Study On Precise Track Of Aerobic Response And Model Validation For Silage Production Exploring Advanced-sensor Technology

The risk of silage reheating aerobic-induced could be quite high when the plastic cover of silage is damaged during the storage phase or when silage exposes itself to air before feeding.The degree of deterioration can be diagnosed through biochemical or microbiological or physical indices,such as concentration of oxygen(O2)against that of carbon dioxide(CO2),growths of microorganisms and abnormal rises of internal temperature and pH.Here we present the first multi-sensor-based,simultaneous measurements of internal O2,CO2,?P,pH,and internal silage temperature(Tsi)over the whole silage-making process.To simulate silage aerobic deterioration relative to an exposure surface of bunker silo,a partial differential equation system model(Pitt-Muck Model)including oxygen(O2)concentration,silage temperature(Tsi)rise and microbial activity was presented.According our study showed general well-agreements between the model simulations and the in situ measurements of O2 and Tsi for all bulk density(BD)levels.Some uncertainties and relevant reasons were also addressed.Based on these results,we concluded that the model has sufficient ability to predict aerobic deterioration in silage for bunker silos being unloaded.This study was financially supported by the Chinese-German Center for Scientific Promotion under Project No.GZ888.The major research works and conclusions of this study can be briefly summarized as follows:(1)Abnormal rise of temperature in silage is regarded as a signal of aerobic deterioration caused by the permeation of atmospheric oxygen into the silage,which indicates the growth of lactate-assimilating yeasts and energy release.To spatially assess any aerobic deterioration within round-bales silage,we modified a bale penetrometer that is capable of profiling temperature distribution.We presented two mapping methods,one for two-dimensional(2D)cross-sections and one for three-dimensional(3D)volumes.To demonstrate the applicability of the proposed method,six representative samples of round bales with varied damage to plastic covers were tested.All temperature patterns,generated in both 2D-and 3D-space,were informative and clearly interpretable.Therefore,we conclude that the tested measurement method can benefit advance of bale silage research and production.(2)There is a high risk of silage spoilage near the zone of the exposure face when a bunker silo is opened for livestock feeding.High silage bulk density(BD)can significantly reduce aerobic deterioration because the high BD creates low porosity,thereby reducing O2 diffusion into the silage.In this study,a penetrometer-based mapping system was developed.We also presented a comparison between the map-based BD results and core sampling data.Agreement between the two measurement approaches(RMSE = 19.175 kg m-3)demonstrates that the developed penetrometer mapping system may be beneficial for rapid assessment of aerobic deterioration potential in bunker silos.(3)Reintroduction of the oxygen from a leak or the feed-out process results in silage degradation.Monitoring silage O2 concentration and temperature(Tsi)can provide critical insight regarding silage quality.Here we firstly applied oxygen sensor(RE 50)and thermocouple(DS18B20)simultaneous monitoring of O2 and Tsi to track silage aerobic deterioration.The experimental results demonstrated that the COE can be an important monitoring tool for assessing the O2 dynamics throughout the silage lifecycle.(4)To simulate silage aerobic deterioration relative to an exposure surface of bunker silo,a partial differential equation system model including oxygen(O2)concentration,silage temperature(Tsi)rise and microbial activity was presented.The model was computed taking the in situ measurements of O2 and Tsi to be targets by using O2 sensor.Our study showed general well-agreements between the model simulations and the in situ measurements of O2 and Tsi for all BD levels.Based on these results,we concluded that the model has sufficient ability to predict aerobic deterioration in silage for bunker silos being unloaded.(5)Based on the multi-sensor based system,we reported the first observation that CO2 produced from microbial respiration was partially dissolved in silage water,with evidence of negative or positive AP depending on the changing balance between CO2 production and dissolution.