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Simple Summary: The search for housing systems that contribute to increases in productivity and milk quality with the meticulous use of resources is one of the main challenges with modern livestock. In this sense, the compost-bedded pack barn (CBP) is a promising alternative for raising dairy cattle. However, answers regarding the applicability of this system to the conditions of tropical and subtropical climates are lacking, focusing on Brazil. The objective of this study was to gather and describe the most recent information on open and closed CBP for dairy cattle. Properly designed, open CBP facilities with suitably designed ventilation systems and effective bedding management show potential for the climatic conditions and building typologies in Brazil. Most studies on the closed CBP system have provided only preliminary impressions because limited amounts of data have been collected. The first results demonstrate serious challenges with bedding management. The discussed results can be used to guide decision-making processes to create suitable environmental conditions for CBP systems. The main challenge in milk production has been to maintain a focus on efficient processes that enhance production outcomes while aligning with animal welfare and sustainability and being valued by society. As an alternative to improve cow welfare in production and provide better handling of the waste generated by the activity, the system called the compost-bedded pack barn (CBP) has been widely adopted in countries with temperate climates and higher milk production. This CBP has been attracting global interest, including from countries with tropical and subtropical climates, such as Brazil, where many producers have started to use it due to the response in terms of milk productivity. A CBP can be designed either in (a) an open facility with natural ventilation or a positive-pressure ventilation system or (b) totally closed facilities, equipped with negative-pressure ventilation systems and permanent thermal control. The latter system is being implemented in Brazil, despite insufficient knowledge about its efficiency. The objective of this study was, through a review, to gather and describe the most recent information on the use of open and closed CBP systems for dairy cattle housing, mainly covering how it is applied in tropical climate regions. To achieve the proposed objective, this review study included the following topics related to CBPs: (i) implementation, (ii) bedding, (iii) general construction and architectural characteristics, and (iv) ambient thermal conditioning. Knowledge gaps and directions for future research are also identified here. [ABSTRACT FROM AUTHOR]

This systematic review was conducted to describe and discuss the main research findings available in the literature concerning the health and thermal comfort of dairy cattle housed in Compost-Bedded Pack Barn (CBP) systems, in comparison to Free Stall (FS), Tie-Stall (TS), and/or Loose Housing (LH) systems. Searches for peer-reviewed experimental articles in English were performed in the Scopus and Web of Science databases. Forty-three non-duplicated scientific articles were obtained and subjected to a four-stage evaluation process, according to the PRISMA methodology and predefined eligibility criteria. This process resulted in the selection of 13 articles for inclusion. Regarding animal health, the results provide evidence that the incidence of problems such as lameness, limb injuries, and reproductive disorders is lower in CBP systems. However, if bedding management is not effective in ensuring the provision of dry and comfortable surfaces, an increase in somatic cell count (SCC) and prevalence of mastitis incidence (PMI) may occur. For thermal comfort, it was found that the CBP system exhibited higher temperatures during summer and lower temperatures during winter when compared to FS with cross-ventilation in association with evaporative cooling. However, no differences were observed in terms of thermal comfort in spring and autumn. As this is a recent research area, caution should be exercised when extrapolating the results, considering the specificities of each cited study. [ABSTRACT FROM AUTHOR]

In this study, a systematic review was performed to describe and discuss the main results available in the literature on physicochemical bedding quality in compost-bedded pack barn (CBP) systems for dairy cows. Experimental peer-reviewed articles in English were searched in the Scopus (ScP) and Web of Science (WoS) databases. The resulting articles (n = 162) underwent an evaluation process in four stages, following the PRISMA methodology and, based on a priori-defined eligibility criteria, 12 were selected. Several indicators of bedding quality were used, emphasizing bedding temperature in the aerobically active layer, evaluated in all studies. The decomposition activity was less intense in winter due to mild environmental conditions. During this period, appropriate management practices should be used (more frequent bedding replacement and turning, use of aeration systems under the bedding, lateral closures in the facilities, etc.) to maintain the fully active composting process. In conclusion, the physicochemical bedding quality in this system type is mainly affected by environmental conditions. However, some care is needed to extrapolate these results since this is a recent research area, which still requires further studies. [ABSTRACT FROM AUTHOR]

