Effects of ensiling duration on ensiling characteristics and aerobic stability of sugar Napier grass regrowth.

Abstract

ABSTRACT Napier grass (Pennisetum puerperium), a widely used forage crop due to its high biomass yield, is limited in productivity and nutritional value by environmental stresses such as drought. To overcome these limitations, a hybrid of pearl millet (PM) and Napier grass was bred, offering an improved tolerance to harsh climates and higher forage yield. Ensiling using lactic acid bacteria (LAB), a preservation technique used to maintain the nutritional value of succulent forage such as Sugar Napier grass (SNG). Although LAB inoculants are often used in ensiling, the duration of ensiling is a critical factor that directly affects the quality of the preserved forage. This study aimed to investigate the effect of different ensiling durations (7, 14, 21, 28) days on the fermentation characteristics and nutritional quality of sugar Napier regrowth silage. Sugar Napier regrowth harvested material were treated with molasses and a microbial inoculant to assess how extending ensiling periods influence silage quality. The results revealed that ensiling duration significantly affected key fermentation and nutritional parameters. By day 7, the silage exhibited favorable organoleptic qualities, including a light greenish colour, firm texture, and an alcoholic aroma, with no visible mould. Moreover, as the ensiling duration extended to 28 days, there were further improvement in fermentation characteristics, as indicated by a reduction in pH from 4.51 on day 7 to 3.66 on day 28, reflecting more complete fermentation. The extended ensiling duration also positively impacted the nutritional profile of the silage. Crude protein (CP) content increased from 876 g/kg DM on day 7 to g/kg DM on day 28, while dry matter (DM) content improved from 876 g/kg DM to 915g/kg DM. Notably, neutral detergent fibre (NDF) and acid detergent fibre (ADF) concentrations decreased, further enhancing digestibility of the forage as ensiling progressed. Farmers are encouraged to ensile forage for at least 28 days to optimize silage quality.