Online Monitoring of the Temperature and Relative Humidity of Recycled Bedding for Dairy Cows on Dairy Farms

Abstract

In large-scale dairy farming, the use of high-temperature-fermented dairy manure bedding instead of rice husk-based bedding and other commercial types of bedding is widely favored. Strip-stacking aerobic fermentation is the main production method of dairy manure bedding, but it has problems including unstable fermentation and the secondary breeding of pathogens. In this work, a multi-probe, integrated, online monitoring system for temperature and relative humidity was used for fermentation process optimization. The effects of the temporal and spatial distribution of fermentation temperature and relative humidity on the nutrient content curve and the moisture and ash content of manure bedding materials were systematically studied. The effect of the fermentation process on the retention rate of effective bedding materials (cellulose, hemicellulose, and lignin) was analyzed. The experiments proved that high-quality bedding material can be obtained through reasonable stacking fermentation. The fabricated bedding material has a total dry base content consisting of cellulose, hemicellulose, and lignin of 78%, an ash content of 6%, and a nutrient content of 17%. The obtained bedding material was produced to increase the bed rest rate and continuously inhibit the bedding bacteria content, keeping it at a low level for 5 days. This study proves that temperature and humidity monitoring can guide the optimization of the strip-stacking fermentation process of dairy manure and that it can be applied to large-scale farms to improve fermentation parameters.

1. Introduction

In recent years, with the rapid development of the economy, dairy farms have been scaled up, and the amount of dairy manure has become a great challenge for the farming sector [1,2]. Dairy manure places a great burden on the environment and resources [3]. One of the most commonly used methods of manure treatment is using it to fertilize the land. In dairy manure, there are abundant N, P, and S elements, which can also play a role in increasing soil fertility. However, cow manure is produced in large quantities, and the ability of the land to decompose it is limited. Excessive or inappropriate return of manure to the field can cause a number of problems, such as environmental degradation, climate change, resource depletion [4], acidification, and potential eutrophication [5]. Therefore, there is an urgent need for a green treatment method to relieve the pressure placed on the land by manure and improve its degradation process. The use of high-temperature-fermented dairy manure to produce recycled manure bedding materials instead of non-renewable sand and biomass has been widely adopted in large-scale dairy cow farming. Recycled manure bedding could be used as a good alternative to bulk sawdust, wood chips, shavings, square harvesting straw, chopped straw, rice husks, peanut shells, corn cobs, and other commercial biomass bedding materials [6,7,8,9,10,11,12]. Not only can it save costs, but it can also reduce the risk of the introduction of pathogens carried by biomass [13].

Dairy cow mastitis is one of the most common diseases in dairy farming [14]. Pathogen infection is the main cause of mastitis in dairy cows and is closely related to the quality and use of the bedding materials. The pathogenic microorganisms most commonly detected in mastitis milk samples are Escherichia coli (E. coli) [15], Streptococcus agalactiae (S. agalactiae), and Staphylococcus aureus (S. aureus) [12,16,17]. The latter species is the most representative pathogen in milk [18]. The number of bacteria in the bedding material is positively correlated with the type of bacteria on the tip of the cow teat [7]. Cow teats are in direct contact with the bacteria in the bedding material [8,9,17]; therefore, the bedding material is the main source of the teats’ exposure to environmental pathogens that cause mastitis. The improper use of bedding can lead to mastitis outbreaks, which can lead to huge financial losses [11,19].

With the expansion of the scale of automated farming, the demand for bedding material is increasing [10,20]. The methods of high-temperature aerobic fermentation mainly include strip-stacking fermentation, drum-type tank fermentation [20], and membrane fermentation [21]. Among them, strip-stacking composting has been widely used to treat dairy manure because of its high capacity for treatment and low cost [22]. However, the implementation process of the strip-stacking fermentation method makes it difficult to control the quality of the fermented products. Random factors such as the weather, the differences in ambient temperature between the farm and the pasture, and the amount of manual work involved in the process can all affect the final nature of the manure and the sterilization effect. Therefore, there are problems including bacterial regeneration and high-frequency replacement in recycled bedding prepared by strip-stacking fermentation. The climate and environment of every pasture are different in different seasons. Pastures need a long production practice cycle to form a stable aerobic fermentation process, and targeted adjustments need to be made in different seasons throughout the year. However, in actual pastures, it is difficult to flexibly adjust the fermentation process because there is a lack of indication signals. Therefore, it is of great significance to establish a rapid strip-stacking fermentation condition monitoring method to assess the influence of fermentation process parameters on the establishment and optimization of aerobic fermentation processes in large-scale pastures.

