Effect of Fermentation Time on the Physical Quality of Sweet Potato Leaf Silage (Ipomoea batatas L.) Fermented Using Rumen Liquid Starter

Abstract

Silage is one of the most widely used forage preservation methods to maintain the availability of quality feed throughout the year. Sweet potato leaves (Ipomoea batatas L.) have considerable potential as silage raw material due to their abundant availability and reasonably good nutritional content. This study aimed to determine the effect of fermentation duration using rumen fluid as a starter on the physical quality of sweet potato leaf silage. The study was conducted using a completely randomized design (CRD) with four fermentation duration treatments, namely 0, 7, 14, and 21 days, each with four replications. Physical quality parameters observed included pH, color, aroma, texture, and the presence of mold in the silage. The results showed that fermentation for 7 to 14 days produced an optimal pH ranging from 3.63 to 4.13, indicating a well-progressing lactic acid fermentation process. During this period, the silage retained its natural green color, exhibited a typical fermentation sour aroma, and had a soft, non-slimy texture. In contrast, fermentation for 21 days demonstrated a decline in physical quality, characterized by an increase in pH to 5.75, discoloration to a dark brownish color, the emergence of a putrid, sour odor, an overly mushy texture, and uncontrolled mold growth. These conditions indicate the occurrence of secondary fermentation that is detrimental to silage quality. Based on these findings, it is concluded that the optimal fermentation duration for sweet potato leaf silage using rumen fluid as a starter is 7 to 14 days, as it produces silage with good physical characteristics, an ideal pH value, and controlled mold growth.