For continuously stocked pastures, net forage accumulation is thought to be relatively unaffected across a rather large range of canopy‐based management targets. It is not known whether this is also characteristic of intermittently stocked canopies, and if so, the underlying mechanisms have not been well delineated. We hypothesized that initiation of grazing when canopy heights are shorter than heights corresponding to the critical leaf area index, associated with a moderate intensity of defoliation, do not reduce forage accumulation in pastures under intermittent stocking. Therefore, kikuyugrass (Pennisetum clandestinum Hochst. Ex Chiov) pastures were grazed at four pregrazing heights (10, 15, 20, and 25 cm) with the same proportion of defoliation (50% reduction in pregrazing height; i.e., postgrazing heights of 5, 7.5, 10, and 12.5 cm, respectively) from December 2011 to May 2013. As the canopy height increased, there was an inverse relationship between tiller weight and number; however, heavier tillers presented greater rates of leaf elongation. Pastures grazed at 15 to 25 cm had the same forage accumulation. The same homeostatic mechanisms that keep a constant forage accumulation in different heights when pastures are subjected to continuous stocking also allowed for a similar forage accumulation in pastures under intermittent stocking at different grazing heights.

RESUMO O objetivo deste estudo foi determinar a participação relativa de colmo na estrutura vertical de pastos de capim Aruana e azevém anual submetidos a estratégias de pastejo intermitente por ovinos. Os tratamentos para o capim

-The objective of this study was to evaluate the morphogenetic and structural characteristics of Aruana influenced by the frequency and intensity of grazing adopted, as well as by the seasons, implying that the capacity and speed for the recovery of Aruana grass pastures after grazing depend mainly on the management and edaphoclimatic conditions. The best grazing management for Aruana guineagrass is 95% canopy light interception, i.e., 30 cm pre-grazing height pastures interrupted when reaching 15 cm residue.

-The objective of this study was to assess the accumulation and morphological composition of forage in Aruana Guineagrass (Panicum maximum cv. Aruana) swards subjected to intermittent stocking with sheep. Experimental treatments when grazing was introduced included low (95%) and high (98%) incident light interception and low (10 cm

Two experiments were conducted to assess the effect of pre‐grazing heights and proportions of defoliation on morphological and chemical composition of the grazing layer of two warm‐season perennial grasses of contrasting structures (tall tufted grass—elephant grass, Exp. I; small size stoloniferous grass—kikuyu grass, Exp. II) under intermittent stocking management. The treatments were as follows: Exp. I—factorial arrangement between two pre‐grazing heights (90 and 120 cm) and two proportions of defoliation (removal of 50% or 70% of the initial pre‐grazing heights); Exp. II—four pre‐grazing heights (10, 15, 20 and 25 cm) combined with the same proportion of defoliation (50% of the initial pre‐grazing heights). Forage samples were collected at pre‐grazing heights and clipped into the grazing layer (cutting heights defined by treatments). The following variables were analyzed: (a) forage mass; (b) proportion of leaves, stems, and dead material; (c) crude protein, neutral detergent fiber, and acid detergent fiber contents. In a general way, there were no significant differences in morphological and chemical composition of the grazing layer of treatments with proportions of defoliation of 50%. Although the treatments of 70% (Exp. I) and 10 cm (Exp. II) showed some differences, both targets impaired the grazing process and were considered as unpractical under field situations. It was concluded that forage chemical composition of warm‐season perennial grasses does not change in the upper half of the sward within a range of pre‐grazing heights, provided moderate proportions of defoliation (around 50%) are used.