Chemical composition and in vitro total gas and methane production of forage species from the Mid Rift Valley grasslands of Ethiopia

Abstract

There is increasing interest in sustainable land use in the tropics to optimize animal production while also reducing methane (CH4) emissions, but information on nutritive value and CH4‐emission potential of tropical forage species is limited. Samples of 24 grasses and five other forages were collected during the main rainy season on randomly positioned quadrats in semi‐arid grassland in the Mid Rift Valley of Ethiopia. Samples were pooled by species, analysed for chemical composition and incubated with rumen fluid to determine total gas and CH4‐emission potentials using a fully automated in vitro gas production apparatus. Organic matter digestibility (OMD) and metabolizable energy (ME) contents were calculated from chemical composition and gas production data. Large variability was observed among forages for all nutritional variables considered. The grasses Eleusine multiflora, Pennisetum stramineum, Dactyloctenium aegyptium, Eragrostis aspera, Cenchrus ciliaris and Eragrostis cilianensis showed relatively high OMD (68–72%) and ME values (9·1–10·2 MJ kg−1 dry matter). Melinis repens, E. multiflora and the non‐legume forb Zaleya pentandra showed relatively low CH4 to total gas ratios; these species may have potential for use in low CH4‐emission forage diets. Acacia tortilis fruits had high content of crude protein and moderate ME values, and may be an ideal feed supplement for the grazing ruminant. Sodium content was below the recommended level for ruminants in all the forage species. Overall, the pasture stand during the main growing season was evaluated as having moderate nutritional quality.

Variations in water relations, stomatal characteristics, and plant growth between quinoa and pea under salt-stress conditions

“…Preliminary investigations also show that the range grasses can be deficient in some essential minerals such as Na and Cu (Khan et al, 2009b). Recent research shows that information on chemical composition, digestibility and methane emission potential of pasture species is needed for the sustainable and knowledgebased improvement of grazing livestock production (Bezabih et al, 2014b).…”

Methane Emissions from Ruminant Livestock in Ethiopia: Promising Forage Species to Reduce CH4 Emissions

“…All the studied forages, except C. cajan, had OMD values above 70%, which suggests that these forages have high nutritional value for ruminants. Meissner et al (2000), cited in Bezabih et al [48] reported that forages having an OMD of 70% or more are considered to be of high quality. In line with this, Evitayani et al [47] reported that the OMD of forages above 50% is a good indicator of their potential to supply ME.…”

The Occurrence and Toxicity of Indospicine to Grazing Animals

“…I. hendecaphylla and I spicata are often confused in literature, and it was only recently established that the species of Indigofera found in Hawaii was I. spicata [22]. Even though their toxicity has been recognized for more than 70 years [6], these species are still utilized as forage in their native range [23]. I. linnaei has a less extensive global distribution and is native across northern Australia, India, Indochina through Malesia, Melanesia to New Guinea [24].…”