Grasses, Volume 4, Issue 2 (June 2025) – 5 articles

Erratic rainfall and extended dry periods challenge forage production and livestock feed sustainability in dryland agriculture regions. This study investigated the effects of planting dates and genotype selection on the nutritive value and in-vitro dry matter degradability (IVDMD) of fodder radish genotypes in Midlands of KwaZulu-Natal, South Africa. The experiment followed a completely randomised design with three fodder radish genotypes (Endurance, Line 2, and Nooitgedacht) and five planting dates (December, January, February, March and May). After three months of growth in each planting date, crops were harvested, prepared and analysed for various nutritional parameters including crude protein, fibre content, and IVDMD. Results revealed that December had the highest crude protein (28–31%) across genotypes, while March plantings optimised total non-structural carbohydrates (13.31%) and metabolisable energy (6.64 MJ/kg). The Nooitgedacht genotype demonstrated improved performance, achieving higher IVDMD of 85.54% for leaves in December plantings and 77.51% for tubers in February plantings. Significant interactions between planting dates and genotypes were observed for ash, crude protein, and cellulose in leaves. In conclusion, these findings highlight the crucial role of planting date selection and genotype choice in optimising fodder radish production under dryland conditions, offering valuable insights for enhancing livestock productivity and supporting sustainable rural livelihoods. Full article

Forage legumes, besides their use as ruminant feed supplements, contribute to other agricultural, forestry and natural ecosystems’ sustainability around the world. Our objective in this summary is to emphasize that versatility in the face of biotic, abiotic and socio-economic variability is among the most important traits that forage legumes contribute to sustaining human populations in those diverse ecosystems. Forage legumes could contribute even more to agroecosystems if we 1. consider ecosystem services as well as food, feed and fuel production; 2. more fully exploit what we already know about forage legumes’ multiple uses; and 3. focus greater attention and energy exploring and expanding versatility in currently used and novel versatile species. To draw attention to the importance of this versatility to sustainable grasslands, here we review multiple legumes’ roles as forage, bioenergy, pulses (legume seeds for human consumption), pharmaceuticals and cover crops as well as environmental services, in particular soil health, C sequestration and non-industrial organic N. The major points we single out as distinguishing sustainable versatile forage legumes include (1) multiple uses; (2) adaptation to a wide range of edaphoclimatic conditions; (3) flexible economic contributions; and (4) how genomics can harness greater legume versatility. We predict that, because of this versatility, forage legumes will become ever more important as climates change and human pressures on sustainable agro-environments intensify. Full article

The pasture–animal interface of warm-season perennial grass–legume mixed pastures has never been investigated in forage-based equine systems. Therefore, this 2-year study investigated the herbage and animal responses under 84-day continuous stocking in mixed pastures of rhizoma peanut (RP, Arachis glabrata Benth) and bahiagrass (BG, Paspalum notatum Flüggé) with 30 kg nitrogen (N) ha⁻¹ (BG-RP) compared to BG pastures fertilized with 120 kg N ha⁻¹ (BG-N₁₂₀) and no N (BG-N₀). Measurements were taken every 14 days, except for intake and in vivo digestibility, which were measured every 28 days. BG-N₁₂₀ had the highest stocking rate (p = 0.01; 3.7 AU ha⁻¹) in 2019, while BG-N₀ had the lowest (p = 0.01; 2.6 AU ha⁻¹) in 2020. Crude protein and digestible energy were greatest (p < 0.05) for BG-N₁₂₀ and BG-RP in some of the evaluation days in 2019 but similar across pastures in 2020. Crude protein digestibility was greatest (p < 0.05) for BG-RP in the late season. Intake was less (p = 0.03) for horses grazing BG-RP (3.2%BW) compared to BG-N₀ (5.0%BW). Nonetheless, no differences (p > 0.05) were observed among pastures for body measurements. The results indicate that BG-RP pastures can improve forage nutritive value and maintain horse body condition while maintaining similar stocking rate to monoculture bahiagrass with high N fertilizer rates. Full article

Global beef demand will rise by 40 million tons in 30 years, increasing methane (CH₄) emissions. Pigweed (Amaranthus spinosus), an invasive weed abundant in southeastern U.S. pastures, may mitigate CH₄. Yet, its potential as a feed additive remains unexplored. The aim of this study was to evaluate the influence of pigweed and its extracts on ruminal fermentation and CH₄ production. For Exp 1, ruminal fluid from three American Aberdeen steers was incubated with 0, 2.5%, 5%, or 10% of diet dry matter (DM) of roots, stems, leaves, seeds, or the whole pigweed plant (WHO). In Exp 2, extracts from the leaves and WHO were incubated under the same conditions. For the first experiment, 2.5% of the roots, 5% of the leaves, and 10% of the WHO decreased acetate and butyrate concentrations (p < 0.01). In contrast, the WHO, leaves, and seeds at 2.5% of DM increased propionate concentration (p = 0.05). Increasing levels of WHO, leaves, and seeds quadratically reduced CH₄ (p < 0.001). The addition of 2.5 and 5% of leaves and WHO reduced in vitro CH4 production per gr of organic matter fermented (p < 0.01). In Exp 2, based on their CH₄ mitigation, the leaves and WHO were extracted, and their phenol (3.2 and 1.1 mg/g of DM, respectively) and flavonoid (19.7 and 1.9 mg/g of DM, respectively) contents were determined. Extracts from WHO (2.5%) decreased acetate and CH₄ (p < 0.05), while 5% inclusion decreased gas production and increased ruminal pH (p < 0.03). Leaf extracts (2.5%) increased propionate and reduced acetate: propionate (p < 0.05). The leaves and WHO extracts did not affect IVOMD at either inclusion level (p > 0.4). Extracts at 5% from WHO were more effective than that from leaves in reducing CH₄ (27% vs. 4%). The evidence suggests that the inclusion of 2.5 to 5% of WHO extracts shifts ruminal fermentation towards propionate-producing impairing methanogenesis, representing a sustainable strategy to mitigate CH₄. This hypothesis must be further assessed under in vivo supplementation of the extracts to beef cattle. Full article

The aim was to evaluate the productivity, agronomic characteristics, and chemical and mineral composition of pearl millet genotypes irrigated with brackish water under the application of agricultural gypsum in two cuts. The experiment was a randomized block design in a 4 (gypsum levels—0, 2, 4, and 8 ton ha⁻¹ applied on the surface) × 3 (pearl millet genotypes—ADR 300, BRS 1501, and IPA BULK 1BF) factorial arrangement, with three replications, irrigated with high brackish water and low sodium. Agricultural gypsum had no significant effect on productivity, agronomic characteristics, and chemical and mineral composition (p > 0.05). In the first cut, higher mean values were found for the percentage of panicle, crude protein, ether extract, in vitro dry matter digestibility, calcium, sulfur, and manganese (p < 0.05). For the second cut, higher results were observed for green matter productivity, dry matter productivity, water use efficiency, stem percentage, stem diameter, average leaf size, panicle size, acid detergent fiber, lignin, cellulose, total carbohydrates, potassium, and copper (p < 0.05). IPA Bulk 1 BF showed a larger panicle size in both cuts (p < 0.05). The evaluated pearl millet genotypes showed desirable agronomic characteristics and tolerance to irrigation with brackish water regardless of gypsum application, thus they are indicated for cultivation in the semi-arid regions. Full article