Estimação de parâmetros genéticos para escores visuais e características de desenvolvimento ponderal na raça Nelore

Duitama, L.O.; Fonseca, Ricardo da; Bertipaglia, Tássia Souza; Machado, C.H.; Filho, Cecílio Viega Soares

doi:10.1590/1678-4162-6874

Cited by 8 publications

(5 citation statements)

References 18 publications

(7 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Visual scores evaluated at yearling may respond to the selection process faster and more accurately than those taken at weaning due to the high direct heritability observed and, therefore, should be considered as selection criteria in order to improve the body composition to a desired biotype. Our estimates for BS Y , FP Y , and MS Y were in the range observed in the literature (Duitama et al 2015;Faria et al 2010;Gordo et al 2012).…”

Section: Resultssupporting

confidence: 83%

See 1 more Smart Citation

Evaluation of body weight and visual scores for genetic improvement of Nelore cattle

Paterno

Buzanskas

Filho³

et al. 2016

Trop Anim Health Prod

View full text Add to dashboard Cite

The aims of our study were to estimate genetic parameters for body weight and visual scores and to evaluate their inclusion as selection criteria in the Nelore breeding program in Brazil. The traits studied were the body weight adjusted to 210 (W210) and to 450 (W450) days of age and visual scores for body structure, finishing precocity, and muscling evaluated at weaning (BS, FP, and MS) and yearling (BS, FP, and MS) ages. A total of 33,242, 26,259, 23,075, and 26,057 observations were considered to analyze W210, W450, and visual scores at weaning and yearling. The significant (P < 0.05) fixed effects for all traits were farm, birth season, birth year, sex, and management group. Single-trait analyses were performed to define the most fitting model to our data using the average information restricted maximum likelihood algorithm, for weaning traits. Subsequently, these models were used in single- and two-trait analyses considering the Bayesian inference algorithm. Two-trait Bayesian analyses resulted in average direct heritability estimates for BS, FP, MS, W210, BS, FP, MS, and W450 of 0.28, 0.30, 0.27, 0.28, 0.40, 0.44, 0.39, and 0.50, respectively. Genetic correlations varied from 0.40 to 0.96. Benefits to animal performance can best be achieved by considering body structure, finishing precocity, and muscling as selection criteria in the Nelore breeding programs. The decision to use visual scores measured at weaning should be considered in order to decrease generation interval and assist pre-selecting individuals, expecting carcass improvements in the future progeny.

show abstract

Section: Resultssupporting

confidence: 83%

“…Thus, genetic gains are expected in W210 and W450 when considering visual score traits for selection. Gordo et al (2012) and Duitama et al (2015) observed high genetic correlations of visual scores and body weight traits.…”

Section: Resultsmentioning

confidence: 95%

Evaluation of body weight and visual scores for genetic improvement of Nelore cattle

Paterno

Buzanskas

Filho³

et al. 2016

Trop Anim Health Prod

View full text Add to dashboard Cite

show abstract

“…Values of posterior heritability means obtained in this study are consistent with values observed by other authors. Heritability estimates in cattle for weaning weight ranged from 0.11 to 0.25 (Moreira et al, 2015;Santos et al, 2019;Barbosa et al, 2017), from 0.16 to 0.44 for the yearling weight (Moreira et al, 2015;Souza et al 2018;Santos et al, 2019;Barbosa et al, 2017), from 0.17 to 0.44 for post-yearling weight (Moreira et al, 2015;Souza et al, 2018;Santos et al, 2019;Barbosa et al, 2017), and from 0.20 to 0.26 for post-weaning weight gain (Duitama et al, 2015;Santana et al, 2017).…”

Section: Discussionmentioning

confidence: 99%

The impact of heterogeneity of variances on the genetic evaluation of performance traits in Nellore cattle

