Factor Analysis of Genetic Parameters for Body Conformation Traits in Dual-Purpose Simmental Cattle

Abstract

In this study, we estimated the genetic parameters for 6 composite traits and 27 body conformation traits of 1016 dual-purpose Simmental cattle reared in northwestern China from 2010 to 2019 using a linear animal mixed model. To integrate these traits, a variety of methods were used as follows: (1) genetic parameters estimates for composite and individual body conformation traits based on the pedigree relationship matrix (A) and combined genomic-pedigree relationship matrix (H); (2) factor analysis to explore the relationships among body conformation traits; and (3) genetic parameters of factor scores estimated using A and H, and the correlations of EBVs of the factor scores and EBVs of the composite traits. Heritability estimates of the composite traits using A and H were low to medium (0.07–0.47). The 24 common latent factors explained 96.13% of the total variance. Among factors with eigenvalues ≥ 1, F1 was mainly related to body frame, muscularity, and rump; F2 was related to feet and legs; F3, F4, F5, and F6 were related to teat placement, teat size, udder size, and udder conformation; and F7 was related to body frame. Single-trait analysis of factor scores yielded heritability estimates that were low to moderate (0.008–0.43 based on A and 0.04–0.43 based on H). Spearman and Pearson correlations, derived from the best linear unbiased prediction analysis of composite traits and factor scores, showed a similar pattern. Thus, incorporating factor analysis into the morphological evaluation to simplify the assessment of body conformation traits may improve the genetics of dual-purpose Simmental cattle.

Estimation of genetic parameters of claw formation in Holstein and Slovak Spotted cattle

“…Susanto et al (2018) reported phenotypic variation for claw angle at level 9.9% in Holstein dairy cows. Xu et al (2022) found a lower coefficient of variation in Simmental breed, ranging between 20.0% and 22.4%. Variability of the observed claw conformation traits could be affected by genetic effects, gene variation, environmental effects (herd, order of lactation, calving season), but also by the type of floor (Burgi et al, 2017), and individuality of evaluated animals (Canatan et al, 2021).…”

Identifying the Most Important Linear Body Depth Traits Associated with Milk Yield in Dairy Cattle

“…It could be affected by the same factor as mentioned before. Next, the body depth is 72 -82 cm (ZAVADILOVÁ et al 2009) or 61 -90 cm (XU et al 2022). At the same time, the udder depth (UDD) has a reference distance of -19 to 22 cm (XU et al 2022).…”

“…Next, the body depth is 72 -82 cm (ZAVADILOVÁ et al 2009) or 61 -90 cm (XU et al 2022). At the same time, the udder depth (UDD) has a reference distance of -19 to 22 cm (XU et al 2022). BDD and UDD traits are positioned on the standard interval data because the cattle breed sample between current exploration and references are similar.…”

Enhancing Genomic Prediction Accuracy for Body Conformation Traits in Korean Holstein Cattle

“…RAN was genetically correlated with calving interval at −0.16 [27]. Extensive research on the genetic correlation between body conformation traits and somatic cell scores revealed the strongest associations with FUA, FTP, and UDE [28].…”