The objective of this experiment was to evaluate the performance of crossbred Charolais x Nellore young steers fed diets with different corn hybrid silage: Agroceres AG9090, Dekalb DK440 or Braskalb XL344. Animals were feedlot finished until reaching approximately 430 kg of body weight. The average age of the animals at the beginning and at the end of the trial was 10.3 and 15.2 months, respectively. Diets were formulated to contain a forage:concentrate ratio of 60:40 (DM basis) with the following crude protein and energy contents: 9.57% and 3.024 Mcal/kg DM for AG9090, 9.36% and 3.181 Mcal/kg DM for DK440, and 9.46% and 3.173 Mcal/kg DM for XL344. A split plot approach with repeated measures over time in a completely randomized design was used. The silage dry matter content of the corn hybrid XL344 (44.32%) was greater than that of DK440 (37.63%) and AG9090 (35.22%). Silages of DK440 and XL344 hybrids had higher energy density than that from the AG9090. Feeding young steers DK440 and XL344 silages resulted in linear decreases in the daily intakes of DM (DMI), DE (DEI) and NDF (NDFI), expressed as percentage of body weight (% BW) and per unit of metabolic weight (UMW), as the feeding period progressed. The same was observed for animals fed the AG9090 silage except that no linear effect was observed for NDFI when expressed as UMW. A significant interaction between corn hybrid and feeding period was observed for average daily weight gain (ADG). Body condition, daily body condition gain and conversion of feed and energy were similar among animals fed the different corn hybrids silage. Final thoracic perimeter, final length, and final thoracic and final length daily gains were all significantly correlated with performance variables. Similar animal production was observed for DK440, XL344, and AG9090 silages.
body measurements; corn silage; feed conversion; intake; slaughter age; weight gain
