03508nam a2200193 a 450000100080000000500110000800800410001910000170006024501360007726001730021352027730038665000250315965000260318470000210321070000190323170000210325070000230327170000200329420662702020-10-04       2016    bl uuuu     u01u1 u    #d1 aCRESTANI, S.  aChemical composition of leaves of the Piatã grass under shaded condition and submitted to deferred grazing.h[electronic resource]  aIn: REUNIÃO ANUAL DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 53., 2016, Gramado. Produção animal para as novas gerações: anais. Gramado: SBZ, 2016. Não paginado.c2016  aThe integrated production systems aim the agriculture sustainability. In the same way, deferment grazing is a technique that helps the producer with forage supply in moments of deficit of feed without increasing production costs. With knowledge, the integration of systems and the deferred grazing can be used together to improve the forage planning. The objective of this experiment was to evaluate the shade effects on chemical composition of the leaf blade of Piatã brachiaria grass (Brachiaria brizantha cv. Piatã) submitted to deferred grazing. The experiment was carried out at Embrapa Agrossilvipastoril, Sinop, MT, Brazil (11º51'43'' S, 55º35'27'' W, 384 m) from February to June 2014. A crop-livestock-forest integration area was divided into two light regimes: Piatã cultivated in the absence of trees (full natural light; FL); and Piatã cultivated under shade produced by four triple rows of trees (Eucaliptus H13 clone, 650 trees ha-1) with pasture between the rows (S2). Treatments correspond to combinations between: light regimes (FL and S2), two beginnings of rest period (R1 ? February 26, R2 ? March 28) and two grazing dates (G1 ? May 16, G2 ? June 16). These were applied to experimental units (15 x 4 m plots) in a 2x2x2 factorial arrangement, with four replications. Total rainfall and duration of deferment corresponded to 223 mm and 79 days (R1G1), 257 mm and 110 days (R1G2), 126 mm and 49 days (R2G1) and 150 mm and 80 days (R2G2), respectively. At the beginning of rest period (R1 and R2), plots were mowed at 10 cm and at the end of the deferment period (G1 and G2) four samples harvested (0.25 m2). These samples were mixed and a subsample was separated in leaf blade and other materials. The leaves were analyzed by Near Infrared Reflectance Spectroscopy (NIRS). Statistical analysis was performed using the PROC Mixed of SAS at a 5% probability level. Light regime S2 showed 40% of light transmittance of FL (100%). Crude protein was higher for S2, R2 and G1 (134, 123 and 127 g DM kg-1) compared to FL, R1 and G2 (105, 116 and 112 g DM kg-1, respectively). Acid detergent fiber and neutral detergent fiber was higher for FL (347 and 692 g DM kg-1) than S2 (331 and 663 g DM kg-1) and for R1 (341 and 681 g DM kg-1) than R2 (336 and 674 g DM kg-1). The organic matter digestibility was higher for S2 than FL (639 and 601 g DM kg-1) and for G1 than G2 (636 and 604 g DM kg-1). The effects of the deferment period on chemical composition of the leaves were expressive for Piatã submitted to shade and full natural light, however, the shaded pasture maintained more efficiently the forage chemical composition of the leaves. So, silvipastoral system is a technique that can be used to prolong the utilization of the deferred pasture.  aChemical composition  aSilvopastoral systems1 aCABALLERO, J. D.1 aGEREMIA, E. V.1 aMONTAGNER, D. B.1 aMONTEIRO, R. A. C.1 aSILVA, S. C. da