As part of a preliminary study on the design of a breeding program involving Holstein Friesian and crossbred cattle (Holstein x Zebu) in the Southeast region of Brazil, economic values for milk volume (V), fat (F) and protein (P) production, age at first calving (AFC), mature body weight (MBW) and herd life (HL) were derived for a pasture based milk production system of crossbred cattle (Holstein x Zebu). The feeding regime was based on rotational grazing of elephantgrass during the rainy season and grazing plus maize silage during the dry season. Concentrates were fed when daily individual productions exceed 6-kg milk (1 kg concentrate: 2.5 kg milk). Sensitivity analyses were carried out to evaluate the effect of the change of payment system and milk price variation on economic values of the traits. Economic values were also derived for an alternative source of roughage supplementation based on the mixture of sugar cane plus urea. The economic values (US$) derived for the current payment system for V, F, P, AFC, MBW and HL were, respectively: 0.15; -0.48; -0.31; -0.11; 0.08 and 0.04. Results of sensitivity analyses are presented and discussed.
genetic improvement; bio-economic models; breeding goal; milk production systems; economic value
