Nutritional Value of Marandú Palisade Grass According to Increasing Coexistence Periods with Weeds

Abstract

This research aimed at evaluating the effect of increasing coexistence periods with weeds on the nutritional components of the forage grass Brachiaria brizantha cv. Marandú under pasture renewal conditions. The experiment was arranged in randomized blocks with four replications, and treatments were represented by eight coexistence periods, namely: 0, 15, 30, 45, 60, 75, 90 and 120 days after seedling emergence. A phytosociologic evaluation was performed on the weed community at the end of the coexistence periods; later, weeds were eliminated by an herbicide formulated with aminopyralid+2,4-D (40+320 g L-1) at 2.5 L ha-1, applied in post-emergence. The fodder plants were evaluated at the end of the experimental period as for leaf-stem ratio, volumetric density of green leaf, volumetric density of total dry matter and main nutritional components, including: crude protein, neutral detergent fiber, ether extract, organic matter and mineral matter, and from this, the total carbohydrate content was calculated. The presence of weeds altered the pasture structure, since it affected negatively the leaf/stem ratio and the volumetric leaf density of B. brizantha. The coexistence also reduced the nutritional components of B. brizantha and determined that control measures should be adopted before reaching 30 days of coexistence between fodder plants and weeds.

Potential of methane and carbon dioxide in vitro production by Urochloa hybrid subjected to periods of coexistence with weeds

“…These results corroborate a phytosociological study carried out by Marchi et al (2017) and Bellé et al (2018) on a pasture of Urochloa brizantha cv. Marandú.…”

“…The main problem caused by weeds is the direct competition for space, light, water, and nutrients, causing a reduction of the physiological reserves of forages (SANTOS et al, 2011). When competing for growth factors, weeds can also provide decreases in the nutritional value and pasture support capacity, provide an increase in the time of pasture formation and recovery, cause injury and/or intoxication to animals, and compromise the aesthetics of the property (MARCHI et al, 2017;BELLÉ et al, 2018;MARCHI et al, 2019).…”

“…Considering that gas production varies according to the quantity and quality of the food ingested by the animal and that weeds can influence these two characteristics of tropical forages (MARCHI et al, 2017;BELLÉ et al, 2018;LOURENÇO et al, 2019), this research aimed to study the interference relationships of weeds on productive components, nutritional quality, energy potential, and production potential of GHG by the Convert HD364 grass under pasture renovation conditions.…”

Potential of Greenhouse Gas Production by Guinea Grass Subjected to Weed Competition

“…Upon competing for growth factors, weeds may also reduce the grasses' capacity to support pastures, increase pasture formation and recovery time, cause injury and/or intoxication, and compromise the aesthetics of the property (Carvalho et al, 2016;Bellé et al, 2018;Marchi et al, 2019). Thus, the extractive aspects of the system of exploitation associated with the consequences of the presence of weeds compel animals to eat foods with a low nutritional value, which provides lower feed efficiency, lower animal performance and, consequently, higher methane emission (CH 4 ) per kilogram of meat produced (De Zen et al, 2008).…”

Los pastos estrella africana, kikuyo y “rye grass” en Cartago, Costa Rica: biomasa, composición botánica y nutrientes

“…Por último, en el pasto Ryegras se resume una producción promedio de 4 110kg MS/ha/ciclo y valores de MS, PC, FDN, FDA, EE y cenizas de 15,92; 25,21; 49,76; 25,57; 2,61 y 9,96% respectivamente (Villalobos, 2006). Sumado a este ejercicio de caracterizar la productividad del cultivo, valorar su composición botánica y su dinámica según el pastoreo, es una señal de sostenibilidad de la pastura, debido a que las coberturas secundarias, compiten por espacio, radiación, nutrimentos de la solución del suelo con el cultivo principal (Galon et al, 2018), presentan alelopatías que reducen la viabilidad de la pastura (Yuan et al, 2018), albergan poblaciones de nematodos que afectan las raíces del cultivo principal (Núñez, 2017); además de reducir la disponibilidad (Harker, Baron, Chanasyk, Naeth, & Stevenson, 2000) y la calidad de la materia seca comestible para los semovientes (Belle, Marchi, Martins, Sousa, & Pinheiro, 2018) . En el caso de la composición botánica, los estudios en pasto estrella, kikuyo y ryegrass, describen además de la cobertura principal, la presencia de otras gramíneas, arvenses y material senescente.…”