Research Article

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Weight gain is a key performance trait for beef cat­tle; however, attention should be given to the production costs for better profitability. Therefore, a feed efficiency trait based on per­formance can be an interesting approach to improve performance without increasing food costs. To identify candidate genes and ge­nomic regions associated with residual body weight gain (RWG), we ... more

M.H.A. Santana; R.C. Gomes; Y.T. Utsunomiya; H.H.R. Neves; F.J. Novais; M.N. Bonin; H. Fukumasu; J.F. Garcia; P.A. Alexandre; G.A.Oliveira Junior; L.L. Coutinho; J.B.S. Ferraz
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Beef cattle production requires reproductive efficiency. However, measures of reproductive traits are not usually collected; consequently, correlated traits that could be used as indicators would be useful. We examined associations between measures of reproductive and productive efficiency that could be used as selection indicators. Data from 194 dams of the genetic groups Angus x Nelore ... more

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Selection for the wide range of traits for which most beef breed associations calculate expected progeny differences focus on increasing the outputs of the production system, thereby increasing the genetic potential of cattle for reproductive rates, weights, growth rates, and end-product yield. Feed costs, however, represent a large proportion of the variable cost of beef production ... more

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It is generally accepted that feed intake and growth (gain) are the most important economic components when calculating profitability in a growth test or feedlot. We developed a single post-weaning growth (feedlot) index based on the economic values of different components. Variance components, heritabilities and genetic correlations for and between initial weight (IW), final weight (FW), ... more

R.R. van der Westhuizen; J. van der Westhuizen
Beef cattle; Feedlot profitability; Growth efficiency; Post-weaning growth

The aim of this study was to identify factors influencing profitability in a feedlot environment and to estimate genetic parameters for and between a feedlot profit function and productive traits measured in growth tests. The heritability estimate of 0.36 for feedlot profitability shows that this trait is genetically inherited and that it can be selected for. The genetic correlations between ... more

R.R. van der Westhuizen; J. van der Westhuizen; S.J. Schoeman
Beef cattle; Bos indicus; Carcass traits; Single nucleotide polymorphisms; Tenderness

Data from purebred Brahman steers (N = 467) were used to study the association of single nucleotide polymorphisms (SNP) with carcass traits and measures of tenderness. Fall weaned calves were grazed and fed in a subtropical environment and then harvested for processing in a commercial facility. Carcass data were recorded 24 h postmortem. Muscle samples and primal ribs were obtained to measure ... more

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