To ensure a supply of dairy products, modern dairy farming has assumed an intensive nature, characterized by production in collective facilities with the presence of thermal conditioning, some automation level, and high-use inputs. Among the systems used for dairy cattle confinement, Compost-Bedded Pack Barns (CBPs) have been gaining importance and increasingly have been used in recent decades. CBPs must be designed and managed to ensure the best thermal comfort conditions throughout the year and, consequently, improve productivity, milk quality, and the health of the dairy herd. In this context, modeling via Computational Fluid Dynamics (CFD) emerges as a tool with huge potential for studying the thermal environmental conditions in the beds of CBPs, making it possible to improve projects and/or management practices in this kind of facility. This document is organized as a review, and its objective is to present the state of the art of the applicability of the CFD technique in the study of heat and mass transfer in CBP systems. So far, only four studies have used CFD for modeling CBP systems and have shown that the use of this tool helps to better understand the phenomena of heat and mass transfer in this kind of facility. Therefore, it is important that more studies using this technique in CBP systems be conducted, including additional considerations on constructive elements, animals, and the presence of beds in composting. [ABSTRACT FROM AUTHOR]

Simple Summary: The use of compost-bedded pack barn (CBP) systems for dairy cattle housing can improve animal welfare and herd productivity, but it is necessary that the bedding is properly managed. Therefore, evaluating the bedding quality conditions in this confinement system is paramount, as the results obtained can be used as a basis for adequate management. In this study, bedding attributes were mapped in a CBP with positive pressure ventilation. From the mapping, it was possible to identify areas with unsuitable conditions for the staying of the cows (surface) and for the composting process (at 0.2 m depth). The results achieved in this study can be used to guide decision-making processes regarding bedding management in this housing system. The objective of this study was to characterize the dependence and spatial distribution of bedding attributes in an open compost-bedded pack barn (CBP) system with positive pressure ventilation during the winter period in Brazil. The study was conducted in July 2021, in the Zona da Mata region, Minas Gerais, Brazil. The bedding area (shavings and wood sawdust) was divided into a mesh with 44 equidistant points. At each point, the bedding temperature at the surface (tB-sur) and at a depth of 0.2 m (tB-20) and the air velocity at bedding level (vair,B) were measured, and bedding samples were collected. The bedding samples were used to determine the moisture level and pH at the surface (MB-sur e pHB-sur) and at a depth of 0.2 m (MB-20 and pHB-20). The spatial behavior of the variables was evaluated using geostatistics techniques. For all variables, the occurrence of strong spatial dependence was verified. Through the maps, it was observed that tB-sur, tB-20, MB-sur, MB-20, and vair,B showed high spatial variability, whereas pHB-sur and pHB-20 demonstrated low variation. On the surface, values of tB-sur < 20 °C and MB-sur > 60% were observed. At the subsurface, there was a predominance of tB-20 < 40 °C, MB-20 > 60%, and pH > 9, which are indications of low bedding composting activity. [ABSTRACT FROM AUTHOR]

Simple Summary: Studies on the effect of thermal stress on lactating cows have increased considerably in recent years. Feedlot systems for dairy cows have become popular around the world. This article aims to develop a scientometric analysis to evaluate studies on thermal stress in lactating cows housed in a free-stall, tie-stall, and compost-bedded pack barn system. A total of 604 studies from the Web of Science database was considered for this study. The data obtained from the Web of Science was exported to Citespace software. The most used keywords by the researchers were "heat stress", "dairy cow" and "cattle". The most relevant countries, authors, institutions, and networks of co-occurrences for our research were highlighted. This article provides a comprehensive review of thermal stress in lactating cows housed in confinement in the last 22 years and contributes to future research in this area. Due to climate change, heat stress is a growing problem for the dairy industry. Based on this, annual economic losses in the dairy sector are verified mainly on a large scale. Despite several publications on thermal stress in lactating dairy cows in confinement systems, there need to be published reviews addressing this issue systematically. Our objective was to scientometrically analyze the effects of heat stress in dairy cows managed in a confinement system. Based on PRISMA guidelines, research articles were identified, screened, and summarized based on inclusion criteria for heat stress in a confinement system. Data was obtained from the Web of Science. A total of 604 scientific articles published between 2000 and April 2022 were considered. Data was then analyzed using Microsoft Excel and CiteSpace. The results pointed to a significant increase in studies on heat stress in lactating cows housed in confinement systems. The main research areas were Agriculture, Dairy Animal Science and Veterinary Sciences. The USA showed the highest concentration of studies (31.12%), followed by China (14.90%). Emerging themes included heat stress and behavior. The most influential journals were the Journal of Dairy Science and the Journal of Animal Science. The top authors were L. H. Baumgard and R. J. Collier. The leading institutions were the Chinese Academy of Agricultural Sciences, followed by the State University System of Florida and the University of Florida. The study maps the significant research domains on heat stress of lactating cows in confinement systems, discusses implications and explanations and highlights emerging trends. [ABSTRACT FROM AUTHOR]

