SUBSTITUIÇÃO DO FARELO DE SOJA POR URÉIA NA SUPLEMENTAÇÃO DE VACAS LEITEIRAS NO SERTÃO PERNAMBUCANO

Abstract

The objective of this experiment was evaluate the effect of nitrogen nonproteic (NNP), that is urea and ammonia sulphate, replace to soybean meal in the supplementation of milk cows fed with differed buffel grass and cactus forage. The work was carried out at IPA - Experimental Station in Serra Talhada - PE. Eight cows were fed in a 7.5 ha area, four from the Guzera race and four from the 5/8 Holstein/Zebu. They were supplied with 38 kg of cactus forage (P) and soybean meal (FS), being replaced by urea + ammonia sulphate (U+SA). The experimental design was the Latin Square, and the treatments were P + FS (1.69 kg FS); P + 2/3FS + 1/3U (1.13 kg FS + 97 g U+SA); P + 1/3FS + 2/3U (0.56 kg FS + 195 g U+SA) e P+U (292 g U+SA). The 5/8 Holstein/Zebu cows were more productive than the Guzera, with the production of 7.08 and 7.31 against 4.67 and 5.34 kg/day, respectively, for milk and corrected milk for 4% of fat. There was no difference among the treatments or interaction race x treatment, so that the NNP could substitute soybean meal in the conditions of developed experiment.