Abstract

JIMENEZ GUILLEN, Régulo et al. Biomass composition of a mixed pasture signal grass-clitoria grazed at different forage allowance. Rev. mex. de cienc. pecuarias [online]. 2013, vol.4, n.2, pp.185-199. ISSN 2448-6698.

Grass-legume association has been recognized for improving animal response but is necessary to better understand components performance under different prairie management practices. The main purpose was to define produced biomass and botanical composition within a clitoria and Signal grass associated prairie for dry tropic conditions, using different levels of forage allowances: 2.5, 4.0, 5.5, and 7.0 kg DM 100 kg^-1 LW d^-1. Experimental unit consisted of 400 m² plots. Post-weaned calves were used as defoliators under a rotational grazing system, using three days for grazing and 42 d of rest. Four grazing periods were evaluated during the rainy season. The response variables estimated were: biomass and its components: Signal grass, clitoria, other species, leaf, stem, pod, live matter, and death matter. The treatments were distributed in camp through a randomly blocked design using four repetitions. Data was analyzed by GLM procedure of SAS program. Heights of grass and legume were modified by forage allowances. Grazing using a 2.5 kg DM by 100 kg^-1 LW d^-1 of forage assignation produced the lowest forage biomass (P<0.05) pre and post grazing. Signal grass and his components were sensible to forage allowances but not in clitoria. Forage assignation of 4.0 kg DM by 100 kg^-1 LW d^-1 may be the best option for the long term persistence of this association, preserve their components and produce bigger amounts of leaf and live matter of Signal grass at forage assignations of 5.5 and 7.0 kg DM by 100 kg^-1 LW d^-1.

Keywords : Brachiaria decumbens; clitoria ternatea; Bovines grazing; Forage allowances; Biomass composition.