Menezes¹,

Araújo²,

Novo³

et al. 2022

Revista Brasileira De Zootecnia

View full text Add to dashboard Cite

The objective was to evaluate the existence of heterogeneity of variances and its impact on the genetic evaluation of ponderal performance in sires of the Nellore breed. We used records of adjusted body weights at 210 (W210), 365 (W365), and 450 (W450) days of age. Both W365 and W450 were combined by principal component analyses using the first component (PC). Average daily gain (ADG) was obtained by difference between W450 and W210. The classes of standard deviations (SD) for W210, PC, and ADG were obtained by the standardization of means of herd-year means subclasses, with positive values composing the high SD and values equal and less than zero composing the SD. The model included the fixed effects of contemporary group and age at calving as a covariate, random genetic additive, and maternal genetic (except for PC) effects, and the permanent maternal environment. Variance components were obtained by Gibbs sampling. Posterior means of heritability in analyses without considering heterogeneity of variances ranged from 0.15±0.01 to 0.31±0.01. Posterior means of genetic correlations between the two classes of SD for W210, PC, and ADG were equal to 0.85±0.04, 0.83±0.03, and 0.71±0.08, respectively. Spearman correlation to breeding values of sires for ADG as the selection intensity increased in them, and the correlations between breeding values in general analyses were more correlated with those predicted in the high DP. Therefore, when there is a higher selection intensity on the sires only for the ADG criterion, there is a significant presence of the heterogeneity of variances and impact on the genetic evaluation of the sires. Thus, for ADG, the predictions of breeding values obtained by the genetic evaluation model in which the heterogeneity of variances are not considered are more weighted by the class of greater heterogeneity.

show abstract

“…Most beef cattle breeding programs use growth traits such as weights measured at birth, at weaning and at yearling as selection criteria. Several authors (Chud et al , 2014; Duitama et al , 2015; Gordo et al, 2012; Gordo et al, 2016; Kluska et al, 2018; Schmidt et al, 2018) reported moderate heritability for weights of Nelore cattle reared in tropical regions, indicating genetic progress for growth when the animals are selected for these traits. In addition, other studies showed positive genetic associations between weights and hip height (HH) at different ages (Boligon et al , 2015; Vargas et al , 2000), suggesting that genetic selection exclusively for weight increase will cause changes in the stature and size of animals.…”

Section: Introductionmentioning

confidence: 99%

Genetic analysis of growth, visual scores, height, and carcass traits in Nelore cattle

Silveira

Schmidt

Campos

et al. 2021

Animal Science Journal

View full text Add to dashboard Cite

Covariance components were estimated for growth traits (BW, birth weight; WW, weaning weight; YW, yearling weight), visual scores (BQ, breed quality; CS, conformation; MS, muscling; NS, navel; PS, finishing precocity), hip height (HH), and carcass traits (BF, backfat thickness; LMA, longissimus muscle area) measured at yearling. Genetic gains were obtained and validation models on direct and maternal effects for BW and WW were fitted. Genetic correlations of growth traits with CS, PS, MS, and HH ranged from 0.20 AE 0.01 to 0.94 AE 0.01 and were positive and low with NS (0.11 AE 0.01 to 0.20 AE 0.01) and favorable with BQ (0.14 AE 0.02 to 0.37 AE 0.02). Null to moderate genetic correlations were obtained between growth and carcass traits. Genetic gains were positive and significant, except for BW. An increase of 0.76 and 0.72 kg is expected for BW and WW, respectively, per unit increase in estimated breeding value (EBV) for direct effect and an additional 0.74 and 1.43, respectively, kg per unit increase in EBV for the maternal effect.Monitoring genetic gains for HH and NS is relevant to maintain an adequate body size and a navel morphological correction, if necessary. Simultaneous selection for growth, morphological, and carcass traits in line with improve maternal performance is a feasible strategy to increase herd productivity.

show abstract

Estimação de parâmetros genéticos para escores visuais e características de desenvolvimento ponderal na raça Nelore

Cited by 8 publications

References 18 publications

Evaluation of body weight and visual scores for genetic improvement of Nelore cattle

Evaluation of body weight and visual scores for genetic improvement of Nelore cattle

The impact of heterogeneity of variances on the genetic evaluation of performance traits in Nellore cattle

Genetic analysis of growth, visual scores, height, and carcass traits in Nelore cattle

Contact Info

Product

Resources

About