Elephant grass (pennisetum purpureum schum.) has been grown only in cut-and-carry systems for a long time. However, interest in its grazing management has been increasing because of the selection of short-sized genotypes, which have gained new relevance since 1988 with the registration of ‘mott’ grass. in this sense, tall and short-sized genotypes present important differences in morphology, quality and productivity; although, environmental factors also exert influence on these aspects. This review aimed to approach how the elephant grass size can influence the morphophysiological characteristics, management decisions, and exploitation of this species. the morphophysiological aspects and the elephant grass sizes are important to direct their utilization in the different production systems. The research results from previous decades suggest that the particularities of the tall-sized genotypes, such as great forage accumulation, high organic reserves content, and stem elongation, favor their management in cut-and-carry systems and industrial sectors. Conversely, the short-sized elephant grass genotypes present aspects as higher leaf proportion in the harvested forage, leaf/stem ratio, and tillering. these factors facilitate their exploitation in grazing systems.

The objective of this work was to evaluate the nutritional value of silages from tall-sized and dwarf elephant grass (Pennisetum purpureum) genotypes, intercropped or not with butterfly pea (Clitoria ternatea). The experiment was performed in randomized complete blocks, in a 4x2 factorial arrangement (four genotypes × two cropping systems). The genotypes intercropped or not with butterfly pea were: IRI-381 and Elephant B, tall sized; and Taiwan A-146 2.37 and Mott, dwarf. Forage was harvested 60 days after regrowth. In the silage from Mott grass intercropped with butterfly pea, lower contents of lignin (78.1 g kg-1), neutral detergent fiber (636.0 g kg-1), and neutral detergent insoluble protein (13.15 g kg-1), besides a greater dry matter recovery (873.3 g kg-1), were observed. The silage from Taiwan A-146 2.37 intercropped with the legume showed a greater crude protein content (136.1 g kg-1). In both silages, the ammonia nitrogen contents were quite reduced (26.4 g kg-1). However, greater residual water-soluble carbohydrate contents were observed in the silages from the intercrop (1.85 mg g-1) and from the Mott grass monocrop (1.51 mg g-1). Moreover, there was a lower in vitro dry matter digestibility (676.7 g kg-1) for the silage from the intercrop. Dwarf genotypes increase the nutritional value of elephant grass silage, compared with the tall-sized ones. Intercropping with butterfly pea improves silage fermentation characteristics, despite reducing its digestibility. Therefore, the ensilage of dwarf Mott elephant grass intercropped with butterfly pea shows more promising results.

The objective of this study was to describe and explain the effect of adding corn meal (CM) on losses, fermentation characteristics and nutritional value of silages from two elephant grass [Cenchrus purpureus (Schumach.) Morrone] genotypes (Taiwan A-146 2.37 and IRI-381) mixed with butterfly pea (Clitoria ternatea L.) legume. The forage was harvested at 75 days of regrowth from elephant grass plots intercropped with butterfly pea legume and ensiled with or without CM at 5% of dry matter (DM) content. Greater gas losses (12 g/kg) and pH (4.2) were observed in the Taiwan A-146 2.37 + butterfly pea silages. The greatest crude protein content was observed in the ‘Taiwan A-146 2.37’ + butterfly pea silage added with CM (116 g/kg). Silages with additive and those containing IRI-381 had a greater acid detergent fibre content (367 and 366 g/kg, respectively). CM increased the silage DM (221 g/kg), remaining water-soluble carbohydrates contents (26 g/kg) and in vitro digestibility of DM. The aerobic stability was maintained until 45 h after opening the silos. All silages presented a good fermentative profile and were not affected by the relatively large proportion of butterfly pea (>34%) in the ensiled mass as indicated by the reduced contents of butyric acid and ammonia nitrogen. CM reduces total losses, increases DM recovery and improves the nutritional value of silages from mixed elephant grass–butterfly pea legume.

