scholarly journals Solar Radiation Limits the Use of Paddocks by Laying Hens Raised in the Free-range System

2021 ◽  
Author(s):  
Evandro Menezes de Oliveira ◽  
Larissa Queiroz Medeiros De Oliveira ◽  
João Victor Do Nascimento Mós ◽  
Bruno Emanoel Teixeira ◽  
Sheila Tavares Nascimento
Keyword(s):  
Solar Radiation ◽  
Laying Hens ◽  
High Amplitude ◽  
Heat Gain ◽  
Free Range ◽  
Behavioural Analysis ◽  
Frequency Of Use ◽  
Production Animals ◽  
Indoor And Outdoor ◽  
Main Factor

Abstract Laying hens on the Free-range systems are susceptible to challenging situations in relation to the rearing environment. Therefore, this work evaluated how solar radiation influences the behaviour of laying hens raised in a Free-range system, in the Brazilian Savanna. The activities included data collection of meteorological variables and behavioural analysis of three-hundred commercial laying hens in relation to the frequency of use of indoor and outdoor areas of rearing housing. The solar radiation is the main factor that directly affects the heat gain of production animals, in this experiment had a high amplitude during all day, going from 33.42 W m-2, to 756.98 W m-2. It was observed that the highest frequency of 79% and 91% use of the barn areas by the hens was at 8am and 4pm, respectively. The internal area of the housing was more used by hens 87% and 68% at 12h and 14h, respectively. Hens were not observed in the paddocks at noon and 2 pm. Hens spend more than 6 hours of the day inside the housing to provide shelter from solar radiation. Which the conclusion the solar radiation influences the behaviour of laying hens, at times of the day of the higher incidence of radiation, and high air and global temperatures, it was not observed the presence of hens in the external areas of the housing, especially with the use of the paddocks, at these times the hens seek shelter inside the housing to get away from the incidence of direct solar radiation.

Effects of solar radiation and wind speed on metabolic heat production by two mammals with contrasting coat colours.

1995 ◽  
Vol 198 (7) ◽  
pp. 1499-1507 ◽  
Author(s):  
G E Walsberg ◽  
B O Wolf
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Heat Production ◽  
Metabolic Heat Production ◽  
Heat Gain ◽  
Solar Heat ◽  
Wind Speeds ◽  
Convective Heat Loss ◽  
Metabolic Heat ◽  
Solar Heat Gain

We report the first empirical data describing the interactive effects of simultaneous changes in irradiance and convection on energy expenditure by live mammals. Whole-animal rates of solar heat gain and convective heat loss were measured for representatives of two ground squirrel species, Spermophilus lateralis and Spermophilus saturatus, that contrast in coloration. Radiative heat gain was quantified as the decrease in metabolic heat production caused by the animal's exposure to simulated solar radiation. Changes in convective heat loss were quantified as the variation in metabolic heat production caused by changes in wind speed. For both species, exposure to 780 W m-2 of simulated solar radiation significantly reduced metabolic heat production at all wind speeds measured. Reductions were greatest at lower wind speeds, reaching 42% in S. lateralis and 29% in S. saturatus. Solar heat gain, expressed per unit body surface area, did not differ significantly between the two species. This heat gain equalled 14-21% of the radiant energy intercepted by S. lateralis and 18-22% of that intercepted by S. saturatus. Body resistance, an index of animal insulation, declined by only 10% in S. saturatus and 13% in S. lateralis as wind speed increased from 0.5 to 4.0 ms-1. These data demonstrate that solar heat gain can be essentially constant, despite marked differences in animal coloration, and that variable exposure to wind and sunlight can have important consequences for both thermoregulatory stress experienced by animals and their patterns of energy allocation.

scholarly journals Early rearing enrichments influenced nest use and egg quality in free-range laying hens

animal ◽  
2020 ◽  
Vol 14 (6) ◽  
pp. 1249-1257 ◽  
Author(s):  
M.S. Bari ◽  
A.M. Cohen-Barnhouse ◽  
D.L.M. Campbell
Keyword(s):  
Laying Hens ◽  
Egg Quality ◽  
Free Range ◽  
Early Rearing

scholarly journals Study on the improvement of indoor hot and humid environment in Tibetan-style residential areas in northwest Sichuan

2020 ◽  
Vol 165 ◽  
pp. 04074
Author(s):  
Sun Yidan
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Wall Temperature ◽  
Thermal Environment ◽  
Cold Weather ◽  
Living Room ◽  
Residential Areas ◽  
The West ◽  
Solar Radiation Intensity ◽  
Indoor And Outdoor

Indoor and outdoor thermal environment is under a definite impact on the human body, and to a large extent affects the comfort of people living. In this paper, the indoor and outdoor thermal and humidity parameters of Dongma village in the west of Sichuan Province were measured. On the living room and bedroom hot and humid comfort survey, the outside wall temperature and the local climate to do analysis, get January Dongma village typical residential indoor humidity environment, including the temperature of the living room is 6.6~19.5°C, the relative humidity is 28.9~45.3%rH, the bedroom temperature is 3.5~19.8°C, the relative humidity is 35.7~52.8%rH, the outdoor temperature is 2.4~27.4°C, the temperature in the east is -11.1~-3.3°C, -3.9~11.2°C at the west, -8~2.8°C at the south, -10.4~-2.5 °C at the north, 1.6~29.2 °C at the roof, and the solar radiation intensity is 422~739W/m^2. Combined with the above data, it is found that the overall insulation performance of the wall is good, but by the influence of the cold weather outside, the indoor temperature is still low, it is difficult to respond to the comfort needs of residents. The wall temperature is altered due to solar radiation. In view of the current situation of the indoor thermal environment in Dongma village, a series of optimization suggestions are submitted at the end of the paper.

Flock use of the range is associated with the use of different components of a multi-tier aviary system in commercial free-range laying hens

2019 ◽  
Vol 61 (2) ◽  
pp. 97-106 ◽  
Author(s):  
T. Z. Sibanda ◽  
S. W. Walkden-Brown ◽  
M. Kolakshyapati ◽  
B. Dawson ◽  
D. Schneider ◽  
...  
Keyword(s):  
Laying Hens ◽  
Free Range
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