At present, the main factors influencing the fermentation process in strip-stacked aerobic compost include stack size, initial moisture content, fermentation time, air permeability, sunshine time, and ambient temperature. The influence of these factors has been widely studied. The evaluation of the quality of dairy manure bedding material mainly includes softness [23], dryness, cleanness, elasticity, and deformation resistance [24,25]. This is related to the dry matter content [15], moisture content [26], cellulose, hemicellulose, and lignin content, particle size [23], and other factors. Shane et al. found that bedding material with good physical structure and good water absorption (moisture content of less than 25% and particle size of less than 2.5 cm) is the best choice for breeding systems [27]. Robles et al. found that the type of bedding material is related to the rate of bacterial growth [28]. Moreover, bacterial growth is closely related to the usage process [15,23]. However, most existing studies only focus on the fermentation process, studying the use of bedding material separately. There are relatively few studies on the interaction between the two processes. Therefore, it is important to establish the relationship between the fermentation process and bedding quality and usage. To the best of our knowledge, there has been no systematic investigation on the use of automatic online equipment to monitor the actual use of strip-stacked bedding fermentation on large-scale dairy farms.

Therefore, in this study, an online detection system for the temporal and spatial distribution of stacking temperature and humidity was established. Long-term continuous detection data of stacking temperature and humidity at different depths was obtained. Variations in the temperature and relative humidity of the stacking section with fermentation time, day and night alternation, and sunny and rainy seasons were analyzed. The pathogenic bacteria killing rate, the content of water and cellulose, and the nutrient particle size were evaluated. Meanwhile, the determination of the fermentation endpoint was realized by combining bacterial detection and online monitoring. It was found that the stacking fermentation process had a significant effect on comfort, bed rest rate, and bacterial reproduction rate.

2. Materials and Methods

2.1. Materials

The materials used in this study included LB nutrient agar (Shanghai Titan Scientific Co., Ltd., Shanghai, China), Staphylococcus aureus chromogenic medium (Shanghai Titan Scientific Co., Ltd.), KF streptococcus agar (Shanghai Titan Scientific Co., Ltd.), MacConkey agar medium (Shanghai Titan Scientific Co., Ltd.), agar powder (Solarbio Science & Technology, Beijing, China), and ethanol (C₂H₆O, ≥99.7%, Sigma-Aldrich, St Louis, MO, USA).

2.2. Strip Stacking Fermentation of Dairy Manure

The experiment was carried out on a large-scale ranch with 5000 cows in western China. The time chosen for this study was July to August during the high-temperature periods. The outdoor daytime temperature was maintained at an average of 30 °C. Dairy manure was scraped to the manure storage tank through the hanging manure board, transported to the dry and wet separation room by the manure pump, and then transported to the fermentation site by machinery after separation (Figure S1a). The fermentation process adopted the strip stack aerobic fermentation method, with a length of 16 m, a trapezoidal cross-section, a bottom width of 2 m, and a height of 1 m, so as to ensure the sufficient mass transfer of water and oxygen (Figure S1b). The whole fermentation process lasted for 15 days. The samples were collected at three different depths as follows: the surface layer (0.05 m depth), the middle layer (0.5 m depth), and the deep layer (1 m depth) for bacterial content and other characterization. Each sample was collected at three locations, and the test results were averaged. The stack was divided into two piles with different fermentation processes, as shown in Figure S2. The A group was spread out and mixed evenly on the 5th and 12th days and then stacked up to return to its original shape. The B group was kept unchanged for 15 days to make a comparison.

After the fermentation was over, the dairy manure of the A and B groups was spread out, dried under the sun, and turned three times a day. The final moisture content decreased to below 10%. The dairy manure bedding material was obtained, sprinkled with slaked lime, and stirred evenly before being used in the barn.

2.3. Temperature and Relative Humidity Online Monitoring

An online monitoring system was used for the detection of temperature and relative humidity, as shown in Figure S1c. The temperature and relative humidity probe contain a detection area with a total length of 0.9 m, and 10 sensors are evenly distributed in the detection area. The data is transmitted to the computer through the network. The detection interval is 30 s. The first sensor is exposed to the outside of the stack and is used to monitor the ambient temperature. Two probes were used for the A group and the B group, respectively. Data from the spreading, drying, and flip processes were discarded.

