Dual sensor measurement shows that temperature outperforms pH as an early sign of aerobic deterioration in maize silage

Abstract

High quality silage containing abundant lactic acid is a critical component of ruminant diets in many parts of the world. Silage deterioration, a result of aerobic metabolism (including utilization of lactic acid) during storage and feed-out, reduces the nutritional quality of the silage, and its acceptance by animals. In this study, we introduce a novel non-disruptive dual-sensor method that provides near real-time information on silage aerobic stability, and demonstrates for the first time that in situ silage temperature (Tsi) and pH are both associated with preservation of lactic acid. Aerobic deterioration was evaluated using two sources of maize silage, one treated with a biological additive, at incubation temperatures of 23 and 33 °C. Results showed a time delay between the rise of Tsi and that of pH following aerobic exposure at both incubation temperatures. A 11 to 25% loss of lactic acid occurred when Tsi reached 2 °C above ambient. In contrast, by the time the silage pH had exceeded its initial value by 0.5 units, over 60% of the lactic acid had been metabolized. Although pH is often used as a primary indicator of aerobic deterioration of maize silage, it is clear that Tsi was a more sensitive early indicator. However, the extent of the pH increase was an effective indicator of advanced spoilage and loss of lactic acid due to aerobic metabolism for maize silage.

Effects of sodium diacetate or microbial inoculants on aerobic stability of wilted rye silage

“…The increase in silage pH facilitates the growth of opportunistic organisms such as molds, further accelerating silage deterioration [ 5 ]. Therefore, the magnitude of increase in silage pH upon oxygenation could be an indication of the extent of aerobic decay [ 30 ].…”

Effects of fermentative quality of corn silage on lactation, blood metabolites, and rumen fermentation in dairy cows

“…Aerobic deterioration of silage is unavoidable after opening of the silo; therefore, silage quality needs to be checked frequently. For simplified monitoring the degree of aerobic deterioration, so far, changes in temperature or pH have been used as indicators (Shan et al, 2021). We recently demonstrated that one of the nanomechanical sensors MSS for detecting VFAs in silage and showed the sufficient discrimination of the silage samples (Minami et al, 2023).…”

Effects of bacterial inoculants on microbial community, mycotoxin contamination, and aerobic stability of corn silage infected in field by toxigenic fungi during aerobic exposure

“…Once the silage is opened and fed, air freely accesses the silo face and aerobic microorganisms that survived the ensiling process, e.g. bacilli, yeast and acid-tolerant bacteria, can rapidly proliferate, metabolizing residual sugars and organic acids to CO 2 , H 2 O, and heat [14,15]. Consequently, silage temperature increases and the silage mass becomes aerobically unstable.…”