Simple Summary: In the dairy farming system that uses compost barns, animals remain in a large area covered with organic material and are free to move and express their behaviors in a more natural way. The compost barn system has become popular in recent years because it provides greater well-being and quality of life, favoring animal productivity and longevity. The aim of this paper is to develop a bibliometric analysis to evaluate scientific studies about compost barn systems. A total of 108 databases, considering articles and literature reviews obtained from the Scopus and Web of Science databases were considered for this analysis. After standardizing the data, the resulting spreadsheet was analyzed with VOSviewer software. The keywords most used by the authors were "compost-bedded pack barn", "dairy cow", and "dairy cattle". The most relevant countries, journals, institutions, researchers, and co-citation networks to compost barn research were highlighted. The analysis confirmed a significant interest in the spatial variation in the sheds and their relationship with milk quality, heat stress, and animal welfare. This paper provides a great contribution related to the scientific evolution and the research and publishing tendencies of studies on the compost barn animal housing system. The objective of this study was to evaluate the main scientific studies addressing the topic of compost barns in recent years, highlighting the main journals, authors, countries, organizations, and keywords associated with the publications and trends in this type of research through a bibliometric analysis. For this analysis, publications (articles and literature reviews) addressing compost barns were obtained from the Scopus and Web of Science databases. A total of 108 studies published between 2007 and April 2022 were included. A greater number of publications was observed starting in 2017, with 2021 having the largest number of publications. The Journal of Dairy Science was the most highly cited journal. Marcia I. Endres was the author with the greatest academic impact. The most influential country was the United States, followed by Brazil. Among the organizations that have published studies on compost barns, the Federal University of Lavras, and the University of Florence had the largest numbers of publications. In conclusion, this bibliometric analysis allowed us to evaluate the scientific evolution, research, and publishing tendencies of studies on the compost barn animal housing system, and the results make it possible to deduce current trends in scientific research and publications. [ABSTRACT FROM AUTHOR]

Simple Summary: Among animal facilities, compost-bedded pack (CBP) barns have attracted a lot of attention from milk producers and the scientific community. Systematic investigation of the main thermal, chemical, and physical properties of bedding materials in CBP barns is of environmental and economic relevance, helping dairy producers operate these beds properly. Here we assessed 42 CBPs in the state of Kentucky (USA), aiming to study the thermal, chemical, and physical properties of bedding materials. We found that thermal conductivity increased with increasing particle size. Regarding chemical features, the assessed CBPs were similar when considering the bedding materials. The particle weight fraction found in CBPs might result in excessive water retention and low aeration. Based on these main results, we concluded that many dairy producers could use the bedding compost to fertilize their crop fields and avoid over-applying nutrients, and reduce water pollution. The thermal, chemical, and physical properties of compost bedding materials play an important role in every phase of compost production. Based on this, we aimed to assess the thermal, chemical and physical properties of bedding materials for compost-bedded pack (CBP) barns. The database for this study was registered from 42 CBP barns, distributed throughout the state of Kentucky (USA). The thermal conductivity showed a linear relationship with moisture content and bulk density, while thermal resistivity decreased with increasing particle size. The bedding moisture average was 46.8% (±11.5). The average finer index (p < 0.05) was the highest weight percentage (30.1%) in the samples studied. Water-holding capacity (WHC) increased with increasingly fine particle size. The higher bulk density value was 3.6 times that of the lowest bulk density value. The chemical characterization of the bedding material provided the following results: 42.7% (±3.8%) C, 1.6% (±0.4%) N, and 28.2 (±8.0) C:N ratio. However, thermal properties are strongly dependent on particle size. Producers can use the bedding material as fertilizer in their crops, due to the chemical characteristics of the materials. Beds with good physical and chemical properties improve their moisture content. [ABSTRACT FROM AUTHOR]