2.4. Composition Measurement

Moisture content was measured using a halogen moisture analyzer using the differential gravity method. The determination of lignocellulosic fibers (including cellulose, hemicellulose, and lignin) and ash content was measured using the Van Soest method of the reported article [29]. The nutrient content was obtained by subtracting the above substances from the total weight.

2.5. Bacterial Content Measurement

The content of E. coli, S. aureus, S. agalactiae, and Total Bacteria Counts (T. B. Cs) was obtained by combining the solid medium coating plate counting method with the polymerase chain reaction (PCR). Typically, 40 g of LB nutrient agar, 35.04 g of Staphylococcus aureus chromogenic medium, 69.5 g of KF streptococcus agar, and 50 g of MacConkey agar medium were dissolved in 1000 mL of ultrapure water. Meanwhile, 2.4 g of agar powder was added to the above solution and heated at 121 °C for 15 min in an autoclave. After cooling, the medium was solidified, sealed with parafilm, and stored at 4 °C. LB nutrient agar was used to grow T. B. Cs; Staphylococcus aureus chromogenic medium (second generation) was used to grow S. aureus; KF Streptococcus agar (with TTC) was used to grow S. agalactiae; and MacConkey agar medium (containing crystal violet) was used to grow E. coli [30].

The bedding samples were thawed at room temperature, and 0.07 g of a sample was added into 7 g of sterile water. Then, the stock solution was fully shaken and filtered with a vortex mixer to create a 1:100 dilution. After the mixture stood at room temperature for 10 min, 100 µL of the supernatant was taken for further dilution (1:10², 1:10³, 1:10⁴, 1:10⁵, 1:10⁶, or 1:10⁷). The LB nutrient agar medium was inoculated onto a 1:10⁷ dilution; the S. aureus medium and S. agalactiae medium were inoculated onto a 1:10³ dilution; and the E. coli medium was inoculated onto a 1:10⁴ dilution. The dilution was evenly smeared on the disposable medium with a coating rod. After being fully absorbed by the medium, it was placed under aerobic conditions at 37 °C and cultured for 24 h. The number of bacteria was obtained by counting the plate, as shown in Figure S3, Supporting Information.

The polymerase chain reaction (PCR) was detected on a PCR machine (Zimmer Bonmei, Dover, OH, USA), which is used to determine the type of bacteria. Its model is the jy300C electrophoresis apparatus. All specific primers for PCR were designed using Beacon Designer 17.0 software based on the gene sequences available in GenBank [31]. The primer designs for different bacteria are shown in Table S1.

2.6. Bed Rest Rate Measurement

The bed rest rate of dairy cows was measured in a large lactating cow barn in the pasture, covering 500 adult lactating cows. Ten beds among the 200 beds in the barn were selected for collecting bedding samples. About 10 kg of fresh bedding material for each bed is supplemented every 3 days. Previous studies have shown that frequent addition or replacement of bedding material can reduce exposure to mastitis pathogens in the environment [32]. Supplementation of the bedding material was carried out during the milking time to avoid the process of manure throwing affecting the feeding and rest of the cows. The 10 beds were divided into two parts, with bedding materials for the A and B groups. The bedding was laid as shown in Figure S4. On the bed, the thickness of the dairy manure material under the head and the udder of the dairy cows was about 45 cm and 20 cm, respectively. The samples that were stepped on 2–5 cm below the breast were collected every 12 h and stored at −20 °C. The number of cows lying in 5 beds in the A or B group was recorded every 10 min for 120 h during 5 days. The rate of bed rest was based on the ratio of beds with lying cows. In the milking process, the cows were not in the barn, and the data were discarded.

