EFFECT OF THE LEVEL OF GICABU IN THE PERFORMANCE OF GRAZING DAIRY HEIFERS

Fifty seven crossbred Holstein calves of 166 kg initial live weight, u ntil calving, were used in completely randomized design to study the e ffect the supplementation with Gicabu in their performance. Treatments consisted of Guinea pasture (Panicum maximum c.v. likoni) and three l evels Gicabu 25, 40 and 55 % in the feed and silage in the second dry season. Feed consumption was of 2 kg daily in the dry season and 1 kg in the rainy season. Animals grazed in 8 paddocks and the nitrogen fer tilizer was applied with 100 kg/ha/year. Differences were only found i n daily gain (P < 0.05) between levels of 25 and 55 % of Gicabu in fav or of the lower level (287 vs 392 g) in the second dry season, where s ilage was applied ad libitum. in the rest of the seasons daily gain ra nged between 427 and 607 g. There were no differences in other indicat ors of the performance of heifers between levels of Gicabu. Animals we re gestated at approximately 22 months and with 345 kg of live weight. Three days after calving the weight and age were 415 kg and 31.2 mont hs, respectively. It is concluded, under these conditions and with the feeds studied, that is possible to attain a satisfactory performance in heifers grazing Guinea grass. It is necessary to carry out studies with higher feed intakes, especially with 25 % of Gicabu in order to i ncrease the energy consumption of the ration.