Genetic parameters for type traits in Holstein cows in Brazil

Abstract

-Data from 26,558 Holstein cows in 802 herds were used to estimate genetic, residual and phenotypic parameters for 22 type traits. The model included the fixed effects of herd-year, period of classification, classifier, stage of lactation and age of cows at calving (covariate) and random genetic and residual effects. Heritability for type traits ranged from 0.10 to 0.39. The genetic variability in these traits suggested the possibility for moderate genetic gains through selection. The phenotypic correlations were moderated, mainly in the section conformation. Genetic correlations between type traits ranged from -0.44 to 0.85. High genetic correlations indicated that breeding programs could be successful without including all type traits. The selection for the final score at the expense of other traits must be performed with restraint, because in the long term, this may promote undesirable changes in some type traits.

Genetic association between longevity and linear type traits of Holstein cows

“…These results are similar to those reported by Zavadilová and Stípková (2012) in the bivariate analysis of Long5 with stature (0.41), rump width (0.35), teat length (0.27) and foot angle (0.10) and by Darili et al (2008), for stature (0.38). Campos et al (2012) also reported that foot angle (0.10) and udder texture (0.11) were the characteristics that showed the lowest heritability in dairy cows in Brazil.…”

“…Moreover, type traits are usually obtained early on during the productive life; are easy to measure and have higher heritability than longevity, commonly ranging from 0.08 to 0.49 (Daliri et al, 2008;Campos et al, 2012).…”

Genetic associations between reproductive and linear-type traits of Holstein cows in Brazil

“…Moreover, according to Campos et al (2012), the final score reflects the genetic harmony among the all type traits and suggests that these traits can be used as selection criteria to promote improvements in various type traits due to the strong genetic correlation among them.…”

Genetic Association Between Herd Survival and Linear Type Traits in Holstein Cows Under Tropical Conditions

“…The posterior mean of heritability for linear type traits obtained in conjunction with each measure of longevity (Long1_60, Long1_72, Long2_48 and Long2_54) showed low variation, which for the most part were 0.01 and 0.02 points, except for stature (0.04) and body depth, rump angle, foot angle and udder cleft that showed variation of 0.03 (Table 4). Low heritabilities for hoof angle (0.10) and udder texture (0.11) were also observed by Campos et al (2012) in Holstein cows, as well as by Němcová et al (2011) and Lagrotta et al (2010) in Holstein and Gir cattle, respectively, for hoof angle (0.09 and 0.12). The posterior residual correlations were low, ranging from -0.05 to 0.09 (Table 5).…”