Seasonal herbage accumulation, plant-part composition and nutritive value of signal grass <i>(Urochloa decumbens)</i> pastures under simulated continuous stocking

Abstract

In order to optimize the regrowth and harvest of signal grass (Urochloa decumbens) cv. Basilisk pastures it is necessary to establish more precise grazing management guidelines. The objective of this study was to evaluate herbage accumulation, plant-part composition and nutritive value of signal grass managed under contrasting levels of steady-state canopy heights. Treatments included 3 canopy height targets, i.e. 10 (S-short), 17.5 (M-medium) and 25 cm (T-tall), in a completely randomized design with 4 replications. Experimental units were 144-m2 plots which were grazed by groups of steers for short periods in an endeavor to keep canopy heights at the 3 desired targets. On average, herbage accumulation rate (HAR) in T pastures was greater than in M and S pastures, including the dry-wet season transition period in spring (September‒November). The S pastures had higher crude protein and lower acid detergent fiber concentrations than M and T pastures, especially in the first half of the calendar year. However, in vitro organic matter digestibility was similar for all treatments (612 g/kg). As S and M pastures had lower HARs than T pastures in the spring, it appears advantageous to maintain the signal grass canopy at ~25 cm in order to ensure quick regrowth with the return of the wet season. However, longer-term studies are needed with recording of animal performance before these initial findings can be promoted widely.

Tree Canopy Management Affects Dynamics of Herbaceous Vegetation and Soil Moisture in Silvopasture Systems Using Arboreal Legumes

“…Although signalgrass shows phenotypic plasticity for moderate shade tolerance [30], in this trial, such mechanisms were not enough to provide the same pasture productivity under denser tree canopy. Similar outcomes were found by [31], who reported decreasing herbage accumulation rate of Urochloa brizantha under intense artificial shading.…”

Endophytic Capacity of Entomopathogenic Fungi in a Pasture Grass and Their Potential to Control the Spittlebug Mahanarva spectabilis (Hemiptera: Cercopidae)

“…Rich Stapf]) [13] Agronomy 2024, 14, 943 2 of 18 monocultivation and high temperatures in the country have led to outbreaks of spittlebugs (Hemiptera: Cercopidae), the main pests in pastures in tropical America [14][15][16][17][18]. Nymphs and adults of this insect pest damage host plants by sucking the sap and injecting toxins that induce phototaxis and reduce photosynthetic rates [19][20][21][22][23], leading to a loss of biomass availability for cattle and reducing the support capacity by 60% on average [15,16,19,[24][25][26].…”

Estratégias de manejo do pastejo associadas a suplementação na mitigação de metano em pastos de capim Mulato II: respostas agronômicas, perfil e cinética da fermentação >i<in vitro>/i< da forragem

“…Critérios de manejo do pastejo por alturas do dossel são consensualmente usados para controlar a estrutura do dossel forrageiro (Giacomini et al, 2009;Vendramini et al, 2014;Braga et al, 2020;. No entanto, o uso de protocolos como "mob stocking" e taxa de lotação variável são indispensáveis para obter refinamentos das metas de manejo por altura do dossel.…”

“…Segundo Parsons et al (1983), também constataram que a ingestão máxima por hectare é alcançada em uma pastagem mantida em um IAF que está substancialmente abaixo do ótimo para a fotossíntese. Extensa quantidade de literatura consolida as informações de manejo do pastejo aqui abordadas, tanto em sistemas sob lotação contínua (Braga et al, 2020;Yasuoka et al, 2021b) quanto à lotação rotativa (Barbosa et al, 2021;Congio et al, 2019;Alvarenga et al, 2020), ou comparando ambos métodos de lotação . Portanto, a utilização técnica integradas do manejo do pastejo, que sejam úteis e confiáveis, como o monitoramento da estrutura do pasto por altura do dossel, associados a estratégias de suplementação, possibilitam juntos mitigar metano e proporcionar flexibilidade no ajuste da taxa de lotação para equalizar a demanda de alimentos em função da disponibilidade de forragem, seja em lotação contínua ou rotativa.…”