Associations of health status and conformation with longevity and lifetime competition performance in young Swedish Warmblood riding horses: 8,238 cases ( 1983-2005)

Journal of the American Veterinary Medical Association
June 15, 2014, Vol. 244, No. 12, Pages 1449-1461

Lina Jönsson, PhD; Agneta Egenvall, DVM, PhD; Lars Roepstorff, DVM

Design—Cohort study and genetic analysis.

Animals—8,238 horses.

Procedures—Horses were examined for health, conformation, and performance from 1983 to 2005, when they were 4 to 5 years old, and competition results from 1983 to 2012 were evaluated. Associations between conformation, health, and talent scores of young horses and longevity (years in competition) and lifetime performance were analyzed. Odds ratios of competing later in life among horses with joint flexion test reactions were determined. Genetic correlations between young horse health, conformation, and talent scores and longevity and lifetime performance were determined.

Results—Good overall 4- to 5-year-old health, conformation, and talent scores for performance were phenotypically and genetically associated with greater longevity and lifetime performance. Good health was genetically correlated (rg = 0.3) to longevity and lifetime performance. Among conformation traits, body type and movements in the trot were most strongly associated with future longevity; these were genetically correlated (rg = 0.2 to 0.3) to longevity and lifetime performance. Intermediate-sized horses were associated with highest longevity and lifetime performance. Positive flexion test results were associated with lower ORs (OR, 0.59 for moderate to severe and 0.76 for minor reactions) of competing later in life, compared with no reaction, and were associated with lower longevity (0.4 years).

Conclusions and Clinical Relevance—Horses with good health and conformation at a young age had better longevity in competitions than the mean. Positive correlations suggested that improvement of health and conformation of young horses will enhance their future athletic talent and performance.


The effect of hay net design on rate and amount of forage consumed by adult horses

K. Martinson, E. Glunk and W. Weber
Description of the problem

Horses have evolved to consume several small forage-based meals throughout the day, often spending greater than 14.5 hours grazing each day. However, many of today’s horses are housed in boxstalls or drylots, fed two large meals each day, and have limited opportunity to forage. To mimic a more natural feeding pattern many horse owners provide unlimited access to hay. In many cases, this results in obesity because the horses tend to consume hay in excess of their energy requirement. Therefore, it is of interest to identify feeding methods that reduce excess intake, but extend the foraging period beyond a few hours around meal time.

To investigate the effect of hay net design on the rate and amount of forage consumed by adult horses.
Materials and methods

Eight adult horses in were fed in individual boxstalls. Horses were fed hay off the boxstall floor (control), or from one of three hay nets: large net (6 inch openings), medium net (1.75 inches) and small net (1.0 inch). Horses were acclimated to their assigned treatment for 2 days, followed by 3 days of data collection, and a wash-out period of 2 days. Horses had access to hay inside the nets for two 4hour periods: 7:00 to 11:00 am and 4:00 to 8:00 pm each day. Throughout the trial, grass hay was fed at 1% body weight twice each day. To determine forage consumption rate, stopwatches were started once horses began eating, and stopped once horses either finished all offered hay, were no longer interested in eating, or the 4 hour time period had expired. All refuse hay was collected and weighed. Total forage consumed was calculated by subtracting amount of refuse from hay offered.

Mean consumption rates were 3.3, 2.9, 2.4, and 1.9 pounds per hour for the control, large net, medium net and small net respectively. Horses were able to consume all hay from the control and large during the 4hour feeding period, but not all horses finished the hay meal when fed from the medium and small nets. Mean percentage of offered hay consumed was 95, 95, 89 and 72% for the control, large net, medium net and small net, respectively. A second study revealed that horse feeding from the medium net took just over 5 hours to consume the hay meal, while horses eating from the small nets took 6.5 hours to consume the meal. Both the control and large net resulted in consumption times of 3.2 and 3.4 hours, respectively.
Benefits to the equine industry

These results demonstrate that the small or medium nets were effective in decreasing rate and amount of forage consumed and increasing the total time of forage consumption by adult horses. If small or medium hay nets were used for twice daily feedings in a boxstall setting, the anticipated amount of time horses would spend foraging would be 10 to 13 hours each day; more closely mimicking a horse’s natural grazing behavior. Small and medium hay nets represent simple and affordable management tools for extending foraging time when meal feeding horses. However, use of the small and medium hay nets is not likely practical for all horses and it does take time (usually 4 to 5 feedings) for horses to acclimate to feeding from the nets.


