53 research outputs found
Thermal comfort assessment in a typological non-isolated maternity pig sheds with different types of farrowing systems
Received: February 1st, 2021 ; Accepted: May 8th, 2021 ; Published: May 19th, 2021 ; Correspondence: [email protected] facilities in tropical climates, especially the maternity, have worked with
typological systems that have been little studied to determine the influence of the type of
farrowing on microenvironmental conditions and its effect on both the sows and the piglets'
physiological parameters. Therefore, the aim of the research was evaluate the thermal
environment (Temperature Humidity Index - THI and Radiant Thermal Load - RTL) and its
influence on some physiological parameters (respiratory frequency - RF and rectal temperature -
TRectal) in the sows and piglets in two different types of farrowing systems (Traditional and
Slatted), in a typological swine facility located in tropical climates in Colombia. The findings
showed that in the two systems, both for sows and piglets, the type of farrowing system did not
generate significant differences in the physiological responses RF and TRectal. Also, the RTL
did not show significant differences in the two types of farrowing system at the piglets and the
sows’ level, without exceeding the maximum allowed levels. Temperature-Humidity Index was
above the threshold during all experimental time, being slightly higher at the piglets' level with
Slatted systems. These results show that the type of floor has little impact on the conditions of
animal thermal comfort at the sows and piglets’ level. However, variables like low-temperature,
low radiant energy exchange, and high humidity, which were found mainly at the piglets’ level,
could have the highest incidence for not achieving a suitable microenvironment. This means that
almost all Colombian pig farming facilities require a redesign of their farrowing system to
guarantee better thermal conditions for both piglets and sows
Airflow profile study of a compost dairy barn using a low-cost 3D-printed anemometer network
Mechanical ventilation is commonly used for environmental thermal regulation inside
closed-field agricultural production systems. Analyzing the air distribution inside these facilities
and the correct operation of the fans can be a challenging. This could be determined using cost
prohibitive techniques as particle image velocimetry or deploying large wind sensors networks
on-site. To avoid this limitation without a lack of measurement accuracy, this research was
focused on developing and test a low-cost anemometer network based in low cost propeller’s
anemometers, built using fused 3D-printed and open-hardware platforms. Four propeller
anemometers with three to six blades were simulated using the 6-DOF method of ANSYS
computer fluid dynamics software. Similar results were obtained for all the simulated models
with minor differences. Anemometers were tested in an open circuit wind tunnel before to be
evaluated in two open compost dairy barn building using high-volume low-speed and low-volume
high-speed fans. Data were analyzed by employing contour maps, descriptive statistics and
correlation. The results show that the anemometer network determines the fan’s wind profile for
wind speeds over 0.7 m s-1
and it was possible to determine the facilities spots with ventilation
problems. The proposed anemometer network and methodology are a good alternative to analyze
the operating conditions of the tested agricultural facilities and optimize its performance
Assessment of a low-cost solar water heating systems in farrowing facilities
ArticleThe objective of this study was to develop a prototype solar heater using alternative materials and then to compare its thermal efficiency against that of two other commercial solar heating systems when heating the floor of piglet housing. To evaluate the thermal heaters, temperature sensors were installed in the inlet and outlet of each floor and the thermal reservoir. The results showed good performance, however the thermal efficiency of the alternative heater was lower than the conventional systems. However, due to the construction of this solar collector with alternative materials its cost was relatively low and its operation is easier than the other conventional heater, therefore this heater is a good alternative to use for small livestock producer
Compost-bedded pack barns in the state of Minas Gerais: architectural and technological characterization
ArticleCompost 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 and aeration using
mechanical tillage. The average bedding moisture content was found to be 36.9 ± 5.2% (w.b.).
Based on the information found, it is possible to evaluate that there is still no defined construction
pattern, with a high variation of size and technologies employed
Spatial distribution of thermal variables, acoustics and lighting in compost dairy barn with climate control system
ArticleThe 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
Comparison of airflow homogeneity in Compost Dairy Barns with different ventilation systems using the CFD model
In the pursuit of high milk productivity, producers are using confinement systems in
order to improve performance and animal welfare. Among the housing systems, the Compost
bedded-pack barns (CBP) stand out. In these barns a bedding area is provided inside, where cows
move freely. Generally this area is covered with carbon source material (such as sawdust or fine
dry wood shavings) which together with manure, thanks a regular mechanically stirring, ensures
the aerobic composting process. The ventilation in these facilities has the function of
dehumidifying the air, improving the air quality, drying the bedding, improving the thermal
comfort conditions of the confined animals. This work aimed at validating a computational model
using Computational Fluid Dynamics (CFD) to determine the best homogeneity of airflows
generated by different forced ventilation systems used in CBP barns. Two CBP barns were
compared with different ventilation systems: high volume low speed (HVLS) and low volume
high-speed (LVHS) fans. The results showed that the proposed model was satisfactory to predict
the flows generated by both types of fans. It was concluded that the use of HVLS fans produced
a more homogeneous airflow when compared to LVHS fans. The use of mechanical ventilation
in tropical conditions is necessary for the proper functioning of the system. In this study, the
systems used promoted the increase in air speed to levels close to adequate
Estimate of manure present in compost dairy barn systems for sizing of manure storage
Milk production is increasingly modernized as a result of the growing demand for food
