Special Issue "Housing Environment and Farm Animals' Well-Being"

A special issue of Animals (ISSN 2076-2615). This special issue belongs to the section "Animal Welfare".

Deadline for manuscript submissions: 31 December 2021.

Special Issue Editors

Dr. Lilong Chai
E-Mail Website
Guest Editor
College of Agricultural and Environmental Sciences Athens Campus, Athens, GA, USA
Interests: animal environmental engineering; precision poultry farming; poultry health and welfare
Special Issues and Collections in MDPI journals
Dr. Yang Zhao
E-Mail Website
Guest Editor
Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
Interests: animal smart sensoring; robotics; behavior monitoring; welfare assessment; airborne transmission of pathogens; and environment management
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

Housing enviornment affects the health and well-being of farm animals of livestock and poultry raised in concentrated animal feeding operations (CAFOs). Poor air quality (e.g., high levels of indoor ammonia, particulate matter, and airborne bacteria) may deteriorate animals’ health/well-being over time in CAFOs. Mitigating air pollutants generation and suppressing levels of housing air pollutants are critical for maintaining the well-being of farm animals. This special issue of Animals “Housing Environment and Farm Animals' Well-Being” encourages the submission of original research, review, and communication related to livestock and poultry environmental management, air quality control, emissions mitigation, and assessment of animal health and well-being. Publications in this issue will provide references for researchers, students, and animal agriculture producers to enhance on-farm environmental management and animal well-being.

Dr. Lilong Chai
Dr. Yang Zhao
Guest Editors

Manuscript Submission Information

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Keywords

  • farm animals’ environment
  • animal health
  • livestock well-being
  • air quality
  • emissions mitigation

Published Papers (7 papers)

