Resumen

SANTOS, Davi Teixeira dos et al. Energy supplements for beef heifers rearing at annual pastures: animal performance. R. Bras. Zootec. [online]. 2005, vol.34, n.1, pp. 209-219. ISSN 1806-9290.  http://dx.doi.org/10.1590/S1516-35982005000100025.

It was evaluated beef heifers performance from three until twelve months of age, when they were reared in cultivated pasture soon after their weaning (experiment 1) and in the first winter post-weaning (experiment 2), with or without the supply of energy supplements to the animals. From 02/16 to 04/21/2001, the heifers stayed in Pearl Millet pasture, exclusively under grazing (PAST₁); supplemented with milled corn grain (PAST₁/C) or supplemented with pellet citric pulp (PAST₁/P). From 07/13 to 10/09/2001, the heifers were maintained in oat plus italian ryegrass pasture without supplementation to the animals (PAST₂); supplemented with milled corn grain (PAST₂/C) or supplemented with soy hull (PAST₂/H). The evaluated variables of animal performance were live weight (LW), average daily gain (ADG) and body condition score (BCS). In the experiment 1, supplemented animals presented larger values of final LW, ADG and BCS in relation to the non supplemented, ones the supplemented treatments not differing to each other. In experiment 2, the soy hull supplemented heifers showed greater ADG and final LW than non supplemented heifers, with the corn grain supplemented group in an intermediary position. The highest BCS was obtained by the animals of PAST₂/H, followed by PAST₂/C and, at last, of PAST₂. Beef heifers weaned at 60-90 days should be supplemented in the initial post-weaning period, enabling them to reach satisfactory development in this phase of growth. The by-products citric pulp and soy hull can substitute the corn grain as energy supplements for rearing of beef heifers.

Palabras llave : soy hull; annual grasses; corn grain; citric pulp; rearing systems.