Grazing intensity affects forage accumulation and persistence of Marandu palisadegrass in the Brazilian savannah

Abstract

This 3‐year study evaluated the effects of grazing intensity on herbage and steer responses in continuously stocked Brachiaria brizantha cv. Marandu pasture in the Brazilian savanna. Treatments consisted of three grazing intensity levels, characterized by canopy heights of 15, 30 and 45 cm, measured twice per week. Responses variables included tiller population density (TPD), herbage accumulation rate (HAR) and body weight gain per area (WGA). A decline in TPD (1,237 vs. 767 tillers/m2) was observed from the first to the third grazing years, which influenced the HAR from the first to the third years (90.1 vs. 52.4 kg ha−1 day−1). A marked decline in body WGA (541 vs. 276 kg ha−1 year−1) was observed along the three years in pastures managed at a height of 15 cm, indicating that this is an unstable condition for Marandu palisadegrass pasture. HAR was similar for pastures managed at 30 or 45 cm and was relatively stable during the experimental period, averaging 91.8 and 99.1 kg ha−1 day−1 respectively. Body WGA was similar and constant throughout the experimental period for pastures managed at 30 (596 kg ha−1 year−1) and 45 cm (566 kg ha−1 year−1). Maintaining continuously stocked Marandu palisadegrass pastures at a 15 cm canopy height should be avoided due to long‐term decreases in plant persistence and animal body WGA, particularly when soil P is below critical levels at pasture establishment and during pasture utilization.

Herbage responses of Tamani and Quênia guineagrasses to grazing intensity

“…The similar and high leaf proportions of Quênia and Tamani resulted in minor differences in NDF and ADF concentrations, which were mostly due to the grazing intensity (Euclides et al., 2019) or season effects (Carvalho, Pereira, Hungria, Camargo, & Da Silva, 2019; Euclides et al., 2018). Crude protein concentrations were affected only by season, with the least values in the last two seasons (spring 2016 and summer 2017) attributable to the increased stem and dead material proportions in the pre‐grazing HM.…”

Unravelling the relationship between a seasonal environment and the dynamics of forage growth in grazed swards

“…Therefore, it seems that there are no reasons to maintain greater LAI during winter–early spring since stressful factors (usually present in those seasons in the tropics) lead plants to deviate photoassimilates to organic reserve formation. However, caution is necessary since grazing heights lower than 15 cm seems to be detrimental to marandu palisadegrass persistence (Euclides et al, 2019).…”

Different Grass Availabilities of Tropical Pasture on Performances and Carcasses of Lambs

“…Herbage dry matter was measured every 28 days by the total sampling method, which consisted of harvesting six samples per paddock near the soil level (Euclides et al, 2019). The material was collected from within 0.5 × 0.5 m metal frames that were cast over random points representative of each paddock.…”

“…(Syn. Brachiaria) is the most widely used pasture in the Brazilian cerrado biome regions by virtue of its hardiness and little need for fertilizer (Euclides et al, 2019). In those regions, productions of animals are mostly finished on pasture.…”