Assessment of spatial variability of bedding variables in compost bedded pack barns with climate control system (original) (raw)
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Animals
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 s...
Anais Da Academia Brasileira De Ciencias, 2023
In Compost-Bedded Pack Barn (CBP) systems, air velocity is linked with the thermal comfort of housed dairy cattle and bedding quality and, therefore, assessing ventilation efficiency is essential. In this context, the objective of this study was to evaluate and characterize dependence and spatial distribution of air velocity at the 1.5 m height (v air,M) and at bedding level (v air,B) in an open CBP system with positive pressure ventilation. The study was conducted in 2021, in a facility located in the Zona da Mata region, Minas Gerais, Brazil. The facility area was divided into a mesh composed of 55 equidistant points, where v air,M and v air,B data were collected in the morning (09:00 a.m.) and afternoon (03:00 p.m.) periods, during three weeks in Brazilian winter. Geostatistics techniques were used to assess dependence and spatial distribution. In both periods evaluated, there were a strong occurrence of spatial dependence and non-uniform v air,M and v air,B distributions. The v air,M and v air,B values were lower than recommended (1.8 m•s-1) in more than 65.0% of the area. Adequate ventilation levels were observed only in the first 20.0 m of the facility, from Southeast to Northwest, because of the fan lines present.
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, condition...
Agronomy Research, 2019
The objective of this work was to evaluate the spatial distribution of thermal conditions and bed variables in compost dairy barns with different ventilation systems, through the technique of geostatistics. The experiment was conducted in April 2017, in farms located in Madre de Deus, Minas Gerais, Brazil. Three facilities were evaluated with different ventilation systems: natural (NV); mechanical of low volume and high speed (LVHS); and mechanical of high volume and low speed (HVLS). The interior of the premises was divided into 40 meshes equidistant points, in which air temperature, relative humidity and air speed were manually collected. Geostatistics technique was used to assess the spatial dependence of the variables. The results showed the occurrence of dependence and spatial variability of the variables evaluated. Based on thermal comfort indexes, it was concluded that dairy cows were under stress conditions during the hottest hours of the day in the three animal facilities e...
2019
The main objective of this research was to evaluate the spatial distribution of the thermal variables, acoustics and lighting in climate controlled compost dairy barn. The experiment was conducted in October 2017, in a farm located in the west of Minas Gerais state, Brazil. For the study, the interior of the animal facility was divided into 120 meshes equidistant points, in which air temperature (tdb), relative humidity (RH), noise, illuminance, and air speed (Vair) were manually collected. The technique of geostatistics was used to evaluate the distribution and spatial dependence of variables. Spatial distribution maps showed the occurrence of high variability of attributes and content within the animal facility. Thermal environment variables showed alert situations throughout practically the entire facility. The noise and luminance levels were within the recommended values.
2019
Compost bedding pack (CBP) barns have been receiving increased attention as an alternative housing system for dairy cattle. Thus, a systematic investigation of the primary management practices of dairy cattle in CBP barns in the state of Minas Gerais (Brazil) has proven to be of environmental and economic relevance. The aim of this research was to summarize the compost bed data, barn dimension data and to determine the major interactive factors in the success of bed composting from qualitative and quantitative methods. Data for this study was collected from 16 CBP barns, distributed throughout the southern state of Minas Gerais (Brazil) between March 2017 and July 2018. These data were used to describe the building layouts and dimensions, to identify barn management practices, and to characterize the compost bedding material concerning moisture content. The majority of these barns had feed alleys and driveways; overshot ridges with frequent orientation from NE to SW; bedding process...
Journal of Dairy Science
The aim of this study was to determine the effect of housing system (or manure management system) and season on manure N recovery and volatilization using an N mass balance. Dietary, milk, and manure N were monitored together with outside temperatures in 6 dairy barns. Three barns were designed as conventional freestalls (cubicle, CUB) with an automatic manure scraper system and concrete floor, in which the gutter in the middle was continuously scraped (every 2-4 h) and the slurry was conveyed toward an open-air concrete pool. The other 3 barns were designed as a loose housing system (HS) with a compost-bedded pack (CB) and conventional confinement housing provided with a feed alley that was cleaned mechanically (2-3 times per day). The farms under study were located near Lleida in the center of the Ebro valley, in northeastern Spain. Nitrogen recovery was measured twice under farm-like conditions either during spring-summer (3 mo of increasing temperatures) or fall-winter (3 mo of decreasing temperatures). The number of cows per barn ranged from 99 to 473, and average age, mean lactation, and parturition intervals were 4.1 yr, 2.43 lactations, and 426.6 d, respectively. In spring-summer, animals ate more [26.3 vs. 23.8 kg of dry matter (DM)/d] and produced more milk (34.6 vs. 31.3 kg/d ± 0.68). However, milk composition did not change. Stored manure from the CB system showed a higher DM concentration with respect to the CUB system (379.15 vs. 97.65 g/kg of fresh matter); however, N (31.45 vs. 40.2), NH 3-N (5.3 vs. 18.9) and its ratios with phosphorus (NH 3-N:P, 3.52 vs. 5.2) and potassium (NH 3-N:K, 0.615 vs. 2.69) showed the opposite trend. No differences were found in N intake (653 vs. 629.5 g/d) or milk N secretion (190 vs. 177.8 g/d for CUB and CB barns, respectively) although net N recovery of the excreted N (N intake − N Milk) was significantly lower in manure in CB barns than in CUB systems (193.8 vs. 389.3 g/d). The proportion of N irreversible loss in relation to the N intake was higher in CB than in CUB barns (42.3 vs. 11.0%). There was no clear association between season and irreversible N losses; however, the housing system was pivotal in the association between N recovery in manure and irreversible losses by volatilization.
2021
This work classifies the dairy farms that use compost barns (CB) as a feedlot system for dairy cows in the Brazilian subtropical region, in terms of farm structure, constructive aspects, environmental and compost bedded pack characteristics, and reports the variability among the dairy farms that adopted it. Additionally, this research identifies structural and management factors that interfere in the compost bedded pack quality. The data were obtained in loco , with facilities measurements, herd observations and collection of technical information, in 30 dairy farms. The clustering analysis, based on 12 variables, resulted in the formation of three groups: conventional and adapted CB (n=18, with new and adapted facilities, of different sizes, full time using, with adequate pack characteristics or not), large conventional CB (n = 6, larger barns, more similar to American models, full time using) and, partial use CB (n = 6, used in hot hours of the day or rainy season, with better pac...
Applied Sciences
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...