Selection for higher body weight in Nelore cattle is effective in achieving an increase of longissimus muscle area without reducing subcutaneous fat thickness

AUTOR(ES)

Pinheiro, Tiago Roque, Mercadante, Maria Eugênia Zerlotti, Albuquerque, Lucia Galvão de, Bonilha, Sarah Figueiredo Martins, Monteiro, Fábio Morato

FONTE

Revista Brasileira de Zootecnia

DATA DE PUBLICAÇÃO

2012-06

RESUMO

The objectives of this study were to estimate heritabilities and genetic and phenotypic correlations between carcass traits measured by ultrasound and other economically important traits generally used as selection criteria in beef cattle and to estimate the genetic changes in the carcass traits as a result of selection for post-yearling weight. Carcass traits measured by ultrasound at two ages (12 and 18 months) and the correlation of these traits with weight, hip height and body condition score of males (yearling) and females (post-yearling) were analyzed. Multi-trait analysis was performed using the restricted maximum likelihood method under an animal model. To demonstrate the effect of selection for growth, phenotypic and expected breeding value means of the carcass traits and weights according to selection line (Nellore control line, selection line and traditional line) were estimated using records from animals born in the last 3 years (2006 to 2008). The heritability estimates were high for longissimus muscle area (LMA) at 12 and 18 months of age (0.47 and 0.40, respectively). For fat thickness measures, heritabilities ranged from 0.37 to 0.29. Genetic correlations of the same trait between the two ages were high for LMA (0.95). The Nellore breed shows medium to high genetic variability in carcass traits measured by ultrasound at 12 and 18 months of age, and a greater response is expected if selection for backfat thickness is performed at about 12 months of age. Selection for higher body weight will lead to an increase of LMA at the two ages without reducing subcutaneous fat thickness.

Documentos Relacionados

• Response to Selection for Body Weight and Egg Weight in Chickens
• NCAPG is differentially expressed during longissimus muscle development and is associated with growth traits in Chinese Qinchuan beef cattle
• Sample size for body weight in beef cattle in repeated measurements experiments.
• Responses to Selection for Body Weight in Descendants of X-Irradiated Rats
• Reducing hypothalamic AGRP by RNA interference increases metabolic rate and decreases body weight without influencing food intake