Economic selection indexes for Hereford and Braford cattle raised in southern Brazil

Abstract

Economic selection indexes (EI) are considered the best way to select the most profitable animals for specific production systems. Nevertheless, in Brazil, few genetic evaluation programs deliver such indexes to their breeders. The aims of this study were to determine the breeding goals (BG) and economic values (EV, in US$) for typical beef cattle production systems in southern Brazil, to propose EI aimed to maximize profitability, and to compare the proposed EI with the currently used empirical index. Bioeconomic models were developed to characterize 3 typical production systems, identifying traits of economic impact and their respective EV. The first was called the calf-crop system and included the birth rate (BR), direct weaning weight (WWd), and mature cow weight (MCW) as selection goals. The second system was called the full-cycle system, and its breeding goals were BR, WWd, MCW, and carcass weight (CW). Finally, the third was called the stocking and finishing system, which had WWd and CW as breeding goals. To generate the EI, we adopted the selection criteria currently measured and used in the empirical index of PampaPlus, which is the genetic evaluation program of the Brazilian Hereford and Braford Association. The comparison between the EI and the current PampaPlus index was made by the aggregated genetic-economic gain per generation (Δ). Therefore, for each production system an index was developed using the derived economic weights, and it was compared with the current empirical index. The relative importance (RI) for BR, WWd, and MCW for the calf-crop system was 68.03%, 19.35%, and 12.62%, respectively. For the full-cycle system, the RI for BR, WWd, MCW, and CW were 69.63%, 7.31%, 5.01%, and 18.06%, respectively. For the stocking and finishing production system, the RI for WWd and CW was 34.20% and 65.80%, respectively. The Δ for the calf-crop system were US$6.12 and US$4.36, using the proposed economic and empirical indexes, respectively. Respective values were US$19.87 and US$18.22 for the full-cycle system and US$20.52 and US$18.52 in the stocking and finishing system. The efficiency of the proposed EI had low sensitivity to changes in the values of the economic and genetic parameters. The 3 EI generated higher Δ when using the proposed economic weight compared to the Δ provided by a PampaPlus index, suggesting the use of proposed EI to obtain greater economic profitability in relation to the current empirical PampaPlus index.

Towards a new phenotype for tick resistance in beef and dairy cattle: a review

“…Nonetheless, bio-economic modelling of tick parasitism and epidemiology for specific cattle-production systems and environments is challenging and scarce in the recent livestock literature (Grisi et al 2014;Mapholi et al 2014). Recent work from Brazil, using a stochastic model to account for death risk and reduced productivity, has demonstrated a low importance for tick counts in a global breeding objective, with values of 12.9% for Brangus (Simoes 2017) and 3.8% for Hereford and Braford cattle (Costa et al 2018). However, these values were derived under production systems in subtropical environments where ticks (and, therefore, tickborne diseases) were controlled without major difficulties by chemical treatments and appropriate management.…”

Economic values and selection index in different Angus‐Nellore cross‐bred production systems

“…In Brazil, the use of bioeconomic modelling remains limited, primarily because many farmers do not perform the orderly control of zootechnical herd information, nor of expenses and revenues in their production systems. However, several studies have demonstrated the potential use of these models in multiple trait selection, allowing to define and organize all information of the production system and to support the selection (Bittencourt, Lôbo, & Bezerra, ; Campos et al., ; Costa, Teixeira, Yokoo, & Cardoso, ; Jorge, Cardoso, & De Albuquerque, ; Laske et al., ).…”