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Research

Article
Evaluation of Thermal Indices as the Indicators of Heat Stress in Dairy Cows in a Temperate Climate
Animals 2021, 11(8), 2459; https://doi.org/10.3390/ani11082459 - 21 Aug 2021
Viewed by 378
Abstract
Many thermal indices (TIs) have been developed to quantify the severity of heat stress in dairy cows. Systematic evaluation of the representative TIs is still lacking, which may cause potential misapplication. The objectives of this study were to evaluate the theoretical and actual [...] Read more.
Many thermal indices (TIs) have been developed to quantify the severity of heat stress in dairy cows. Systematic evaluation of the representative TIs is still lacking, which may cause potential misapplication. The objectives of this study were to evaluate the theoretical and actual performance of the TIs in a temperate climate. The data were collected in freestall barns at a commercial dairy farm. The heat transfer characteristics of the TIs were examined by equivalent air temperature change (ΔTeq). One-way ANOVA and correlation were used to test the relationships between the TIs and the animal-based indicators (i.e., rectal temperature (RT), respiration rate (RR), skin temperature (ST), and eye temperature (ET)). Results showed that the warming effect of the increased relative humidity and the chilling effect of the increased wind speed was the most reflected by the equivalent temperature index (ETI) and the comprehensive climate index (CCI), respectively. Only the equivalent temperature index for cows (ETIC) reflected that warming effect of solar radiation could obviously increase with increasing Ta. The THI and ETIC showed expected relationships with the RT and RR, whereas the CCI and ETIC showed expected relationships with the ST and ET. Moreover, CCI showed a higher correlation with RT (r = 0.672, p < 0.01), ST(r = 0.845, p < 0.01), and ET (r = 0.617, p < 0.01) than other TIs (p < 0.0001). ETIC showed the highest correlation with RR (r = 0.850, p < 0.01). These findings demonstrated that the CCI could be the most promising thermal index to assess heat stress for housed dairy cows. Future research is still needed to develop new TIs tp precisely assess the microclimates in cow buildings. Full article
(This article belongs to the Special Issue Housing Environment and Farm Animals' Well-Being)
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Article
Effects of Cold Exposure on Performance and Skeletal Muscle Fiber in Weaned Piglets
Animals 2021, 11(7), 2148; https://doi.org/10.3390/ani11072148 - 20 Jul 2021
Viewed by 840
Abstract
Low-temperature is one of the most significant risks for the animal industry. In light of this, the present study aimed to explore the effects of low-temperature on growth performance, nutrient digestibility, myofiber types and mitochondrial function in weaned piglets. A total of sixteen [...] Read more.
Low-temperature is one of the most significant risks for the animal industry. In light of this, the present study aimed to explore the effects of low-temperature on growth performance, nutrient digestibility, myofiber types and mitochondrial function in weaned piglets. A total of sixteen 21-day-old male Duroc × Landrace × Yorkshire (DLY) piglets were randomly divided into a control group (CON, 26 ± 1 °C) and a low-temperature group (LT, 15 ± 1 °C), with eight duplicate piglets in each group. The trial period lasted for 21 days. We showed that LT not only increased the ADFI (p < 0.05), as well as increasing the diarrhea incidence and diarrhea index of weaned piglets in the early stage of the experiment (p < 0.01), but it also decreased the apparent digestibility of crude protein (CP), organic matter (OM) and dry matter (DM) (p < 0.05). Meanwhile, in the LT group, the mRNA expression of MyHC IIa (p < 0.05) in longissimus dorsi muscle (LM) and MyHC I (p < 0.01) in psoas muscle (PM) were increased, while the mRNA expression of MyHC IIx in PM was decreased (p < 0.05). In addition, LT increased the mRNA expression of mitochondrial function-related genes citrate synthase (CS) and succinate dehydrogenase-b (SDHB) in LM, as well as increased the mRNA expression of CS (p < 0.05) and carnitine palmitoyl transferase-1b (CPT-1b) (p < 0.01) in PM. Furthermore, LT increased the T-AOC activity in serum and LM (p < 0.01), as well as increased the T-SOD activity in PM (p < 0.05). Taken together, these findings showed that low-temperature could negatively affect the growth performance and nutrient digestibility, but resulted in a shift toward oxidative muscle fibers, which may occur through mitochondrial function regulation. Full article
(This article belongs to the Special Issue Housing Environment and Farm Animals' Well-Being)
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Article
A Comparison of the Behavior, Physiology, and Offspring Resilience of Gestating Sows When Raised in a Group Housing System and Individual Stalls
Animals 2021, 11(7), 2076; https://doi.org/10.3390/ani11072076 - 12 Jul 2021
Viewed by 900
Abstract
Being in a confined environment causes chronic stress in gestating sows, which is detrimental for sow health, welfare and, consequently, offspring physiology. This study assessed the health and welfare of gestating sows housed in a group housing system compared to individual gestation stalls. [...] Read more.
Being in a confined environment causes chronic stress in gestating sows, which is detrimental for sow health, welfare and, consequently, offspring physiology. This study assessed the health and welfare of gestating sows housed in a group housing system compared to individual gestation stalls. After pregnancy was confirmed, experimental sows were divided randomly into two groups: the group housing system (GS), with the electronic sow feeding (ESF) system; or individual stall (IS). The behavior of sows housed in the GS or IS was then compared; throughout pregnancy, GS sows displayed more exploratory behavior, less vacuum chewing, and less sitting behavior (p < 0.05). IS sows showed higher stress hormone levels than GS sows. In particular, at 41 days of gestation, the concentration of the adrenocorticotropic hormone (ACTH) and adrenaline (A) in IS sows was significantly higher than that of GS sows, and the A level of IS sows remained significantly higher at 71 days of gestation (p < 0.01). The lipopolysaccharide (LPS) test was carried out in the weaned piglets of the studied sows. Compared with the offspring of gestating sows housed in GS (PG) or IS (PS), PG experienced a shorter period of high temperature and showed a quicker return to the normal state (p < 0.05). Additionally, their lower levels of stress hormone (p < 0.01) suggest that PG did not suffer from as much stress as PS. These findings suggested that gestating sows housed in GS were more able to carry out their natural behaviors and, therefore, had lower levels of stress and improved welfare. In addition, PG also showed better disease resistance and resilience. These results will provide a research basis for the welfare and breeding of gestating sows. Full article
