The effects of molasses and ensiling duration on selected quality parameters of red Napier grass silage

Abstract

This study examined the combined effect of molasses and ensiling duration on nutritive value, selected quality parameters, and in vitro gas production of Red Napier grass, which was ensiled with and without molasses for 30 and 60 days. The experiment was arranged in a completely randomised design with a 2 x 2 factorial setup of treatments in mini plastic bucket silos. Silage samples were analysed for proximate composition and detergent fibre fractions. In vitro gas production was measured to evaluate volume and rate of gas formation. The pH was determined, and the Flieg score, digestible dry matter (DDM), dry matter intake (DMI), in vitro organic matter digestibility, short-chain fatty acids, and microbial protein synthesis were estimated using standard models to assess silage quality. Results showed no significant differences (p>0.05) in DM contents among silages. Comparatively, treatments with molasses had significantly increased (p < 0.05) crude protein, ash, ether extract, and hemicellulose contents, with reduced levels of other proximate and detergent fibre fractions. Except for pH, all other silage quality parameters significantly improved (p<0.05) following the addition of molasses. The inclusion of molasses also significantly (p<0.05) increased fermentative gas volumes, and the rate of gas production was higher for the 60-day ensiling duration. Overall, ensiling duration did not significantly affect (p>0.05) chemical composition, quality parameters, or in vitro gas production of silages. It was concluded that ensiling Red Napier grass with 5% molasses results in changes to silage chemical and fermentation traits, likely improving forage conservation and use.