Effect of Different Sugar-based Additives on the Physico-chemical Quality of Napier (Pennisetum purpureum) Silage

Abstract

Background: Silage is defined as feed or rotation made from crops or farm by-products which are harvested or gathered and placed in a compartment called a silo. It is a crucial component of modern livestock nutrition, and plays a pivotal role in ensuring year-round availability of high-quality forage for livestock. Aims: The study evaluated the quality of Napier silage using different additives by assessing its physico-chemical characteristics such as dry matter content, colour, odour, aroma, texture, pH level, temperature, and mould presence. Methodology: Completely Randomised Design. The experiment was conducted at the Farm Barn House of the Central Bicol State University of Agriculture from March 2 to April 14, 2024. Fresh Napier grass was harvested at 90 days of growth from the small ruminant pasture area of the Department of Animal Science, CBSUA, San Jose, Pili, Camarines Sur. All of the data for the study were arranged, totalled, and statistically analysed using Analysis of Variance (ANOVA) in a Completely Randomised Design (CRD). Any significance was compared using Tukey's Honest Significant Differences Test (HSD). The grass was cut at ground level, chopped into 2–3 cm pieces, and air-dried to achieve approximately 65% moisture. Once the desired moisture content was reached (650 g from 1 kg fresh sample), 57 kg of Napier grass per treatment was prepared for ensiling. Additives—molasses, muscovado, sangkaka (jaggery), and bagasse—were incorporated at 10% of the silage weight (5.7 kg), and the silage was fermented for 35 days. After fermentation, it was opened and evaluated based on the identified quality parameters. Results: The results showed significant differences (p<0.05) in the colour of Napier silage and highly significant differences (p<0.01) in aroma among treatments. However, no significant difference was observed in texture and mould coverage (p>0.05). Other physico-chemical characteristics, such as temperature and pH level, differed significantly (p<0.01), with Treatments 1 (control) and 2 showing notable variation from the others. Meanwhile, dry matter content showed no significant difference across treatments. Conclusion: The results indicated that additives influenced the colour, aroma, temperature, and pH of Napier silage but had no significant effect on texture, mould coverage, and dry matter content. This suggested that the additives improved fermentation and sensory quality without altering the silage’s physical properties.