(This article belongs to the Special Issue Housing Environment and Farm Animals' Well-Being)
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Article
Modeling of Heat Stress in Sows Part 2: Comparison of Various Thermal Comfort Indices
Animals 2021, 11(6), 1498; https://doi.org/10.3390/ani11061498 - 21 May 2021
Viewed by 663
Abstract
Heat stress has an adverse effect on the production performance of sows, and causes a large economic loss every year. The thermal environment index is an important indicator for evaluating the level of heat stress in animals. Many thermal indices have been used [...] Read more.
Heat stress has an adverse effect on the production performance of sows, and causes a large economic loss every year. The thermal environment index is an important indicator for evaluating the level of heat stress in animals. Many thermal indices have been used to analyze the environment of the pig house, including temperature and humidity index (THI), effective temperature (ET), equivalent temperature index of sows (ETIS), and enthalpy (H), among others. Different heat indices have different characteristics, and it is necessary to analyze and compare the characteristics of heat indices to select a relatively suitable heat index for specific application. This article reviews the thermal environment indices used in the process of sow breeding, and compares various heat indices in four ways: (1) Holding the value of the thermal index constant and analyzing the equivalent temperature changes caused by the relative humidity. (2) Analyzing the variations of ET and ETIS caused by changes in air velocity. (3) Conducting a comparative analysis of a variety of isothermal lines fitted to the psychrometric chart. (4) Analyzing the distributions of various heat index values inside the sow barn and the correlation between various heat indices and sow heat dissipation with the use of computational fluid dynamics (CFD) technology. The results show that the ETIS performs better than other thermal indices in the analysis of sows’ thermal environment, followed by THI2, THI4, and THI7. Different pigs have different heat transfer characteristics and different adaptability to the environment. Therefore, based on the above results, the following suggestions have been given: The thermal index thresholds need to be divided based on the adaptability of pigs to the environment at different growth stages and the different climates in different regions. An appropriate threshold for a thermal index can provide a theoretical basis for the environmental control of the pig house. Full article
(This article belongs to the Special Issue Housing Environment and Farm Animals' Well-Being)
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Article
Modeling of Heat Stress in Sows—Part 1: Establishment of the Prediction Model for the Equivalent Temperature Index of the Sows
Animals 2021, 11(5), 1472; https://doi.org/10.3390/ani11051472 - 20 May 2021
Cited by 1 | Viewed by 733
Abstract
Heat stress affects the estrus time and conception rate of sows. Compared with other life stages of pigs, sows are more susceptible to heat stress because of their increased heat production. Various indicators can be found in the literature assessing the level of [...] Read more.
Heat stress affects the estrus time and conception rate of sows. Compared with other life stages of pigs, sows are more susceptible to heat stress because of their increased heat production. Various indicators can be found in the literature assessing the level of heat stress in pigs. However, none of them is specific to assess the sows’ thermal condition. Moreover, thermal indices are mainly developed by considering partial environment parameters, and there is no interaction between the index and the animal’s physiological response. Therefore, this study aims to develop a thermal index specified for sows, called equivalent temperature index for sows (ETIS), which includes parameters of air temperature, relative humidity and air velocity. Based on the heat transfer characteristics of sows, multiple regression analysis is used to combine air temperature, relative humidity and air velocity. Environmental data are used as independent variables, and physiological parameters are used as dependent variables. In 1029 sets of data, 70% of the data is used as the training set, and 30% of the data is used as the test set to create and develop a new thermal index. According to the correlation equation between ETIS and temperature-humidity index (THI), combined with the threshold of THI, ETIS was divided into thresholds. The results show that the ETIS heat stress threshold is classified as follows: suitable temperature ETIS < 33.1 °C, mild temperature 33.1 °C ≤ ETIS < 34.5 °C, moderate stress temperature 34.5 °C ≤ ETIS < 35.9 °C, and severe temperature ETIS ≥ 35.9 °C. The ETIS model can predict the sows’ physiological response in a good manner. The correlation coefficients R of skin temperature was 0.82. Compared to early developed thermal indices, ETIS has the best predictive effect on skin temperature. This index could be a useful tool for assessing the thermal environment to ensure thermal comfort for sows. Full article
(This article belongs to the Special Issue Housing Environment and Farm Animals' Well-Being)
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Article
Evaluation of TiO2 Based Photocatalytic Treatment of Odor and Gaseous Emissions from Swine Manure with UV-A and UV-C
Animals 2021, 11(5), 1289; https://doi.org/10.3390/ani11051289 - 30 Apr 2021
Viewed by 524
Abstract
It is essential to mitigate gaseous emissions that result from poultry and livestock production to increase industry sustainability. Odorous volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gases (GHGs) have detrimental effects on the quality of [...] Read more.
