colic had been observed in 130 horses (35.4%). A total of 672 colic episodes were reported and 13 colic episodes required surgical intervention in 12 horses. Where the horse/pony had been in that persons care over the previous 12 months (n=331), colic had been observed in 67 horses (20.2%) during that time. A total of 126 colic episodes were reported in the preceding 12 months of which veterinary attendance was required in 69 (54.8%) episodes. Increased duration of ownership, increased duration of stabling in the Autumn months (September-November), crib-biting/windsucking behaviour associated with eating forage and horses that were fed haylage were associated with increased risk of colic (ever). Increasing severity (frequency) of CBWS behaviour and increased duration of stabling in the Autumn were associated with increased risk of colic in the previous 12 months.

Conclusions

The prevalence of colic in a population of horses that display CBWS appeared to be relatively high. The results of this study can be used to identify horses that display CBWS who are at increased risk of colic and identifies areas for further research to determine if there are ways in which this risk might be reduced.

Effects of feed on plasma leptin and ghrelin concentrations in crib-biting horses

The reason why some horses begin an oral stereotypy such as crib-biting is not known. The aim of this study was to measure ghrelin and leptin concentrations in plasma concentrations to determine whether there is a link to crib-biting in horses. Plasma samples (n=3) were collected for plasma leptin and ghrelin assay before and during the morning first feeding in the usual environments of 15 horses with stereotypic crib-biting and 15 matched controls. The crib-biting intensity was scored in three 5-min phases, and a subgroup of verified crib-biters (n=8) was defined as horses that were seen to crib-bite during this study. Plasma leptin concentration (mean and 95% confidence interval [CI]) was lower in horses observed to crib-bite before and after feeding of concentrates (1.2, CI 0.8-1.7 ng/mL and 1.0, CI 0.6-1.7) than in non-crib-biters (2.3, CI 1.6-3.4 and 2.3, CI 1.6-3.4 ng/mL, respectively) and correlated negatively with crib-biting intensity. Crib-biting intensity was significantly higher shortly after feeding than before or 30 min later. Plasma ghrelin concentration was significantly higher before feeding concentrate than before hay feeding or after the concentrate, but did not differ between groups. There was a significant negative correlation between body composition score and plasma ghrelin concentration. These findings suggest that leptin concentrations may be associated with crib-biting behaviour in horses.