Simple Summary: Adequate environmental conditions are essential to ensure the wellbeing and productivity of dairy cattle. The use of compost-bedded pack barn (CBP) systems in dairy farming certainly improves animal welfare conditions, but it is necessary to evaluate and characterize the thermal environment inside the facilities. The main objective of this study was to map the thermal environment inside a CBP system with positive-pressure ventilation. Through mapping, it was possible to identify regions with more challenging conditions for animals in terms of thermal comfort. The results achieved can be used to direct decision-making processes to create adequate environmental conditions for the hosted animals. The objective of this study was to evaluate and characterize the dependence and the spatial and temporal distribution of variables and indices of the thermal environment in an open compost-bedded pack barn system with positive-pressure ventilation (CBPPV) during the winter period. The study was conducted in a CBPPV system located in the Zona da Mata region, Minas Gerais, Brazil. The indoor environment was divided into a mesh composed of 55 equidistant points, where data on dry-bulb air temperature (tdb) and relative humidity (RH) were collected. The collected data were divided into four periods—dawn, morning, afternoon, and night—and mean values were obtained. To evaluate the thermal microenvironment, the temperature and humidity index (THI) and the specific enthalpy of air (h) were used. For spatial dependence analysis, geostatistical techniques were applied. Through the results, a strong spatial dependence was verified for all variables evaluated. Through THI and h maps, conditions of thermal comfort were found for dairy cattle. The highest values of tdb, THI, and h were recorded in the afternoon period in the northwest region of the facility (tdb = 23.2 °C, THI = 69.7, and h = 50.9 kJ∙kg of dry air−1). [ABSTRACT FROM AUTHOR]

Simple Summary: It is known that improving the welfare of cows increases dairy productivity. A compost-bedded pack barn equipped with evaporative cooling pads to regulate the inside environmental conditions of dairy seems to be a synergic combination to improve substantial the welfare in dairy facilities. However, there is a lack of information about both techniques working together. A computational model of a tunnel-ventilated compost-bedded pack barn with an evaporative pad cooling system was developed to know the spatial distribution of temperature, relative humidity and velocity of the air inside the barn. These variables allowed us to compute a thermal stress index for dairy cattle to identify the geometric characteristics and operative conditions of the evaporative pad cooling that provide the best environmental conditions inside the barn according to the outside environmental conditions. Evaporative cooling is one of the most efficient techniques to reduce heat stress in cows in agricultural facilities. Additionally, compost-bedded pack barn has been shown to improve the welfare and production of cows. Two techniques were combined and analysed by developing a computational fluid dynamics (CFD) model of a tunnel-ventilated compost-bedded packed barn that integrated the heat and airflow dynamics of an evaporative pad cooling system. This allowed us to study the distribution of dry-bulb temperature, relative humidity and airflow velocity inside the barn based on the external environmental conditions, thickness of the pad, water temperature and specific manufacturer characteristics of the pad, providing optimal cooling pad location, size and operating conditions in the barn. Employing experimental data the CFD model was validated showing good agreement. The Equivalent Temperature Index for dairy Cattle (ETIC) was used to determine the level of stress of the cows considering the airflow velocity. It was found a moderate stress due to high relative humidity and low airflow velocity. From the predicted results, it was recommended to increase the airflow velocity above 3 m s − 1 when simultaneously the external dry-bulb temperature and relative humidity exceed 30 °C and 55%, respectively, simultaneously. Additionally, installation of baffles at the pad outlet to drive the airflow to the floor was suggested to improve the drying of the compost-bedded closed to the pads, where a low airflow velocity region was established. [ABSTRACT FROM AUTHOR]

