Forage value of vegetative leaf and stem biomass fractions of selected grasses indigenous to African rangelands

Abstract

Context. Rangeland grasses native to Africa constitute the main diet for free-ranging livestock and wild herbivores. Leaf:stem ratio is a key characteristic used for assessing quality of forages. However, studies to determine the allocation of biomass to leaves and stems as well as chemical components and nutritive value, especially of grasses in African rangelands, are rare.Aim. This study was conducted to establish biomass allocation and chemical and mineral components in leaf and stem fractions of three grasses, Eragrostis superba, Enteropogon macrostachyus and Cenchrus ciliaris, all indigenous to African rangelands.Methods. Plant height, plant densities, plant tiller densities and biomass yields were estimated at the elongation stage, before inflorescence. Chemical and mineral components were determined from biomass harvested at the vegetative phase for all three grass species. Dry matter, ash content, organic matter, crude protein, neutral detergent fibre, acid detergent fibre, acid detergent lignin, and calcium, phosphorus and potassium contents were determined.Key results. Enteropogon macrostachyus displayed significantly greater plant and tiller densities and plant height than the other two species. Leaf and stem biomass fractions varied significantly (P < 0.05) among grasses. Leaf:stem ratio of E. superba was double that of E. macrostachyus and C. ciliaris. Crude protein and organic matter yields and net energy for lactation were highest (P < 0.05) in E. superba leaf biomass, as was Ca content.Conclusions. Eragrostis superba demonstrated greater potential as a forage species for ruminant animal production than E. macrostachyus and C. ciliaris.Implications. Eragrostis superba is a key forage species that warrants promotion in pasture establishment programs in its native environments.

Productivity and Feed Quality Performance of Napier Grass (Cenchrus purpureus) Genotypes Growing under Different Soil Moisture Levels

“…Generally, the leaf is more digestible, higher in CP and lower in fiber components than the stems [ 39 ]. Such differences in feed nutrition between the leaf and the stem might be attributed to the photosynthesis/metabolic role of leaves and the structural role of stems [ 40 ]. Consequently, improving feed quality relies, at least partially, on increasing the proportion of the leaf when harvested.…”

Effects of leaf and stem maturation on nutritional value in Megathyrsus maximus

“…In our work, however, all genotypes showed higher values of DMD in leaf blades than stems for the three cuts evaluated. Mganga et al 49 . found similar results in Eragrostis superba , Enteropogon macrostachyus , and Cenchrus ciliaris .…”

“…In our work, however, all genotypes showed higher values of DMD in leaf blades than stems for the three cuts evaluated. Mganga et al 49 found similar results in Eragrostis superba, Enteropogon macrostachyus, and Cenchrus ciliaris. However, it is noteworthy that Mutale and Vencedor genotypes had higher digestibility values in the earlier stages for stems, but not at the level of leaf blades.…”

Forage production, morphogenetic and structural components, and nutritional value of tropical grasses in the semiarid condition

“…Urochloa humidicola cv. Llanero showed the highest leaf:stem ratio, which influences the quality of the forage and improves grazing efficiency when above 1 (Grev et al, 2020;Mganga et al, 2021). Among the Megathyrsus cultivars evaluated, the higher stem weight seen in cv.…”