Twenty-seven growing buffaloes of Mediterranean breed were maintained in feedlot for about 140 days with the objective to evaluate the effects of energy intake on the performance and blood serum concentrations of glucose, total protein and urea. The treatments were constituted of three different levels of energy intake: LE (Low Energy), RE (Required Energy) and HE (High Energy). RE was calculated with 125 kcal/kg0.75/day of metabolizable energy for maintenance; LE with 20% below and HE with 20% above of this level, adopting gain average daily of 800 g, corresponding to 10 kcal of EM/g of gain for animal up to 250 kg plus 0.02 kcal/kg of weight above 250 kg/g of gain. Blood samples were collected in three periods: 44, 66 and 88 days after beginning of the experiment. There were significant differences in the average weight daily gain among LE (773.9 g), RE (942.8 g) and HE (1071.8 g) and urea blood serum level. Average dry matter intake (g/kg0.75) and metabolizable energy estimated (Mcal/animal/day) were, respectively: 89.54 and 17.13 to LE, 92.87 and 18.24 to RE and 95.66 and 20.94 to HE. Based on the obtained weight gain and metabolizable energy daily quantity ingested, it was concluded that the total requirement of metabolizable energy for growing buffaloes recommended by KEARL (1982) finds overestimated on an average of 14.73%.
buffalo; energy; feedlot; performance; requirement