3. Results and Discussion

3.1. Temporal and Spatial Distribution of Temperature

The time-temperature characteristic curve that was collected by the online monitor is shown in Figure 1a,b. For both the A and B groups, there was a periodic change in temperature between 16.4 °C and 45.8 °C at 0.05 m, which is assigned to the ambient temperature. The periodic changes reflected the alternating fluctuations in temperature during the day and night. Therefore, the detection method in this work can also monitor the ambient temperature of a pasture in real time. The results showed that the average ambient temperature during the experiment was about 30 °C. The temperature curves from −0.05 m to −0.85 m showed the temperature at the corresponding depths in the stack. The temperature curves of the −0.05 m and −0.25 m depths synchronously fluctuated with the ambient temperature, indicating the superficial temperature of manure stacks was significantly affected by the ambient temperature. For the A group, the maximum temperature of superficial manure (−0.05 m) was 50.3 °C, which is too low to reach the temperature of complete sterilization. However, the lowest temperature at −0.25 m depth could reach 60 °C during the second to seventh day. The temperature change during the fermentation experiment is a fluctuation in the high-temperature range from 50 °C to 75 °C. Therefore, the temperature fluctuations in this range do not easily alter microbial populations, and the surviving microbial population is bacteria that are resistant to high temperatures. It has been reported in the literature that the minimum sterilization temperature for E. coli and S. aureus is 50 °C and 40 °C [30,33], respectively. Therefore, cow manure must undergo high-temperature sterilization at different depths by flipping over the stack.

The temperature curves were fitted with the stacking section to obtain the temperature distribution map of the stacking section, as shown in Figure 1c–e. A higher temperature (about 75 °C) was achieved at a depth of 0.3 m, about 3 days from the start of fermentation (Figure 1c). The high temperature gradually expanded to a depth range of 0.25~0.65 m on the fifth day. This result proves that temperature accumulation is raised from the outside to the inside, and only a shallow layer (<20 cm) of manure insulation is required. The temperature curves at the 0.45 m and 0.65 m depths exhibited the highest temperature (73.4 °C to 69.4 °C) without noticeable fluctuations, indicating the best fermentation and sterilization intervals. The temperature in this zone can be recovered within 35 h after the 5th and 12th days of flipping the stack. The temperature recovery on the 12th day was quicker than the 5th day because of more aerobic bacteria. Therefore, it is necessary to maintain the fermentation time for at least 5 days after each flipping of the stack to ensure a high-temperature environment.

Next, the difference in temperature distribution between the A and B groups was compared and shown in Figure 1d,e. The A group could quickly rise to a high temperature (~73.4 °C) after turning the stack, and the high temperature could be maintained until the end of the stacking. However, the B group showed an obvious decrease in temperature from the 10th day to the 15th day. After the nutrient depletion in the middle depth of the B group, the number of beneficial bacteria decreased, resulting in a decrease in temperature. Nutrients in other low-temperature areas of the B group may breed pathogens that are not killed.

3.2. Temporal and Spatial Distribution of Relative Humidity

Since bacterial growth is related to relative humidity (RH) [20], a time-relative humidity characteristic curve according to the monitoring data was investigated, as shown in Figure 2 and Figure S5. In the first 5 days (Figure 2c), the distribution of RH was closely correlated with temperature. The more active the bacteria, the higher the temperature and RH. The deepest relative humidity was more than 100%, which exceeded the upper limit of detection. Because of the compaction of the manure on the surface, it is difficult for moisture to diffuse outside, and excessive RH affects the diffusion of oxygen.

After flipping the stack, there was a significant difference in the RH distribution between the A (Figure 2c) and B (Figure S5b) groups. In the A group, areas with high RH were only found in the bottom area of the stack. Flipping the stack could effectively maintain the permeability of the stack with RH < 25% so that the moisture generated by bacterial activities could be emitted over time. In addition, the −0.85 m depth of the B group showed an increasing RH from 20% to 100% (Figure S5a), indicating the anaerobic fermentation in the deep area is the gradual accumulation of water. In the high-RH region at the bottom, the A group also had a smaller range than the B group, indicating a smaller anaerobic area. Therefore, the flipping of the stack is conducive to the diffusion and mass transfer of water and helps to reduce the distribution of anaerobic fermentation areas and the generation of stench, such as H₂S and NH₃ [34,35], while promoting aerobic fermentation.

3.3. Moisture Content Analysis

Next, changes in the water content of the stacks during the fermentation process were investigated. As shown in Figure 3, the moisture content was 65–75% in the first 2 days, which was similar to that reported by Black R.A et al. [28]. Bacterial growth is affected by moisture and will also affect water cumulation [20]. The moisture content reached its maximum on the third day because of bacterial metabolism, and the moisture content in the deep layers was as high as 75%. From the curves of the A and B groups, it can be seen that the moisture content of manure did not change during the fermentation process, regardless of whether the pile was turned over or not. The removal of water from bedding materials mainly depended on the drying process (after the 15th day). Therefore, the initial moisture of the manure before fermentation needs to be strictly controlled. Too much moisture (>70%) will limit air permeability [36], and too low moisture (<30%) will affect the reproduction of beneficial bacteria [37].

