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In this study, we aimed to assess the spatial variability of microclimate inside a closed compost-bedded pack barn (CBP) with a negative ventilation system during summer and winter. The research was carried out in a CBP located in the Zona da Mata region, Minas Gerais, Brazil. For each of the stations analyzed, the following environmental mean variables observed inside a CBP were measured: air dry-bulb temperature (tdb), air relative humidity (RH), and windspeed, Temperature-Humidity index, and specific enthalpy. The kriging maps showed that the most critical housing conditions in the thermal environment were found, mainly, from the central part of the CBP, close to the exhaust fans. The analyses also pointed out that the system presented temperature gradients along the length, up to 3°C. During the summer afternoon, the entire region of the CBP was in a discomfort situation (tdb>26°C; RH>75%). During the winter, the measured environmental data remained within the comfort zone throughout the facility. However, probably due to the lack of thermal insulation of the material used to close the sides of the CBP, it did not allow spatial thermal uniformity for both seasons. It was also inefficient to keep the animals within the comfort zone for lactating cattle during the critical summer period.

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 ., (Copyright © 2021. Published by Elsevier Ltd.)

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]

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]

In this study, we performed a systematic review to assess the effect of thermal stress on the behavior of lactating cows housed in compost barns. Peer-reviewed articles written in English that evaluated the effect of heat stress on the behavior of lactating cows raised in compost barns were used in this systematic review. The resulting articles (38) underwent a four-step PRISMA appraisal process and resulted in six articles that fitted our inclusion criteria. Our review highlighted that the temperature and humidity index prevailed among the studies to evaluate thermal comfort. Regarding the behavior, heat stress promoted decreases in feed events and the time that cows spent lying down. In contrast, there was an increase in events of visiting the water trough, the number of steps, agonistic behavior, and dyspnea. In conclusion, heat stress affected the behavior of lactating cows raised in compost barns; however, some care is needed in extrapolating our findings since this is a recent research area and further studies are needed. [ABSTRACT FROM AUTHOR]

Simple Summary: Here, we aimed to characterize the structural features, to descript the bedding material, and to observe the management practices of compost (CBP) barns in the state of Kentucky (USA). These systems allow thermal comfort for animals, as well as better hygiene conditions for cows. All CBP barns showed structural variations. Sawdust and wood shavings were the most used materials in beds and coliforms E. coli, Bacillus, and Streptococcus were present in the CBP barns with a lower moisture content. In addition, the most frequently cited benefits of the CBP barn include increased cow comfort compared to free stalls; increased cow cleanliness; low maintenance; its ability to work well for heifers and lame, fresh, problem, and old cows; and its ability to allow natural resting positions with no free stalls. This study was conducted to describe the building layout and dimensions, characterize the bedding material, and observe the management practices in 42 compost-bedded pack (CBP) barns in Kentucky (USA). The average herd size found in the study was 90 cows and the breeds consisted of Jersey (6.8%), Holstein (72.7%), and mixed (20.5%). The average CBP barn dimensions were 49.1 m (length) by 21.9 m (width). Many of these barns had feed alleys and driveways; overshot ridges with frequent orientation from NE to SW; and green sawdust, kiln-dried sawdust, or a mixture of both as the most common bedding materials. The bed-turning process was performed mechanically at depths of less than 0.25 m, and the loading of fresh material was performed every one to five weeks, varying by season, weather conditions, barn size, and cow density. The average bedding moisture content was found to be 59.0% (wet bulb—w.b.) and ranged from 36.2 to 71.8%. Coliforms were not present in barns that had a higher compost temperature, and the E. coli, Bacillus, and Streptococcus counts were higher in the barns that had a lower moisture content. In conclusion, it was observed that heterogeneous management was used among the barns and that the producers were satisfied with the compost barn system. [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]

Featured Application: The findings are highly relevant for the design and management of bedded pack barns. 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 properties utilizing sawdust in CBP barns is of environmental and economic relevance. In this paper, the aim was to (a) develop predictive equations for the thermal conductivity (k) of compost bedding as a function of moisture content (MC), the degree of compaction (DCo), and particle size (PS); and (b) investigate the links between k and depth within bedding material. Samples of compost bedding materials were collected from 42 commercial CBP barns distributed throughout Kentucky (USA). From these predictive equations, it was possible to understand how the MC, DCo, and PS of the bedding materials may influence the behavior of k. These results are very useful for solving obstacles to simulate and predict the variable outcomes of the compost bedding materials process in CBP barns, allowing for its optimization, consequently reducing the time and energy spent on their optimization and allowing for simulation and assessment of compost bedding process modifications. The results of the current study may have important implications in the design and management of bedded pack barns. [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]

Packaging waste is cause for serious concern. Each year hundreds of millions of tons of packaging are produced, therefore solutions that drastically reduce their environmental impact are urgently needed. While the recycling of metal, wood, paper and cardboard packaging has been significantly improved, an efficient recycling or disposal of some plastics is not yet feasible. The European Union implemented various regulations concerning packaging and packaging waste and set some relevant short to medium-term targets for recycling and disposal rates. Over the last decade, the global trend of the eco-sustainable packaging market is heading in the same direction. The aim of this research is to develop an innovative and sustainable composite material for the production of tertiary packaging based on the combination of natural fibres and biodegradable biopolymers. In particular, the experimental application entailed the creation of prototypes consisting of a material made of straw and biodegradable plastic Mater-Bi® which is named NeoPalea. The new material was prototyped to verify its physical characteristics and to determine its potential use to replace current not-biodegradable packaging. The results show a good match with the characteristics of current polymers, suggesting that this material can be used as a potential substitute in packaging applications. [ABSTRACT FROM AUTHOR]

Compost-bedded pack barns (CBPB), generally known as compost dairy barns, are alternative housing systems for dairy cows. In these barns, the whole surface of the resting area is covered with a deepbedded pack that is frequently stirred in order to incorporate fresh manure into the pack and to enhance the evaporation of water. Experiences with CBPB for dairy cows are reported in literature from the US, Israel, the Netherlands and Austria. Potential advantages of these housing systems regard animal welfare and manure management. Since 2006, this housing system has been widely applied in Italy. However, there is still little scientific knowledge available about Italian CBPB. This study aims to describe the housing system, assess producers' satisfaction and measure performance of dairy cows housed in CBPB. Ten commercial dairy farms in northern Italy were involved in the study. All pens in each farm were surveyed to determine the total available surface area, bedded area and pack depth. A questionnaire was submitted to each farm manager in order to investigate management practices, labour requirement, amount of bedding materials used and producers' satisfaction. The temperature of the bedded pack was measured in summer and in winter. Data from the Italian Dairy Association were collected for each herd over a period of one year (from September 2011 to September 2012). In the barns involved in the study, the average total available area was 10.9 m2/cow and the average pack area was 6.7 m²/cow. The bedded pack was aerated 1.4 times per day. The most commonly used bedding material in these farms was dry sawdust. The consumption of bedding materials was 8.1 m³/cow per year. A tendency towards inverse correlation was found between the space per cow and the amount of bedding needed per cow (R²=0.395; P=0.051). Operations related to pack management required 4.1 hours of labour per cow per year. A direct relationship was found between the bedded area space per cow and the annual labour required for pack management (R²=0.505; P=0.048). Although some concerns were raised about the cost of bedding and ease of management, producers were satisfied with this housing system. [ABSTRACT FROM AUTHOR]