Featured Application: The findings are highly relevant for the roof design in naturally ventilated compost bedded pack barns. Compost bedded pack (CBP) barns have been receiving increased attention as an alternative housing system for dairy cattle. To create a satisfactory environment within CBP barns that promotes a good composting process, an adequate air movement and minimal temperature fluctuations throughout the building are required. Therefore, a study based on compost barn structure model employing techniques of dimensional analysis for naturally ventilated buildings was developed. Three-dimensional computational fluid dynamic (CFD) simulations of compost barns with different ridge designs and wind direction, along with the visual demonstration of the impact on airflow through structure were performed. The results showed that the barn ventilation CFD model and simulations were in good agreement with the experimental measurements, predicting the airflow through the CBP barns structure for alternative roof ridge types adequately. The results also indicate that the best roof configuration in the winter was the open ridge with chimney for a west to east wind direction. [ABSTRACT FROM AUTHOR]

Simple Summary: This paper aims to validate a recently released commercial sensor (AFICollar®, Afimilk, Israel) to monitor dairy cows' feeding and ruminating behavior. In order to evaluate the sensor's performance under different feeding scenarios, the cows involved were divided into groups and fed different types of feed, including grazed pasture. Further, two version of the software used to convert raw data into behavioral information were tested and compared. Sensor data have been validated against visual observations, which served as the gold standard. Various statistical methods have been employed to assess sensor precision and accuracy. The results indicate that the sensor is adequately accurate for both feeding and ruminating time. However, the precision of the system appeared somewhat limited and should be improved. The use of sensor technologies to monitor cows' behavior is becoming commonplace in the context of dairy production. This study aimed at validating a commercial collar-based sensor system, the AFICollar® (Afimilk, Kibbutz Afikim, Israel), designed to monitor dairy cattle feeding and ruminating behavior. Additionally, the performances of two versions of the software for behavior classification, the current software AFIfarm® 5.4 and the updated version AFIfarm® 5.5, were compared. The study involved twenty Holstein-Friesian cows fitted with the collars. To evaluate the sensor performance under different feeding scenarios, the animals were divided into four groups and fed three different types of feed (total mixed ration, long hay, animals allowed to graze). Recordings of hourly rumination and feeding time produced by the sensor were compared with visual observation by scan sampling at 1 minute intervals using Spearman correlation, concordance correlation coefficient (CCC), Bland–Altman plots and linear mixed models for assessing the precision and accuracy of the system. The analyses confirmed that the updated software version V5.5 produced better detection performance than the current V5.4. The updated software version produced high correlations between visual observations and data recorded by the sensor for both feeding (r = 0.85, CCC = 0.86) and rumination (r = 0.83, CCC = 0.86). However, the limits of agreement for both behaviors remained quite wide (feeding: −19.60 min/h, 17.46 min/h; rumination: −15.80 min/h, 15.00 min/h). Type of feed did not produce significant effects on the agreement between visual observations and sensor recordings. Overall, the results indicate that the system can provide farmers with adequately accurate data on feeding and rumination time, and can be used to support herd management decisions. Despite all this, the precision of the system remained relatively limited, and should be improved with further developments in the classification algorithm. [ABSTRACT FROM AUTHOR]

Simple Summary: The bedding material used in dairy cow housing systems plays a key role in animal welfare and performance, since it influences the time that the animals remain lying down. The primary aim of this paper was to evaluate the physical properties of different bedding materials for dairy cattle and, further, to employ different fuzzy clustering algorithms to effectively cluster these alternative materials based on their physical properties. To perform nine physical analyses, 51 different bedding materials from various places in Europe were used. These data were analysed by principal components analysis (PCA) and then by fuzzy clustering analysis. Three clustering algorithms were tested for different numbers of clusters (2–8). They were compared by five validation indexes to choose the best clustering algorithm and the number of clusters. By these analyses it was possible to conclude that alternative materials can be classified based on their physical properties. The Gustafson–Kessel (GK) clustering algorithms, with eight clusters, fit better regarding the division of materials according to their properties. Posidonia oceanica showed potential to be used as an alternative bedding material due to its favourable physical properties. The bedding materials used in dairy cow housing systems are extremely important for animal welfare and performance. A wide range of materials can be used as bedding for dairy cattle, but their physical properties must be analysed to evaluate their potential. In the present study, the physical properties of various bedding materials for dairy cattle were investigated, and different fuzzy clustering algorithms were employed to cluster these materials based on their physical properties. A total of 51 different bedding materials from various places in Europe were collected and tested. Physical analyses were carried out for the following parameters: bulk density (BD), water holding capacity (WHC), air-filled porosity (AFP), global density (GD), container capacity (CC), total effective porosity (TEP), saturated humidity (SH), humidity (H), and average particle size (APS). These data were analysed by principal components analysis (PCA) to reduce the amount of data and, subsequently, by fuzzy clustering analysis. Three clustering algorithms were tested: k-means (KM), fuzzy c-means (FCM) and Gustafson–Kessel (GK) algorithms. Furthermore, different numbers of clusters (2−8) were evaluated and subsequently compared using five validation indexes. The GK clustering algorithm with eight clusters fit better regarding the division of materials according to their properties. From this clustering analysis, it was possible to understand how the physical properties of the bedding materials may influence their behaviour. Among the materials that fit better as bedding materials for dairy cows, Posidonia oceanica (Cluster 6) can be considered an alternative material. [ABSTRACT FROM AUTHOR]

