Determining Objective Parameters to Assess Gait Quality in Franches-Montagnes Horses for Ground Coverage and Over-Tracking - Part 1: At Walk

Burren

2022

Animals

Self Cite

Conformation traits such as joint angles are important selection criteria in equine breeding, but mainly consist of subjective evaluation scores given by breeding judges, showing limited variation. The horse shape space model extracts shape data from 246 landmarks (LM) and objective joint angle measurements from triplets of LM on standardized horse photographs. The heritability was estimated for 10 joint angles (seven were measured twice with different LM placements), and relative warp components of the whole shape, in 608 Franches-Montagnes (FM) horses (480 stallions, 68 mares and 60 geldings born 1940–2018, 3–25 years old). The pedigree data comprised 6986 horses. Genetic variances and covariances were estimated by restricted maximum likelihood model (REML), including the fixed effects birth year, age (linear and quadratic), height at withers (linear and quadratic), as well as postural effects (head, neck, limb position and body alignment), together with a random additive genetic animal component and the residual effect. Estimated heritability varied from 0.08 (stifle joint) to 0.37 (poll). For the shape, the type was most heritable (0.36 to 0.37) and evolved from heavy to light over time. Image-based phenotyping can improve the selection of horses for conformation traits with moderate heritability (e.g., poll, shoulder and fetlock).

Section: Discussionmentioning

confidence: 99%

Estimates of Genetic Parameters for Shape Space Data in Franches-Montagnes Horses

Burren

2022

Animals

Self Cite

“…The higher extreme showed a horse shape with a roach back and sloping croup, as opposed to the lowest extreme of a sway-backed horse (hyperlordosis) with a horizontal croup, although we have no information on actual clinical signs in this dataset of horse photographs. Follow-up studies should include radiographs of genotyped horses with extreme roach back or sway back, as well as an objective movement analysis of homozygous horses from both genotype groups to determine whether the conformation would affect the gait quality of the horse, as stride length and over-tracking distance are highly dependent on the movement of the pelvis at walk, and to a lesser extent, at trot 43,44 . Previous genomic research investigated juvenile onset lordosis in the American Saddlebred horse identifying a large haplotype on ECA20 potentially involving the TRERF1, TAF8 and C6orf132 genes 45 .…”

Section: Discussionmentioning

confidence: 99%

New Genomic Insights into the Conformation of Lipizzan Horses

Brem

2023

Preprint

Self Cite

Conformation traits are important selection criteria in equine breeding, as they describe the exterior aspects of the horse (height, joint angles, shape). However, the genetic architecture of conformation is not well understood, as data of these traits mainly consist of subjective evaluation scores. Here, we performed genome-wide association studies (GWAS) on two-dimensional (2D) shape data of Lipizzan horses. Based on this data, we identified two significant quantitative trait loci (QTL) related to a heavy or light type of horse on equine chromosome (ECA) 16 within the MAGI1 gene and on ECA5 within the POU2F1 gene. Both genes were previously described to affect growth and muscling in sheep, cattle and pigs. Furthermore, we pin-pointed another suggestive QTL on ECA 21, near the PTGER4 gene, associated with human ankylosing spondylitis, for shape differences in the back and pelvis (roach back vs sway back). Further differences in the shape of the back and abdomen were suggestively associated with the RYR1 gene, involved in core muscle weakness in humans. Therefore, we demonstrated, that horse shape space data enhance the genomic investigations of horse conformation.

“…The higher extreme showed a horse shape with a roach back and sloping croup, as opposed to the lowest extreme of a sway backed horse (hyperlordosis) with a horizontal croup, although we have no information on actual clinical signs in this dataset of horse photographs. Follow-up studies should include radiographs of genotyped horses with extreme roach back or sway back, as well as an objective movement analysis of homozygous horses from both genotype groups to determine whether the conformation would affect the gait quality of the horse, as stride length and over-tracking distance are highly dependent on the movement of the pelvis at walk, and to a lesser extent, at trot 47 , 48 . Previous genomic research investigated juvenile onset lordosis in the American Saddlebred horse identifying a large haplotype on ECA20 potentially involving the TRERF1 , TAF8 and C6orf132 genes 49 .…”

Section: Discussionmentioning

confidence: 99%

New genomic insights into the conformation of Lipizzan horses

Brem

2023

Sci Rep

Conformation traits are important selection criteria in equine breeding, as they describe the exterior aspects of the horse (height, joint angles, shape). However, the genetic architecture of conformation is not well understood, as data of these traits mainly consist of subjective evaluation scores. Here, we performed genome-wide association studies on two-dimensional shape data of Lipizzan horses. Based on this data, we identified significant quantitative trait loci (QTL) associated with cresty neck on equine chromosome (ECA)16 within the MAGI1 gene, and with type, hereby differentiating heavy from light horses on ECA5 within the POU2F1 gene. Both genes were previously described to affect growth, muscling and fatty deposits in sheep, cattle and pigs. Furthermore, we pin-pointed another suggestive QTL on ECA21, near the PTGER4 gene, associated with human ankylosing spondylitis, for shape differences in the back and pelvis (roach back vs sway back). Further differences in the shape of the back and abdomen were suggestively associated with the RYR1 gene, involved in core muscle weakness in humans. Therefore, we demonstrated that horse shape space data enhance the genomic investigations of horse conformation.