Forage yield, nutritional composition, and aerobic stability of silages from sorghum genotypes and pearl millet under warm-subhumid conditions

Abstract

Silage production from sorghum (Sorghum bicolor (L.) Moench) and pearl millet (Cenchrus americanus (L.) Morrone) is an important strategy to ensure feed availability and quality for ruminants in warm-subhumid regions. This study aimed to evaluate the forage yield, nutritional value, and aerobic stability of silages from 12 sorghum genotypes ('Arcos', `Williams', `Paloma', `Fortuna', `195-2', `197-1', `197-1-1', `Proconsul', `Verde Pacas', `Gladiador', `Gobernador', `Caramelo') and pearl millet to identify alternatives for ruminant feeding. Forage yield was quantified as total DM (TDM), and nutritional composition was determined by crude protein (CP), in vitro digestibility (IVD), neutral detergent fiber (NDF), and acid detergent fiber (ADF); aerobic stability was measured after silo opening. Genotypes `197-1-1' and `197-1' achieved the highest TDM (19.05 and 14.68 t ha(-1), respectively; p < 0.05), but had lower CP (51-53 g kg-1) and higher NDF (674-700 g kg(-1)), resulting in reduced IVD. Pearl millet showed higher CP (109 g kg(-1)), lower NDF (613 g kg(-1)) and ADF (182 g kg(-1)), and higher IVD (602 g kg(-1); p < 0.05). Aerobic stability varied among genotypes: Materials with a greater proportion of panicle and lower fiber content ('Gobernador', `Proconsul') deteriorated faster (40-48 h after opening), while `Verde Pacas', `Gladiador', and `Williams' remained stable for 64 h. The results demonstrate that genotype selection significantly influences silage yield, nutritive value, and stability. Late-cycle genotypes produce greater biomass but lower quality, whereas early or intermediate genotypes offer a better balance between yield, digestibility, and preservation under warm-subhumid conditions.