Resumo

KLUYTS, J.F.; NESER, F.W.C.  e  BRADFIELD, M.J.. Proposed economic selection indices for the Simmentaler breed in South Africa. S. Afr. j. anim. sci. [online]. 2007, vol.37, n.2, pp.122-131. ISSN 2221-4062.

The development of economic selection indices for an integrated Simmentaler production system was described. The breeding objective was defined in terms of production-, functional- and product quality traits. Criteria included in the total index were birth- and weaning weight (direct and maternal), final weight, mature cow weight, days-to-calving, backfat thickness, tenderness and marbling. The total merit index was termed as I_t = - 1.60 BW_d - 1.95 BW_m + 2.23 WW_d + 1.75 WW_m - 0.54 FW - 2.01 MCW - 13.21 CD + 4.97 BF - 2.36 T + 12.66 M. The correlation between this index and the aggregate breeding objective was 0.988. The economic superiority of the progeny from the top 40% of animals selected on their ranking in the total index, relative to the average progeny, is expected to be R 119.51.

Palavras-chave : Beef cattle; breeding objectives; product quality; growth; functional traits.

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