Heritability of Locomotor Stereotypies in Chilean Horses.

The study is focused on identifying if the behaviors of stall-walking and weaving in Chilean horses are inherited. The research found that these behaviors, known as locomotor stereotypies, do seem to have a genetic component but are also significantly influenced by environmental factors.

Overview of the Study

• The study involves just over two thousand Chilean horses who have been stabled for at least a year.
• The owners were asked to provide identification data for each horse and report any observed instances of the horses engaging in stall-walking or weaving—both are known as locomotor stereotypies.
• The genealogy of each horse was obtained from the Chilean Horse Stud Book. This information was used to trace the lineage of each horse to identify if parents passed on the propensity for these behaviors to their offspring.

Results

• The researchers observed a 2.05% prevalence of stall-walking and a 1.43% prevalence of weaving among the sample of horses.
• Both behaviors were more frequently observed in male horses.
• The heritability factor was found to be low for stall-walking (0.213 out of 1) and moderate for weaving (0.435 out of 1). This indicates a genetic basis for these behaviors, but also the significant influence of environmental factors.

Conclusions and Implications

• The research concludes that locomotor stereotypies such as stall-walking and weaving in Chilean horses are genetically influenced to some extent, thus classifying them as hereditary disorders.
• However, the moderate and low heritability factors also suggest that environmental factors play a major role in the prevalence of these behaviors. This could include aspects of the horses’ care, stable conditions, or experiences.