The moisture content of the surface manure in the B group decreased on the third to ninth days. This process of water loss is the result of surface manure compaction. On the ninth day, because of rain, the moisture content of both groups increased in both the surface and middle layers, but the rain did not penetrate into the deep layer. Therefore, open-air fermentation is tolerant to general rain and snow weather, and the fermentation inside the stack is not easily affected by general rainfall. After the 15th day, the two groups of dairy manure were spread out and mixed evenly, and the moisture content decreased rapidly with an average rate of 4% per day.

3.4. Bactericidal Performance Evaluation

The number of bacteria in the recycled bedding produced by the A group was obtained by plate counting, as shown in Figure 4. As shown in Figure 4a, the number of E. coli at the beginning of fermentation was about 10⁶ CFU/g, which is similar to the results of the work reported in [9]. E. coli was eradicated after 3 days at 0.5 m, quicker than that of 5 days at 0.05 m, and 7 days at 1 m, indicating that the middle layer had a better bactericidal effect. Llonch et al. reported the same result [32]. As shown in Figure 4b, the same change occurred in the superficial layer and middle layer of S. agalactiae, but the difference was that this species was eradicated on the fifth day in the deeper layer. S. aureus was not detected in the entire experiment (Figure 4c). The number of T. B. C was measured, as shown in Figure 4d. The number of T. B. C was about 10⁹ CFU/g at the beginning, which is more than previously reported [9]. On the 12th day, the number of T. B. C sharply increased because of the breakdown and decay of cellulose to provide more nutrients. Therefore, 15 days of fermentation time is sufficient to achieve good sterilization. A fermentation time that is too long will make the manure rot, which is not conducive to improving bedding quality.

3.5. Composition Analysis

The composition analysis of lignocellulosic fibers, nutrients, and ash was carried out to compare the effect of the flip stack on bedding between the A and B groups. These lignocellulosic fibers are mainly composed of cellulose, hemicellulose, and lignin [38]. Lignocellulosic fibers are a measure of the indigestible plant material in livestock. Crude fiber is determined by acid and alkaline treatment of the sample to remove soluble carbohydrates, proteins, and ash, leaving the insoluble fiber fraction. It includes neutral detergent fiber (NDF) and acid detergent fiber (ADF) [39]. The composition analysis of the dry matter results of the A and B groups is shown in Figure 5. During fermentation, the nutrients decreased for both the A and B groups because of the gradual increase in the number of beneficial strains during the fermentation process, which coincides with the number of T. B. C. in Figure 4. Several beneficial bacteria in cow manure have been reported, such as Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria [40]. These bacteria could degrade the nutrients in cow manure and produce a high temperature to kill the eggs of pathogenic bacteria. In the former 5 days, the nutrient content decreased from 21–27% to 10–17%, and the superficial layer and middle layer decreased significantly, by about 13%, showing a similar trend in the two groups. The deep decline is slow, by about 16–17%. Because oxygen and moisture can be diffused by mass transfer, aerobic fermentation dominated in the middle and upper layers. But the oxygen could not transfer into the deep layer, so anaerobic fermentation dominated. During anaerobic fermentation, short-chain fatty acids and dicarboxylic acids (such as fumaric acid) could be produced [41]. These short-chain fatty acids and dicarboxylic acids can provide nutrients to the bacteria but are not conducive to the long-term use of the litter. Therefore, anaerobic fermentation needs to be avoided as much as possible.

Comparing the difference between the A and B groups, the rate of nutrient consumption in the A group was faster than that in the B group, indicating that flipping the stack increased the mass transfer of water and oxygen, promoting aerobic fermentation [42]. Flipping the stack is the switch between the A and B groups that regulates aerobic and anaerobic fermentation. In this work, the stack of the A group was flipped twice, while the B group was not flipped. The total contents of the lignocellulosic fiber, including cellulose, hemicellulose, and lignin, increased from 75% to 83% (0.05 m depth), 82% (0.5 m depth), and 78% (1.0 m depth). Mono-anaerobic digestion (AD) of dairy cow manure is constrained by ash [43]. Improving and retaining fibrous matter in dairy manure is an important reason why fermentation can make recycled bedding. The A group presented a higher lignocellulosic fiber content than the B group, indicating a better fermentation performance. It was also found that in the samples at the 1.0 m depth, the B group had a higher hemicellulose content of 26% than the A group (21%), while the cellulose content decreased from 33% (A) to 29% (B). This result indicates that there is excessive decomposition in the B group, which dissociates cellulose to form hemicellulose. The additional flipping of the stack in the A group can effectively reduce over-fermentation and decay.

