The production of quality animal forage is fundamentally linked to the management strategies employed during cultivation. A recent study sheds light on the optimal conditions for ensiling BRS Capiaçu elephant grass, determining how different regrowth ages and residue heights impact both biomass production and silage quality. Conducted at the José Henrique Brusqui Experimental Field, part of Embrapa Gado de Leite, Brazil, the research examined four distinct regrowth ages—75, 90, 105, and 120 days—and two residue heights—10 and 50 cm—via a randomized complete block design incorporating 3 replicates.
Notably, the study found significant trends correlational to regrowth age. The dry mass production (DMP) of the forage exhibited linear increases as the regrowth period extended. Specifically, the maximal DMP was recorded at 120 days, yielding approximately 62.74 tons per hectare per year, marking an 89% increase from the 75-day age group. Lower residue heights facilitated higher DMP, with grasses cut at 10 cm achieving 53.6 tons per hectare compared to 42.3 tons with 50 cm residue height.
Understanding the balance between quantity and quality is pivotal. The research highlights, "Management using a 105-day regrowth period and a 10-cm residue height resulted in the best balance between dry mass production, fermentative profile, and nutritional value of silage.” This balance is key due to the intersecting needs of sustainable biomass production and high nutrient density for livestock feed.
The varying effects of plant maturity were also apparent concerning silage fermentation quality. Increased maturity led to linear declines in digestibility, crude protein concentration, and total digestible nutrients. Consequently, though increasing regrowth age boosts DMP, it also correlates with reduced nutritional quality, particularly at the later ages of 120 days, when both digestibility and nutrient levels decreased substantially.
The study’s methodology emphasized pH measurement of the silages produced, which ranged from optimal levels indicating successful fermentation. Said study highlights the pivotal role of lactic acid bacteria (LAB) during this process, demonstrated through the control of undesirable microorganisms, as the lowest pH values were recorded at lower residue heights. Specifically, the pH was diminished through effective fermentation, allowing for the preservation of silages.
This research adds to the growing body of evidence demonstrating the importance of micromanaging growth practices as the grass matures. According to the authors, “Understanding forage productivity and quality under different management strategies is pivotal due to its impact on animal performance.” The findings underline the connection between proper management strategies and ensuing animal health and productivity.
Concluding the research, the recommendations advocate for harvesting BRS Capiaçu elephant grass at 105 days with residues maintained at 10 cm for optimal forage mass. This not only maximizes dry matter recovery but also adequately positions silage for nutritional quality. Future inquiries are encouraged to explore the practical applications of this silage on livestock, unraveling its influence on productivity and well-being.