Avaliação do desempenho ao primeiro parto de fêmeas Nelore e F1
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Data
1999-08-01
Autores
Pelicioni, Luciele Cristina [UNESP]
Muniz, Carolina Amália de Souza Dantas [UNESP]
Queiroz, Sandra Aidar de [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Zootecnia
Resumo
O objetivo deste estudo foi comparar o desempenho ao primeiro parto de fêmeas Nelore e mestiças F1. Os dados usados são referentes a 741 partos de fêmeas Nelore e F1, nascidas do acasalamento de vacas Nelore com touros das raças Aberdeen Angus, Brangus (pelagens preta e vermelha), Canchim, Nelore, Gelbvieh e Simental, nascidas entre 1989 e 1993. As informações referentes a 566 bezerros nascidos entre 1991 e 1995, do acasalamento dessas fêmeas com touros Aberdeen Angus, Brangus, Nelore, Simental, Gelbvieh, Charolês, Guzerá e Canchim foram também incluídas na análise. As características estudadas foram idade ao primeiro parto (IPP) das vacas e ganho médio diário de seus bezerros no período pré-desmama (GMD). As características foram analisadas pelo método dos quadrados mínimos, usando-se modelos fixos que incluíram os efeitos IPP: grupo contemporâneo (GC), grupo genético da vaca (GGV), classe de peso à desmama (CP) e interação GGV e CP e GMD: GGV, GC, grupo genético do bezerro dentro de grupo genético da vaca (GGB[GGV]). As covariáveis idade da vaca ao parto (linear) e idade do bezerro à desmama (linear) foram incluídas no modelo. A comparação entre as médias dos vários grupos genéticos foi feita por meio de contrastes ortogonais. As fêmeas F1 dos grupos 1/2 Angus 1/2 Nelore e 1/2 Brangus Vermelho 1/2 Nelore foram mais precoces ao primeiro parto (29,7 e 30,3 meses, respectivamente) que as dos demais grupos genéticos. As vacas Nelore e F1 não diferiram quanto ao desempenho pré-desmama de seus bezerros.
The objetive of this study was to compare the first calving performance of Nellore and F1 crossbred cows. Data used in the study came from 741 calving of Nellore and F1 cows born from the matting of Nellore cows with sires of the breeds Aberdeen Angus, Brangus (black and red), Canchin, Nellore, Gelbvieh and Simental born from 1989 to 1993. The information about 566 calves born from 1991 to 1995, from the matting of these females with the Aberdeen Angus, Brangus, Nellore, Simental, Gelbvieh, Charolais, Guzera and Canchin were also included in the analysis. The studied traits were age at first calving (AFC) of cows and pre weaning average daily gain (PDG) of their calves. The traits were analyzed by the least squares method using a fixed model that included the AFC effects: contemporary group (CG), genetic group of cow (GG), weaning weight class (WC), and the interaction GG and WC, and PDG:GG; CG, genetic group of calf within the genetic group of cow (GGC [GG]). The covariates age of cow at calving (linear) and age of calf at weaning (linear) were included in the model. The comparison among the means of several genetic groups was made by means of orthogonal contrasts. The F1 females from the groups 1/2 Angus 1/2 Nellore and 1/2 Red Brangus 1/2 Nellore were youngier at the first calving (29.7 and 30.3 months, respectively) than the others genetic groups. The Nellore and F1 cows did not differ as the pre weaning performance of their calves.
The objetive of this study was to compare the first calving performance of Nellore and F1 crossbred cows. Data used in the study came from 741 calving of Nellore and F1 cows born from the matting of Nellore cows with sires of the breeds Aberdeen Angus, Brangus (black and red), Canchin, Nellore, Gelbvieh and Simental born from 1989 to 1993. The information about 566 calves born from 1991 to 1995, from the matting of these females with the Aberdeen Angus, Brangus, Nellore, Simental, Gelbvieh, Charolais, Guzera and Canchin were also included in the analysis. The studied traits were age at first calving (AFC) of cows and pre weaning average daily gain (PDG) of their calves. The traits were analyzed by the least squares method using a fixed model that included the AFC effects: contemporary group (CG), genetic group of cow (GG), weaning weight class (WC), and the interaction GG and WC, and PDG:GG; CG, genetic group of calf within the genetic group of cow (GGC [GG]). The covariates age of cow at calving (linear) and age of calf at weaning (linear) were included in the model. The comparison among the means of several genetic groups was made by means of orthogonal contrasts. The F1 females from the groups 1/2 Angus 1/2 Nellore and 1/2 Red Brangus 1/2 Nellore were youngier at the first calving (29.7 and 30.3 months, respectively) than the others genetic groups. The Nellore and F1 cows did not differ as the pre weaning performance of their calves.
Descrição
Palavras-chave
Beef cattle, Crossbreeding, Preweaning average daily gain, age at first calving, Bovinos de corte, cruzamento, ganho médio diário pré-desmama, Idade ao primeiro parto
Como citar
Revista Brasileira de Zootecnia. Sociedade Brasileira de Zootecnia, v. 28, n. 4, p. 729-734, 1999.