3.6. Bedding Bacteriostatic Performance

Before the actual application in the barn, the bacterial reproduction of the bedding materials with and without the influence of dairy cows was investigated. The A and B groups of recycled dairy manure bedding materials were mixed evenly with hydrated lime. The recycled manure bedding materials were placed in the barn environment (26.4 °C for daytime, 20.6 °C for night, and 56.2% of RH), and samples were taken regularly to observe changes in bacterial levels (Figure 6). E. coli, S. agalactiae, and S. aureus were not detected in the A group. But E. coli increased to about 2 × 10⁶ CFU/g in the B group after 12 h. At 36 h and 96 h, adding new bedding material and hydrated lime according to the actual use process could slightly reduce the number of E. coli, but the effect was minimal. In the absence of dairy cows, the secondary growth of E. coli in the B group was delayed until 36 h, with an E. coli content of 5.5 × 10⁵ CFU/g. Therefore, cleaning up manure timely will increase the cleanliness of bedding, thereby increasing milk production [20]. This comparison result proves that the recycled bedding material of the A group can effectively extend the service life and inhibit the secondary reproduction of pathogens because of its low nutrient content and complete sterilization of pathogens. In general, the dairy manure bedding material obtained by the group A method is used for no less than 5 days with dairy cows, so it is recommended to replenish with fresh litter every 3–5 days.

3.7. Bed Rest Rate Measurement

Adequate bed rest for dairy cows helps to increase milk production [44,45]. The average bed rest time of dairy cows is 8–16 h per day [46]. The bedding time of dairy cows depends on the type of dairy manure, and the bedding time of the cow will increase significantly when the bedding material is comfortable and relatively dry [46]. In this study, the A and B groups of recycled manure bedding materials were thrown onto the cow bed to count the number of cows lying in the bed (Figure 7a). During the experiment, the bedding needed to be 45 cm thick below the head and 20 cm below the udder, as shown in Figure 7b and Figure S4. Sufficient bedding materials can reduce lameness and some lesions [47]. The number of curves of cows lying in a bed according to the monitoring are shown in Figure 7c. It can be clearly seen that the bed rest rate of the A group is significantly higher than that of the B group, which proves that the fermentation mode of dairy manure in the A group brought better comfort than that of the B group.

To determine the reasons for the increase in comfort, particle size analysis was carried out (Figure 7d–f). A series of samples of different depths (0.05 m, 0.5 m, and 1.0 m) were collected on the first day (marked A-1 and B-1 for the A and B groups, respectively) and the 15th day (A-15 and B-15). The results prove the recycled bedding materials of the A group better retained their original granularity. The B group decreased the particle size because of decay, which was consistent with the composition test results of partial cellulose conversion to hemicellulose. Therefore, the statistical results of the bed rest rate and the particle size test prove that the flipping of the stack could improve the comfort of recycled manure bedding materials.

4. Conclusions

In this work, the spatial and temporal distribution characteristics of temperature and RH were drawn according to the online monitoring system. The changes in moisture content, number of bacteria, lignocellulosic fibers, and nutrient and ash content of recycled dairy manure bedding materials were detected during 15-day strip-stacked aerobic fermentation. The effects of flipping manure stacks on the bedding material composition, antibacterial properties, and bed rest rate were compared. The work proves flipping over manure stacks facilitates the diffusion of water and oxygen in the stack, retention of more cellulose, and improvement in bed rest. Within 48 h after flipping, the high stacking temperature will be recovered. The dairy manure shell formed by not flipping for a long time affected heat and mass transfer, which was not conducive to fermentation, leading to enhanced anaerobic fermentation and over-ripening. This work proves that in situ online temperature and RH monitoring combined with ex situ detection can effectively explore the rationality of large-scale pasture fermentation processes. This online monitoring system can better realize the automation of farm production and control. This monitoring method can be potentially applied in large dairy farms to optimize the process by designing the fermentation process and monitoring the daily bedding production process.