Equine-assisted activities and the impact on perceived social support, self-esteem and self-efficacy among adolescents – an intervention

In this project, we examined the effect of a 4-month intervention with horses on perceived social support, self-esteem and general self-efficacy among Norwegian adolescents aged 12-15 years. The intervention took place at farm-based stables and included work with the horses and riding. A waiting-list crossover design was used and the participants answered questionnaires at three time periods. Study I (N = 49) examined the effect of the intervention compared with the control group. Study II (N = 41) examined the relationship between the same psychological variables and change in mastering skills with horse. The intervention group reported a significant increase in perceived social support compared with the control group. There were no differences in self-esteem and general self-efficacy between the groups. The results from study II showed that a lower level of perceived social support prior to the intervention predicted an increase in mastering skills with the horse during the intervention.
adolescents; equine-assisted activities; horses; intervention; social support.


Effects of intrabursal administration of botulinum toxin type B on lameness in horses with degenerative injury to the podotrochlear apparatus

Santiago D. Gutierrez-Nibeyro, DVM, MS; Marcos P. Santos, DVM.

Objective—To determine the safety and short-term efficacy of intrabursal administration of botulinum toxin type B (BTXB) to alleviate lameness in horses with degenerative injury to the podotrochlear apparatus (PA).

Animals—10 Quarter Horses with degenerative injury to the PA.

Procedures—Degenerative injury to the PA was confirmed with diagnostic analgesia and imaging. Then, BTXB (3.8 to 4.5 U/kg) was injected into the podotrochlear (navicular) bursa of each horse. Three horses were used in a safety evaluation. Subsequently, video recordings of lameness evaluations were obtained for 7 client-owned horses 5 days before (baseline) and 7 and 14 days after BTXB treatment and used to determine the effect of BTXB injection on lameness; 1 horse was removed from the study 8 days after BTXB treatment. Three investigators who were unaware of the treated forelimbs or time points separately reviewed the recordings and graded the lameness of both forelimbs of the horses.

Results—Improvement in lameness of the treated forelimbs was detected at 1 or both time points after BTXB administration in all horses. However, all horses had some degree of lameness at the end of the study. Two horses developed transient increases in lameness 48 to 72 hours after treatment; lameness resolved uneventfully.

Conclusions and Clinical Relevance—Intrabursal injection of BTXB temporarily alleviated chronic lameness in horses with degenerative injury to the PA, without causing serious short-term adverse effects. Further investigation into the potential use of BTXB in horses affected by degenerative injury to the PA is warranted.


Influence of emotional balance during a learning and recall test in horses

Modern day horse-human relationships entail different types of sport and riding activities, which all require learning. In evaluating the interaction between learning and emotions, studying normal coping strategies or adaptive responses to the surroundings is critical. 34 horses were involved in a cognitive test, in the absence of physical effort, to analyze performance, as well as physiological and behavioral responses related to learning, memorization and recall, associated to the capacity to reverse a learned model. Synthetic Equine Appeasing Pheromone (EAP) was used in 17 horses in order to modulate their emotional state and evaluate differences in cognitive-emotional response during cognitive effort in comparison to the control group (placebo group). Both groups showed statistically significant changes in heart rate during the test, indicating emotional and physio-cognitive activation. The EAP group produced fewer errors and made more correct choices, showing behaviors related to increased attention, with less influence from environmental stimuli. The capacity to learn to learn, as shown in the bibliography, allows animals to establish conceptual learning, when a normal or positive emotional state (in this case modulated by semiochemicals) is used to control limbic system activation and, consequently, decrease stressful/fearful reactions, resulting in better learning capacities during the cognitive test.