PSXII-3 - Estimation of Heritability and Correlation of Functional Traits in the Peruvian Paso Horse (preliminary Studies)

Abstract: Peruvian Paso Horse is recognized for the smoothness and elegance of its gait. Over the years, breeders have been selecting their breeders based on phenotypic characteristics; however, to date, there are no data or estimated values of the heritability of these characters, whether biometric or functional. The objective of this research is to provide the first heritability values for six biometric and three functional traits, as part of the establishment of a genetic selection and improvement program for the breed. For the study, data from 25 females and 8 males (n=33) at ages 6 to 10 years were used for measurements such as: croup height, substernal height, chest width, neck length, tibia femur angle and impulsion. The sharpness (high lift), atranque (unique footfall pattern, wich foot placement and timing between hindfoot and forefoot of the same side, only known in this special ambling gait) and vertical acceleration were measured by filming each horse in "Paso Llano" (a special four-beat gate, only known in Peruvian Paso Horse). Preliminary results were evaluated with Kinovea software (v.0 .9.5) for heritability and phenotypic correlation values (Table 1 and Figure 1), with Jamovi software (v 2.3.0) for statistical parameters, and the mixed model Y_ijk = u + S_i + C_k + e_ijk for movement analysis and heritability estimation by half-sib correlation, where Y_ijk is the biometric and functional observation, S_i the effect of the father, C_j the effect of sex and e_ijk random error. The results show that the heritability estimates for the nine biometric and functional traits vary between 0.08 and 0.84 and are the first ones obtained after a study in the Peruvian Paso Horse breed.