Productivity and nutritive value of mixed pastures with different legume species/Produtividade e valor nutritivo de pastos consorciados com diferentes especies de leguminosas

The objective of this research was to evaluate the productivity and nutritive value of two pasture-based systems (PS) with elephant grass (EG) + ryegrass (RG) + white clover (WC') + spontaneous growing species (SGS), for PS1; and EG + RG + forage peanut (FP) + SGS, for PS2. EG was established in rows spaced by four meters. Ryegrass was seeding in the space between rows during cool-season and development of SGS was permitted in the warm-season. Holstein cows under rotational grazing were used in the evaluation. The initial forage mass (IFM), the botanical composition and the structural components were evaluated. Samples from hand-plucking method were collected to analyze neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD). The experimental design used was completely randomized with two treatments, two repetitions in complete split-plot time. The mean values of initial forage mass and stocking rate were similar among PS. Superior results were found for mean of CP in PS2. The use of ryegrass, legumes and spontaneous growing species mixed to EG allow the forage mass to be uniform during the grazing pastures. Key words: Arachis pintoi, chemical composition, forage mass, Lolium multiflorum, Pennisetum purpureum, Trifolium repens. O objetivo desta pesquisa foi avaliar a produtividade e o valor nutritivo de dois sistemas forrageiros (SF) constituidos por capim elefante (CE), azevem (AZ), trevo branco (TB) e especies de crescimento espontaneo (ECE), como SF1; e CE + AZ + amendoim forrageiro (AF) + ECE, como SF2. O CE foi estabelecido em linhas espacadas a cada quatro metros. Entre elas, foi estabelecido azevem, durante o periodo hibernal, permitindo-se o desenvolvimento de ECE no periodo estival. Para avaliacao, foram utilizadas vacas da raca Holandesa e o metodo de pastejo foi o rotacionado. Avaliaram-se a massa de forragem inicial (MFI) e a composicao botanica e estrutural dos pastos. Para as estimativas de valor nutritivo, foram feitas amostragens simulando o pastejo e analisados a fibra em detergente neutro (FDN), fibra em detergente acido (FDA), proteina bruta (PB), digestibilidade in vitro da materia seca (DIVMS) e digestibilidade in vitro da materia organica (DIVMO). O delineamento experimental foi o inteiramente casualizado com dois tratamentos e duas repeticoes, em parcelas subdivididas no tempo. Os valores medios de massa de forragem inic