Uso de diferentes misturas minerais para vacas de corte: Estudo de caso

Abstract

This study evaluated the economic and reproductive aspects of beef cows raised in tropical pastures and submitted to two different daily intake of phosphorus present in two mineral supplements during the period from 2012 to 2014. The fertility rate and the rate of pregnancy after time fixed artificial insemination were measured in more than five hundred beef cows during the experimental period. At the beginning and at the ending of breeding season fifteen cows were submitted to the needle test to evaluate the bone resistance. Monthly the total costs and the intake of mineral supplements were measured and registered in a spreadsheet. There was no difference in the reproductive parameters when cows were fed with commercial supplement (3,8 gP/day) or a selective mineral supplement (0,39 gP/day). However, the annual cost with commercial supplement was 203,9 @ of beef cattle whereas the selective supplement was only 51,4@. During the time where the herd was supplemented with selective mineral mixture, there was no sign of mineral deficiency; e.g. phosphorus deficiency.