Animal Science

Abstract

The current breeding program for Lipizzan horses is based on descriptive scoring and linear scoring methods. Because scores are collected for few globally defined traits and phenotypes are selected according to the breeding optimum, the selection process is quite subjective. There has been some development made in the horse personality assessment protocols, but the process has been slow, costly and no reliable methods have been proposed for the practical use. Currently, four methods exist, the questionnaire-based personality assessment method, behavioural tests, personality assessment based on heart rate and the method of grading by anatomical characteristics. Most researchers apply one or two methods, leading us to conclude that there is a lack of a multifactorial approach when looking at individual behaviour differences over time and different contexts. Further, there is a growing body of evidence that supports a genetic background of personality and biomechanics, but there is little clarity around complex interactions between genes and environment that shape personality, psychological disorders and locomotor performance. The third problem is that conformation scoring methods consist of many subjectively defined traits without adequate information on their relative weights. In order to be closer to the process of reliable data collection integrated into the breeding programs, our study will be built on a pilot study already performed on 35 Lipizzan horses, where among others the correlation between cardiovascular activity (heart rate) and anatomical features (i.e., cornet scope of the left front leg and distance between the roots of the ears) was found and between the level of fearfulness and anatomical features (i.e., inferior angle of the nostril or ear width, respectively). We now plan to carry out the study with 200 Slovenian Lipizzan horses at the Stud Farm Lipica. Cardiovascular activity will be measured by means of heart rate when resting, being active (during walk, trot and gallop), and during behavioural tests using Polar V800 heart rate monitor and wristwatch. Four fear-related behavioural tests will be repeated twice in two different days and recorded using video camera. In the passive human test, the horse will be free to initiate an interaction with the motionless unfamiliar handler. In the umbrella test, the handler will lead the horse through a passage between two colourful umbrellas. In the rolling ball test, the handler will lead the horse past the ramp with the blue ball that will be released to roll down past the horse. In the bag test, an assistant will be swinging the whip with a plastic bag for 60 s while the horse will be positioned 5 m from the assistant. To further evaluate anatomical characteristics of Lipizzan horses for a reliable and less subjective measure to define personality traits such as fearfulness, we will collect 138 anatomical measurements on both sides of the head and body using three different approaches, the sartorial meter, the measuring stick and the computer program (tpsDig232 and CoordGen8 software). Next, we will measure 2D limb kinematics using a simple markerbased system to investigate horse biomechanics. Genetic background of assessed phenotypic traits will be analysed using horse high density GGP Equine Plus 72K SNP chip, which will allow us high throughput genotyping of all 200 horses included. Genome association approach will enable identification of genomic regions, associated with formation of physiological, anatomical and behavioural traits. In summary, this interdisciplinary project integrates a genome wide association study and bioinformatics approach for data mining in specialized databases with a clustering methodology based on behavioural, anatomical, and physiological traits. Our key objective is to validate different methods to determine horse personality traits with an emphasis on fearfulness to find the least subjective and reliable method(s) which can be easy to implement under practical conditions by using rigorous statistical approach.

The phases of the project and their realization

A three-year project entitled "Correlating desired phenotypic traits using behavioural, physiological and anatomical features with genetic markers in Lipizzan horse" will take place in Lipica and will include 200 Lipizzaners. It will be divided into four phases and will start in October 2021.

• The first phase of the project will last for the first two months. It will start with group meetings, where the group will get acquainted with the procedures and methodology, and distribute further work. An acronym and logo for the website will be prepared. A list of all necessary equipment and materials will be made and its purchasing will begin. Evaluation forms and protocols for all measurements and tests will be written. Pre-testing will follow, where all tests will be performed on two horses. Based on the observations and pre-tests recordings, all the details for the main testing, which will take place in the next phase, will be finalized.
• The second phase will start in December 2021 and last 10 months (until September 2022). The group will conduct the tests in the field. Measurements of resting heart rate and variability, and body temperature are expected take 7 months. Anatomical measurements of the horses’ bodies and heads are expected to take 2 months, and photography of the head of horses and collection of DNA samples will take 2 weeks.
• The third phase will start in September 2022 and last 9,5 months (until May 2023). This phase will include 5 months of behavioural testing, 1,5 months of measurements of heart rate and variability during and 3 months of biomechanical measurements.

The tasks from the first phase, especially the preparation of the equipment and the familiarisation with the methodology, will also be performed in the second phase before each new activity (e.g., before the start of behavioural tests, before biomechanical measurements, etc.). Ongoing statistical analysis of the collected data will also be performed in the second and third phase.

• The fourth phase, which will include the writing of research documentation, writing of scientific articles and presenting the results, will be completed after all measurements and tests have been completed. The last months will therefore be devoted exclusively to the dissemination of the results.

Project partners

• Jožef Stefan Institute