Grass size and butterfly pea inclusion modify the nutritional value of elephant grass silage

Abstract

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.

Adding corn meal into mixed elephant grass–butterfly pea legume silages improves nutritive value and dry matter recovery

“…Lemos et al . (2021), evaluating silages of IRI-381 and Taiwan A-146 2.37 elephant grass genotypes intercropped with butterfly pea, did not report high pH values (3.97). Santos et al .…”

“…Lemos et al . (2021) reported values of 1.85 g/kg DM in elephant grass silages mixed with butterfly pea, while elephant grass silages without the legume presented 1.34 g/kg DM. Santos et al .…”

“…The elephant grass genotype IRI-381 is considered a tall type, and Taiwan A-146 2.37 is a dwarf type and both were intercropped by butterfly pea, an adapted forage legume. These two genotypes were chosen based on results obtained from a previous study conducted in the same area (Lemos et al ., 2021).…”

“…Irregular rainfall distribution and unfavourable conditions for forage production require alternatives to support animal production (Furtado et al ., 2019; Lemos et al ., 2021). Ensiling is one of the most used forage conservation methods (Santos et al ., 2018 a ) adopted by many producers worldwide, and is considered key to intensifying ruminant production in the tropics (Santos et al ., 2020).…”

“…The inclusion of other forage species, such as forage legumes, may contribute to increasing DM content, besides the crude protein (CP) content of silage (Ribeiro et al ., 2020; Lemos et al ., 2021). Among possible options is butterfly pea ( Clitoria ternatea L.), a legume with forage potential that stands out for its tolerance to prolonged drought periods (Abreu et al ., 2014; Santos et al ., 2017, Pereira et al ., 2020).…”