scholarly journals Thermal environment characterization of laying hen-housing systems

2022 ◽  
Vol 10 (1) ◽  
pp. 1-9
Author(s):  
Nágela Maria Henrique Mascarenhas ◽  
Dermeval Araújo Furtado ◽  
Bonifácio Benício de Souza ◽  
Airton Gonçalves de Oliveira ◽  
Antonio Nelson Lima da Costa ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cynthia Schuck-Paim ◽  
Elsa Negro-Calduch ◽  
Wladimir J. Alonso

AbstractSocietal concern with the welfare of egg laying hens housed in conventional cages is fostering a transition towards cage-free systems in many countries. However, although cage-free facilities enable hens to move freely and express natural behaviours, concerns have also been raised over the possibility that cage-free flocks experience higher mortality, potentially compromising some aspects of their welfare. To investigate this possibility, we conducted a large meta-analysis of laying hen mortality in conventional cages, furnished cages and cage-free aviaries using data from 6040 commercial flocks and 176 million hens from 16 countries. We show that except for conventional cages, mortality gradually drops as experience with each system builds up: since 2000, each year of experience with cage-free aviaries was associated with a 0.35–0.65% average drop in cumulative mortality, with no differences in mortality between caged and cage-free systems in more recent years. As management knowledge evolves and genetics are optimized, new producers transitioning to cage-free housing may experience even faster rates of decline. Our results speak against the notion that mortality is inherently higher in cage-free production and illustrate the importance of considering the degree of maturity of production systems in any investigations of farm animal health, behaviour and welfare.


PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e110076 ◽  
Author(s):  
Petra Videnska ◽  
Md. Masudur Rahman ◽  
Marcela Faldynova ◽  
Vladimir Babak ◽  
Marta Elsheimer Matulova ◽  
...  

2007 ◽  
Vol 4 (4) ◽  
pp. 145-154
Author(s):  
Kin F. Man ◽  
Alan R. Hoffman

NASA's Mars Exploration Rover (MER) project involved delivering two mobile science laboratories (rovers) on the surface of Mars to remotely conduct geologic investigations, including characterization of a diversity of rocks and soils. The rovers were launched separately in 2003 and have been in operation on the surface of Mars since January 2004. The rovers underwent a comprehensive pre-launch environmental assurance program that included assembly/subsystem and system-level testing in the areas of dynamics, thermal, and electromagnetic (EMC), as well as venting/pressure, dust, radiation, and solid-particle (meteoroid, orbital debris) analyses. Due to the Martian diurnal cycles of extreme temperature swings, the susceptible hardware that were mounted outside of the thermal controlled zones also underwent thermal cycling qualification of their packaging designs and manufacturing processes. This paper summarizes the environmental assurance program for the MER project, with emphasis on the pre-launch thermal testing program for ensuring that the rover hardware would operate and survive the Mars surface temperature extremes. These test temperatures are compared with some of the Mars surface operational temperature measurements. Selected anomalies resulting from operating the rover hardware in the Mars extreme thermal environment are also presented.


2017 ◽  
Vol 63 (No. 1) ◽  
pp. 11-16 ◽  
Author(s):  
M. Ketta ◽  
E. Tumova

The objective of the present study was to compare the eggshell characteristics and cuticle deposition of Lohmann Brown, Hy-Line Silver Brown, and Isa Brown layers kept in two different housing systems. The three laying hen genotypes were housed in enriched cages (100 hens, 750 cm<sup>2</sup>/hen, 10 hens/cage) and in littered pens (100 hens, 9 hens/m<sup>2</sup>, 10 hens/pen). The experiment was carried out in weeks 40–56 of hens age. Non-significant interactions of genotype and housing system for eggshell quality parameters and cuticle deposition were detected in this study. Egg weight was significantly affected by genotype (P ≤ 0.001) and housing system (P ≤ 0.043). The heaviest eggs were laid by Lohmann Brown, while the lightest eggs were produced by Hy-Line Silver Brown. Eggshell strength was not affected by genotype and housing system, however, genotype had a significant effect on eggshell thickness (P ≤ 0.033). Isa Brown eggs had thicker eggshells compared to Lohmann Brown and Hy-Line Silver Brown. However, a non-significant effect of housing system on eggshell thickness was observed. Eggshell percentage was significantly affected by both genotype and housing system. Genotype of laying hens had a significant effect on cuticle deposition; significantly higher cuticle deposition was observed in Lohmann Brown eggs (P ≤ 0.001). It could be concluded that genotype had a significant effect on eggshell quality parameters and cuticle deposition. However, the housing system effect was less important in these characteristics.


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