Proposed economic selection indices for the Simmentaler breed in South Africa

Abstract

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 IT = – 1.60 BWD – 1.95 BWM + 2.23 WWD + 1.75 WWM – 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.

South African Journal of Animal Science Vol. 37 (2) 2007: pp. 122-131