Biomass flow in Tifton-85 bermudagrass canopy subjected to different management strategies under rotational grazing with dairy goats

Abstract

-Biomass flow characteristics and forage accumulation were evaluated in Bermudagrass (Tifton 85) pasture managed under intermittent stocking with different management strategies. The management levels utilized were conventional (10 cm residual height and unfertilized), light (20 cm residual height and unfertilized), moderate (20 cm residual height with fertilization of 300 kg N/ha.year) and intensive (10 cm residual height with fertilization of 600 kg N/ha.year). A randomized design was used with repeated measurements over time, in two periods of the year, with four replicates. There was significant effect of management × period of the year on the leaf elongation rate (LER). The management levels under fertilization (0.59 and 0.60 cm/tiller.day for the intensive and moderate management, respectively) and the rainy season (0.49 cm/tiller.day) showed the greatest stem elongation rate. Leaf senescence rate (LSR) before and after and total LSR were modified by the management × period of the year interaction. The intensive management, with 0.38 leaves/tiller. day, as well as the dry period, with 0.27 leaves/tiller.day, showed higher leaf appearance rate. The lowest phyllochron was observed in intensive management and dry periods, as well as an interaction with the management of the same periods of the year. There was management × period of year interaction effect on leaf lifespan; the highest value was found under conventional management and dry period. Both production and forage accumulation rates were higher in the intensive and moderate management levels and dry season, and there was interaction of the intensive management system with the seasons. Managing pastures under moderate and intensive rotational stocking, which occurred mainly in the rainy and dry seasons, respectively, maximizes the flow of tissues and consequently production and accumulation of forage.

Effects of leaf and stem maturation on nutritional value in Megathyrsus maximus

“…Stem elongation exerts a strong translocation of carbon to the supporting structures of plants which, in forage grasses such as M. maximus, reduces leaf/stem ratio and, consequently, promotes lower forage quality. 52 In our work, a higher value of DW was associated with a rapid decline in stem digestibility, and genotypes with faster stem elongation generally show higher DW production which agrees with the report of Batistoti et al 13 Moreover, strong positive correlations between sclerenchyma, vascular tissue, and ADL were also observed, because the thickness of the cell wall is highly lignified. The internal organization and proportion of the system tissues and cell types may influence the intake and the proportion of polysaccharides suitable for microbial attack within the rumen.…”

“…In the stems, the PCA showed that the value of DW was highly associated with the variables ADL, vascular tissue, and NDF. Stem elongation exerts a strong translocation of carbon to the supporting structures of plants which, in forage grasses such as M. maximus , reduces leaf/stem ratio and, consequently, promotes lower forage quality 52 . In our work, a higher value of DW was associated with a rapid decline in stem digestibility, and genotypes with faster stem elongation generally show higher DW production which agrees with the report of Batistoti et al 13 .…”

Dissimilarity between Andropogon lateralis ecotypes under different defoliation frequencies and heights

“…LDM showed a significant correlation with the variables NVT, NTT, LS and SDM, with correlation coefficients of r = 0.57 (P≤0.01), 0.52 (P≤0.01), 0.39 (P≤0.01) and 0.34 (P≤0.01), respectively (Figure 1). For each leaf blade formed there is a new phytomer and buds that will be responsible for the origin of new tillers when they receive light stimuli (CUTRIM et al, 2013). Thus, the median correlation observed between LDM, NVT and NTT, may infer that the defoliation management practices tested favored the renewal of plant tissues.…”

Biomass flows and defoliation pattern of ryegrass grazed by supplemented heifers

“…has been extensively studied due to its importance for livestock production systems in southern Brazil (CONFORTIN et al, 2010(CONFORTIN et al, , 2013BANDINELLI, 2005), and studies on biomass flows have been performed for both tropical (CUTRIM JUNIOR et al, 2013;LOPES et al, 2013) and temperate species such as ryegrass (CAUDURO et al, 2007;CONFORTIN et al, 2009;PONTES et al, 2004). However, no studies have been published on the flows of leaf biomass at high stocking rates as a result of intake of different supplements by cattle.…”