Allowing dairy cattle to access pasture or outdoor areas is known to be beneficial for cows' welfare and is considered important by the general public. However, in confinement-based operations with high-yielding cows, pasture access may be difficult to implement, especially for lactating animals. Providing pasture access to heifers and dry cows seems a more feasible option for most farms. The objective of this study was to investigate the effects of providing high-yielding dairy cows with free-choice pasture access during the dry period on their health, behavior, and milk production. Over the study period, a total of 78 Holstein cows were assigned to 1 of 2 treatments during the dry period (51 ± 8 d): housing with free-choice access to the pasture (PAST) or housing continuously without any access to the outdoors (CTRL). After calving, all cows from both treatments were mixed and housed continuously. To assess the effects of the treatment on cows' performance, all animals enrolled were monitored both before calving and during the first 100 d in milk of the following lactation. The behavior of all cows involved was monitored continuously during the whole observation period using collar-based sensors. All cows were inspected monthly to assess lameness, hock lesions, cleanliness, and body condition score. During the period after calving (0–100 d in milk), milk production and composition were also monitored. Results showed that free-choice pasture access affected cows' feeding behavior. Before calving, the animals in PAST spent more time feeding than in CTRL and, interestingly, this difference tended to persist for several weeks after calving. During the dry period, cows in PAST were cleaner than in CTRL but no differences in locomotion and body condition score were found between the 2 groups. Free-choice pasture access during the dry period also affected milk production during the following lactation. The cows that spent the dry period in PAST produced more milk than CTRL counterparts, particularly for the animals that calved during summer. In the current study we have found that providing free-choice pasture access during the dry period can positively affect the performance of dairy cattle and represents a desirable practice in confinement-based dairy production systems. [ABSTRACT FROM AUTHOR]

Manure management is a crucial aspect warranting attention since a significant proportion of anthropogenic NH 3 emissions are derived from it. In dairy cattle, only 20 to 30% of the dietary N is retained in milk, while a relevant amount is excreted in urine and faeces. A substantial proportion (60 to 80%) of the urine-N of high-producing dairy cows exists as urea, which is rapidly converted to NH 4 + by the urease enzyme, and volatilizes into the atmosphere as NH 3. While extensive literature studied the effects of technical solutions for cattle housing and waste storage, environmental parameters and manure treatments on NH 3 emission, limited information exists on its quantification under controlled conditions from isolated and mixed excreta. The aim of the study was to evaluate the NH 3 emission reduction potential from maintaining urine and faeces separate in dairy farming systems. NH 3 emissions from urine (U) and faeces (F) alone, as well as their mixture (M) were monitored under different environmental conditions (10 °C and 20 °C) and different exposure periods (24 and 72 h). The M samples had significantly higher NH 3 emissions (about 100 times higher) than U and F, both in cold and warm conditions and at all exposure periods. Significantly higher NH 3 emissions were measured from U, compared to F, after 48/72 h of exposure, probably linked to the higher pH and water content found in U. Separating urine and faeces (before contact) has the potential to reduce NH 3 emissions by about 99% during the first 24–72 h of air exposure in dairy cow management systems. This potential approach should also be coupled with accurate urine management, under conditions that prevent environmental urease contamination. Such strategy could also be an effective solution to improve on-farm N reuse and to reduce the adoption of chemical fertilizers. [Display omitted] • NH 3 emissions from dairy cattle excreta were monitored using a dynamic chamber. • Faeces, urine and the mix of them were monitored at different exposure period. • NH 3 emissions from the mix are almost 100 times higher than faeces and urine alone. • Separation of dairy cattle excreta is an effective strategy to cut NH 3 emissions. • Warm conditions promote NH 3 emissions. [ABSTRACT FROM AUTHOR]

