Energia e fósforo na alimentaçao de novilhas em crescimento

The effects of two levels of energy and phosphorus on growth and reproductive performance of 36 heifers (24 7/8 Holstein x Zebu and 12 Holstein) 450 days old weighing 180 kg, were studied. On a randomized completely design the treatments were arranged on a 2 x 2 factorial method: energy intakes of 11.86 and 13.00 ME/day and levels of phosphorus in the ration 0.31 and 0.41 percent. Heifers were feed sorghum silage ground ear corn and soybean oil meal and were supplied with minerals and water ad libitum. The increase in energy intake, reduced the age at puberty and also increased daily weight gain (P < 0.05). However there was no effect (P > 0.05) on the age of mating and the weight at puberty or at mating, dry matter intake or reproductive performance. The phosphorus levels did not affect (P > 0.05) age or weight at puberty or at mating, daily weight gain dry matter intake and reproductive performance. (RA) eng