around the world. Improvements in livestock facilities are observed, with a large increase in the
use of feedlot systems such as the Compost Dairy Barn. Increasing milk production in
confinement systems has also raised concerns such as the management of wastes (water, faeces
and urine) from the system, which has become one of the most important issues in the intensive
dairy farms. The aim of this work was to estimate the amount of manure present in compost dairy
barn systems in order to size the manure storage. The study was conducted at four compost dairy
barns in southern Minas Gerais, Brazil. These compost barns had different bedding materials and
dimensions. In each farm, data on milk yield and quality (daily production, fat and protein
content), animal weight and amount of feed ingested by the animals were collected. Total-day
manure delivered by the cows in the feeding alley and milking parlour was piled up together and
weighed. Based on the results, it was observed that, in the compost dairy barns, only part of the
total manure produced per day was delivered in the milking parlour (1.6 and 2.0%) and in the
feed alley (27.6 to 49.3%). These results are very important for designers for the proper manure
management system design of the dairy farms
Analysis of environmental conditions in two different Compost Bedded Pack Barn systems for dairy cattle
Received: February 1st, 2023 ; Accepted: April 27th, 2023 ; Published: May 10th, 2023 ; Correspondence: [email protected], [email protected] objective of this study was to analyse and compare the thermal environment of
dairy cattle facilities in an open compost bedded pack barn (CBP) with natural ventilation and
closed CBP (without thermal insulation) and climate control system. The research was conducted
in a property located in Zona da Mata, Minas Gerais, Brazil. During the summer and for different
periods of the day, the following average environmental variables observed inside the facilities
were measured: dry bulb temperature, relative humidity and Temperature and Humidity Index
(THI). The results were submitted to an analysis of variance to determine the significance of the
variables in the different treatments. It was found that the closed and climate control system CBP
promoted greater control of the facility's internal microclimate, registering smaller thermal
amplitudes and a greater reduction in the animals' exposure time to stressful thermal conditions,
compared to the CBP with natural ventilation. However, during summer afternoons, comfort
indices indicated moderate stress. It is concluded that the closed CBP, regarding the analysed
variables, indicated potential use, provided that a careful study of the climate of the region is
carried out before implementation, the factors related to the ambient conditioning and better
insulation of the construction are adjusted. The climatic variables inside the open CBP indicated
a high stress condition for the animals, suggesting the placement of positive pressure fans and
sprinklers properly distributed in the feed alley, to guarantee benefits to the entire area of the
animal housing
Compost barn system and its influence on the environment, comfort and welfare of dairy cattle
Received: January 16th, 2023 ; Accepted: April 27th, 2023 ; Published: May 15th, 2023 ; Correspondence: [email protected] aim of this study was to evaluate the effect of the thermal environment on
behavioral and physiological parameters of crossbred cows of different productivity levels
confined in a compost barn system. For this, air temperature (Tdb) and relative humidity (RH)
data were measured using sensors/registers and wind speed (Vair) was recorded with the aid of
an anemometer. Subsequently, these data were used to calculate the Temperature and Humidity
Index (THI). Bedding material variables (pH and humidity) were also evaluated. The animals
were evaluated for physiological variables (respiratory rate – RR and surface temperature – ST),
scores (body condition, locomotion and dirt) and behavior. The analyses were carried out on two
groups of cows (Group 1: high production vs. Group 2: medium and low production). The average
pH of the bedding material was 8.5, within the recommended range. In the case of the
physiological responses of the cows, the respiratory rate (RR) of Group 1 indicated better
conditions of thermal comfort in the morning vs. the afternoon. The system was efficient in both
groups based on body condition score, indicating favorable conditions for the health of the
animals. Regarding the behavioral evaluation, Group 1 and 2 were statistically similar and had
the longest rumination times, in relation to the other evaluated behaviors. Regarding active
periods, medium production were the most active. Regarding idle time, low production spent
more time idle than the other animals
Comparison between the thermal properties of cement composites using infrared thermal images
The use of agribusiness residual lignocellulosic fibres can be a good alternative in the
development of lignocellulosic composites. The current work aimed to investigate the thermal
performance of cement-based composites with lignocellulosic materials: Eucalyptus, sugarcane
bagasse, coconut fibre in comparison with commercial gypsum board to be used as internal
partitions of the building using infrared thermal images. Three repetitions for each kind of
lignocellulosic material were made, and three commercial gypsum boards were used. In the
production of the panels, the following parameters were applied: material and cement ratio,
1:2.75; water and cement ratio, 1:2.5; hydration water rate of 0.25; additive, 4% (based on cement
mass). The calculations were performed for a nominal panel density of 1,200 kg m-
Âł. The thermal
analysis was performed in a chamber composed of MDP (Medium-Density Particleboard) and
with an internal layer of rock wool and the heat source (thermal resistance). For the superficial
temperature measurement, a FLIR E75 camera was used to capture the infrared images. When
the internal temperature of the chamber stabilized at 50 °C, an infrared thermal image was
collected from each side of the composite. Thermal properties were analysed: thermal
conductivity, resistivity, resistance, and transmittance. Based on the results, sugar cane cement
composites were characterized by higher values of thermal conductivity. Related to thermal
resistivity, thermal resistance, and thermal transmittance, only the coconut panel presented
similar behaviour to the commercial gypsum board. Thus, cement composite using coconut can
be a potential alternative that might solve energy and environmental concerns simultaneously
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