Avaliação da substituição do milho pelo resíduo seco da extração da fécula de mandioca sobre o desempenho de novilhas mestiças em confinamento

Abstract

The objective of this trial was to evaluate the total replacement of corn with a dry residue extracted from cassava starch on production of crossbred heifers in feedlot. Thirty crossbred heifers averaging 21 months of age and 325 kg of body weight were distributed in two experimental groups and then housed in two stalls. Both groups were submitted to a pretrial period of 49 days, in which animals received ad libitum sorghum silage and 1.05% of body weight as concentrate (19.67% CP) composed of soybean meal, corn, and urea. In this period, daily weigh gain (DWG) averaged 1.08 kg for both groups. The experimental period lasted 57 days with animals averaging 378 kg of body weight. At the beginning of the experimental period, one group remained receiving the pre-trial diet while the other was fed ad libitum sorghum silage and 1.18% of body weight as concentrate (18.12% CP) containing dry cassava byproduct rather than corn. Daily weight gain was significantly higher for heifers fed corn-based concentrate (0.97 kg) compared to those receiving dry cassava byproduct-based concentrate (0.78 kg). In addition, dry matter intake and feed conversion were both lower on heifers fed the diet containing dry cassava byproduct. © 2006 Sociedade Brasileira de Zootecnia.