The bedding material used in barns for dairy cows has a significant effect on animal welfare and performance. Bedding influences the duration in which animals remain lying down and, consequently, the processes of rumination and milk production. It is crucial to have a complete understanding of the properties of bedding materials and the effects of alternative bedding materials on dairy cattle. This paper aims to evaluate the physical, chemical, and biological properties of various alternative and conventional bedding materials for dairy cattle for use in compost bedded pack or freestall barn systems. We analyzed 50 samples of 17 bedding materials produced in 3 European countries. We analyzed physical properties including the water holding capacity, porosity, moisture content, bulk density, dry bulk density, and particle size. Chemical analyses were performed to determine the total N, total organic C, and C:N ratio. In the biological analyses, the Escherichia coli count, total bacteria count, coliform count, and Klebsiella spp. count were assessed. The results demonstrated how the physical properties of the bedding materials may influence the chemical and biological properties. All of the materials presented adequate chemical properties to be used as bedding material. The physical properties of the bedding materials differed widely among the materials except for the dry bulk density, which presented no difference. Moreover, the contamination of each studied microorganism was observed for each bedding material to determine which material had the lowest level of contamination. Posidonia oceanica, Miscanthus grass, and spelt husks could be considered as a potential alternative material for use as bedding material for dairy cows in both systems (i.e., composted bedded pack and freestall). This experiment illustrated the importance of performing thorough physical, chemical, and biological analyses before implementing a material as bedding for dairy cattle. [ABSTRACT FROM AUTHOR]

This research aimed to characterize, evaluate and compare the spatial distribution of the leading bed variables, animal welfare indicators, and milk production in a closed compost-bedded pack barn (CBP) with a negative tunnel ventilation system, for summer and winter periods. The study was carried out in a CBP located in the Zona da Mata region, Minas Gerais, Brazil. The geostatistical modeling technique evaluated the variables of temperature, moisture content, and pH (on the surface and depth of 0.20m) across the length of the bed. Bed samples were characterized for carbon (C), nitrogen (N), and C:N ratio. Cows housed in the CBP were assessed for locomotion and hygiene scores and average milk production. To evaluate the thermoregulation of the cows, the respiratory rate (RR) and surface temperature (ST) were measured. Geostatistical analysis showed spatial dependence and the non-uniformity of the spatial distribution of bed variables. The worst levels of bed temperature and moisture were found in the regions close to the evaporative cooling plate, surrounding the feeding alley, and in the region with the highest cow stocking. The C:N ratio, obtained in both climatic seasons of the year, remained outside the recommended range for ideal composting. During the summer and winter, the bed variables' values suggest that the material was below levels for optimal composting; however, the aerated inner layer was biologically active. The high animal density significantly impacted the worsening of the bed moisture content and internal temperature. In general, dairy cows showed adequate hygiene (score of 1 and 2) and locomotion (score of 0 and 1) scores for the two climatic seasons evaluated, indicating good welfare conditions. In relation to RR and ST, the summer period presented less favorable environmental conditions. During winter, the average milk production was 28.1 ± 7.2 kg day-1, and during summer, it was 26.9 ± 6.7 kg day-1. • The use of geostatistics made possible to assess the quality of the CBP bed. • The high cow stocking density had an impact on the worsening of the moisture content and internal temperature in the bed. • Dairy cows showed a good hygiene and locomotion scores in the CBP. • In the closed CBP system average milk production was slightly lower during the summer in comparison with winter. • The use of infrared thermography made possible to evaluate the surface temperatures of in cows and bed in closed CBP. [ABSTRACT FROM AUTHOR]