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| Claus,Luís Afonso Marques; Koetz Júnior,Celso; Roso,Vanerlei Mozaquatro; Borges,Marcelo Henrique Favaro; Barcellos,Júlio Otávio Jardim; Ribeiro,Edson Luis de Azambuja. |
| ABSTRACT This study aimed at estimating the heritability of age at first calving and of performance traits included in the selection index and the genetic correlations between age at first calving and these performance traits. Data were extracted from the Conexão Delta G database and only data from herds in which heifers were bred younger than 24 months of age were used, resulting in a file with 331,310 evaluated animals. The following traits were included in the analyses: age at first calving, birth to weaning gain, post-weaning weight gain, visual scores of conformation, precocity, and muscling evaluated at weaning and in yearling heifers. Covariance components were obtained by bi-character analyses between traits. An alternative age at first calving was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beef cattle; Breeding; Heritability. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000400303 |
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| Koetz Júnior,Celso; Roso,Vanerlei Mozaquatro; Claus,Luís Afonso Marques; Oliveira,Rui Paulo Lopes de; Fávaro,Patrícia da Cruz; Borges,Marcelo Henrique Favaro; Barcellos,Júlio Otavio Jardim; Ribeiro,Edson Luís de Azambuja. |
| ABSTRACT: Mature weight (MW) of cows is related to the costs of their production. Usually, cows with moderate MW are more efficient in challenging environments, such as those available in the production systems in Brazil. In the present study, the selection index comprises the following traits: conformation, finishing precocity, musculature at weaning (WC, WP, WM) yearling (YC, YP and YM), scrotal circumference at yearling (SC), days to gain 160kg from birth to weaning (D160) and 240kg after weaning (D240). This are related to birth weight gain at weaning (WG) and from weaning to yearling (YG). The mature (MW) and birth weight (BW) traits were not considered in the selection index. The aim of this study was to estimate the values for the genetic trends... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beef cattle; Productive traits; Selection. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782017000300652 |
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| Koetz Junior,Celso; Roso,Vanerlei Mozaquatro; Fávaro,Patricia da Cruz; Pereira,Gabriel Ribas; Borges,Marcelo Henrique Favaro; Barca Junior,Flávio Antônio; Barcellos,Júlio Otávio Jardim; Ribeiro,Edson Luis de Azambuja. |
| ABSTRACT This study was intended to estimate the genetic associations between growth traits and visual scores with possible changes in mature weight (MW) in 397,900 Nellore animals. A bi-character analysis was performed to estimate the (co)variances and genetic parameters for MW, which comprises the following traits: conformation, finishing precocity, musculature at weaning (WC, WP, and WM) and yearling (YC, YP, and YM), birth weight (BW), weight from birth to weaning (WG), weight from weaning to yearling (YG), and final index (FIND). The observed mean MW was 417.6±56.2 kg, and the direct genetic effect mean estimated heritability ( h 2 a 1) of MW was 0.45. Overall, the BW was 31.0±3.7 kg, and the estimated h² was 0.34. The heritability estimate of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beef cattle; Growth parameters; Productive traits; Selection. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982019000100301 |
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