The aim of this study was to evaluate nutritional value, fermentation losses, and aerobic stability of elephant grass silage (Pennisetum purpureum Schum.) treated with exogenous fibrolytic enzymes. The experiment was conducted in a completely randomized design with four replicates (experimental silos) and five levels of fibrolytic enzymes (0, 1.5, 3.0, 4.5 and 6.0%). For this, the elephant grass was ensiled at 70 days of age in plastic buckets with 20L capacity. Silos were opened 60 days after sealing. Analyses were made for chemical composition, in vitro dry matter digestibility (IVDMD), effluent losses (EL), gas losses (GL) and dry matter recovery (DMR), as well as the aerobic stability of the silage. Data were analyzed with PROC REG of SAS® University, at 5% probability. There was an increase in IVDMD content (p < 0.0001) and reduction in NDF and ADF contents (p < 0.0001) according to enzyme levels. These results were related to the increase in the degradation of fiber fractions. There were higher EL (p = 0.0062) as a function of enzyme levels and aerobic deterioration after silo opening, at all levels tested. Thus, it can be concluded that the exogenous fibrolytic enzymes change the chemical composition of elephant grass silage, and increase its digestibility and nutritional value. Moreover, when used alone as an additive, fibrolytic enzymes are not able to recover all dry matter of this silage (with effluent and gas losses), and are not able to maintain aerobic stability in the first hours after opening the silos.

Context: Introducing legumes into grass-based forage systems may increase herbage nutritive value while reducing the need for inorganic nitrogen fertilisation. Grass–legume intercrops may also enhance herbage yield stability. Aim: We evaluated agronomic and nutritional traits of elephant grass (Cenchrus purpureus Schum.) genotypes grown as monocrops and mixed with butterfly pea (Clitoria ternatea L.). Methods: Elephant grass genotypes, two tall (Elephant B and IRI-381) and two dwarf (Mott and Taiwan A-146 2.37), were grown as monocultures or intercropped with butterfly pea in a 2-year trial. Herbage accumulation, yield stability, botanical composition and chemical/bromatological variables were evaluated. Key results: Herbage accumulation was highest (P < 0.001) in Elephant B under monocropping (21.9 t/ha.year); however, this treatment revealed the lowest yield stability over harvest times (σi2 5.59). All intercrops were more stable than grass monocrops (mean σi2 0.66 vs 2.55). Higher (P < 0.001) concentrations of herbage crude protein were found in intercrops than monocrops (mean 113 vs 90 g/kg). Intercrop herbage lignin contents (mean 57 g/kg) and protein fraction C (mean 61 g/kg) were higher than those in monocrops. Dwarf Mott had higher (P = 0.001) digestible dry matter concentration than dwarf Taiwan (755 vs 745 g/kg). Conclusions: Dwarf Mott genotype has outstanding nutritive value because of its higher leaf:stem ratio. Butterfly pea legume added to elephant grass crop in cut-and-carry systems improves herbage yield stability by reducing seasonal effects. Implications: Intercropping butterfly pea in grass-based systems enhances yield stability, allowing herbage harvest with good nutritive value.

The objective of this work was to evaluate the effects of the inclusion of pelleted citrus pulp and microbial inoculant on the fermentation characteristics, carbohydrate and protein fractionation, and total digestible nutrient contents of 'Massai' grass (Megathyrsus maximus × Megathyrsus infestus) silage. The experimental design was completely randomized, in a 2×4 factorial arrangement (application or not of inoculant × 0, 10, 20, and 30% citrus pulp) with five replicates. There was an increase in dry matter recovery as affected by citrus pulp levels. The values obtained for pH and ammonia nitrogen indicated an adequate fermentation process. Under increasing citrus pulp levels, there was a reduction in neutral detergent fiber and an increase in nonfibrous carbohydrate contents and in protein linked to fiber. Total digestible nutrient content reaches a peak of 513.1 g kg1 with the inclusion of 12.50% citrus pulp. The microbial inoculant, when isolated, does not influence carbohydrate and protein profiles. Inclusions between 10 and 20% citrus pulp are able to maintain adequate fermentative parameters and improve the digestible nutrient profile, with an adequate dry matter recovery.