ANÁLISE ECONÔMICA DA ALIMENTAÇÃO DE VACAS LEITEIRAS COM CANA-DE-AÇÚCAR CORRIGIDA COM FARELO DE SOJA OU URÉIA

The objective of this trial was to economically compare a sugarcane plus soybean meal diet with diets containing sugarcane supplemented with increasing levels of a 9:1 premix of urea and ammonium sulphate (0.4, 0.8% and 1.2%). Cows were maintained in tie stalls and were fed ad libitum twice a day. The forage to concentrate ratio in the beginning of the experiment was 55:45 supplemented with 1 kg/day of concentrate for each 2 kg of milk produced. Animals were blocked by days in milk and randomly assigned to treatments in three replicated 4 x 4 Latin squares. The average prices of feedstuffs in the state of Minas Gerais during the year of 2004 were used in the economical analyses. Supplementation of sugarcane with 1.2% of urea plus ammonium sulphate appears to be best the best economical compromise for lactating dairy cows producing up to 20 kg of milk per day.