Factor analysis of body measurements in Arabian horses.

The research studied 13 body measurements in 166 Arabian horses to understand the effects of age and gender on these measurements and reduce these multiple measures to fewer, independent common factors through factor analysis. The research suggests these factors could be taken into consideration in selection programs for better-coordinated horses.

Methods and Data Collection

• The study analyzed data from thirteen different body measurements of 166 Arabian horses, with a breakdown of 123 mares and 43 stallions.
• The age range of the animals used in the study was from 49 to 298 months.
• All of the horses belonged to Alzahraa stud, located in Cairo, Egypt.
• A General linear model was employed to investigate the influences of age and gender on these measurements.

Findings: Gender and Age Effects

• The researchers found that gender had a substantial impact on most measured traits excluding neck girth, cannon bone circumference of fore and hind legs, and pastern girth of fore and hind legs.
• Age appeared to significantly affect pastern girths of fore and hind legs and cannon bone circumference of forelegs, but it did not have a significant influence on the remaining measurements.

Correlations and Factor Analysis

• Pearson correlations between measurements, adjusted for age effect, were estimated. These correlations ranged from 0.02 to 0.84 for mares and -0.05 to 0.90 for stallions.
• Factor analysis with promax rotation was conducted for each gender to derive fewer independent common factors. From this analysis, three factors were identified which accounted for 66% and 67% of the total variance in mares and stallions respectively.

Categories of the Extracted Factors

• For mares, the first, second, and third factors generally described body thickness, leg thickness, and general size respectively.
• For stallions, however, these factors seemed to differentiate between general size, leg thickness, and body thickness respectively.
• Thus, according to the study, the three extracted factors for each gender are suggested to define the primary shared sources of variability governing body conformation in Arabian horses.

Implications

• These factors could be incorporated into selection programmes to achieve highly coordinated bodies in pure Arabian horses with fewer measurements required.