It is essential to mitigate gaseous emissions that result from poultry and livestock production to increase industry sustainability. Odorous volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gases (GHGs) have detrimental effects on the quality of life in rural communities, the environment, and climate. This study’s objective was to evaluate the photocatalytic UV treatment of gaseous emissions of odor, odorous VOCs, NH3, and other gases (GHGs, O3—sometimes considered as by-products of UV treatment) from stored swine manure on a pilot-scale. The manure emissions were treated in fast-moving air using a mobile lab equipped with UV-A and UV-C lights and TiO2-based photocatalyst. Treated gas airflow (0.25–0.76 m3∙s−1) simulates output from a small ventilation fan in a barn. Through controlling the light intensity and airflow, UV dose was tested for techno-economic analyses. The treatment effectiveness depended on the UV dose and wavelength. Under UV-A (367 nm) photocatalysis, the percent reduction of targeted gases was up to (i) 63% of odor, (ii) 51%, 51%, 53%, 67%, and 32% of acetic acid, propanoic acid, butanoic acid, p-cresol, and indole, respectively, (iii) 14% of nitrous oxide (N2O), (iv) 100% of O3, and 26% generation of CO2. Under UV-C (185 + 254 nm) photocatalysis, the percent reductions of target gases were up to (i) 54% and 47% for p-cresol and indole, respectively, (ii) 25% of N2O, (iii) 71% of CH4, and 46% and 139% generation of CO2 and O3, respectively. The results proved that the UV technology was sufficiently effective in treating odorous gases, and the mobile lab was ready for farm-scale trials. The UV technology can be considered for the scaled-up treatment of emissions and air quality improvement inside livestock barns. Results from this study are needed to inform the experimental design for future on-farm research with UV-A and UV-C. Full article
(This article belongs to the Special Issue Housing Environment and Farm Animals' Well-Being)
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Article
Effects of a Partially Perforated Flooring System on Ammonia Emissions in Broiler Housing—Conflict of Objectives between Animal Welfare and Environment?
Animals 2021, 11(3), 707; https://doi.org/10.3390/ani11030707 - 05 Mar 2021
Cited by 1 | Viewed by 619
Abstract
A partially (50%) perforated flooring system showed positive effects on health- and behavior-based welfare indicators without affecting production performance. Ammonia (NH3) is the most common air pollutant in poultry production, with effects on animal welfare and the environment. The objectives of [...] Read more.
A partially (50%) perforated flooring system showed positive effects on health- and behavior-based welfare indicators without affecting production performance. Ammonia (NH3) is the most common air pollutant in poultry production, with effects on animal welfare and the environment. The objectives of animal welfare and environmental protection are often incompatible. Therefore, this study addresses the question of how a partially perforated flooring system affects NH3 emissions. According to German regulations, three fattening periods were carried out with 500 Ross 308 broilers per barn (final stocking density: 39 kg m−2). The experimental barn was equipped with an elevated perforated area in the supply section, accessible by perforated ramps. The remaining area in the experimental barn and the control barn were equipped with wood shavings (600 g m−2). Besides the different floor types, management was identical. Air temperature (Temp), relative air humidity (RH), NH3 concentration, and ventilation rate (VR) were measured continuously. Furthermore, dry matter (DM) content, pH, and litter quality were assessed. Towards the end of the fattening periods, the NH3 emission rate (ER) of the partially perforated flooring system was higher compared with that of the littered control barn (all p < 0.001). This effect is mainly caused by the higher NH3 concentrations, which are promoted by the lack of compaction underneath the elevated perforated area and the increase in pH value under aerobic conditions. Nevertheless, the partially perforated flooring system offers different approaches for NH3 reduction that were previously not feasible, potentially contributing equally to animal welfare and environmental protection. Full article
(This article belongs to the Special Issue Housing Environment and Farm Animals' Well-Being)
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Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Effects of a partially perforated flooring system on ammonia emissions in broiler housing – Conflict of objectives between animal welfare and environment?
Authors: Carolin Adler; Alexander J. Schmithausen; Manfred Trimborn; Sophia Heitmann; Birgit Spindler; Inga Tiemann; Nicole Kemper; Wolfgang Büscher
Affiliation: University of Bonn, Bonn, Germany
Abstract: The partially (50%) perforated flooring system showed positive effects on health- and behavior-based welfare indicators without affecting production performance. Ammonia (NH3) is the most common air pollutant in poultry production with an effect on animal welfare and environment. The objectives of animal welfare and environment are often incompatible. Therefore, this study addresses the question how the partially perforated flooring system affects NH3 emissions. Three fattening periods were carried out with 500 Ross 308 broilers per barn (final stocking density: 39 kg m-2). The experimental barn was equipped with an elevated perforated area in the supply section, accessible by perforated ramps. The remaining area in the experimental barn and the control barn were equipped with wood shavings (600 g m-2). Beside the different floor types, management was identical. Air temperature (Temp), relative air humidity (RH), NH3 concentration, and ventilation rate (VR) were measured continuously. Furthermore, dry matter content (DM), pH, and litter quality were assessed. Towards the end of the fattening periods, the NH3 emission rate (ER) of the partially perforated flooring system was higher compared to the littered control barn (all P < 0.001). This effect is mainly caused by the higher NH3 concentrations, which are promoted by the lack of compaction underneath the elevated perforated area and the increase in pH value under aerobic conditions. Nevertheless, the system offers different approaches for NH3 reduction that were previously not feasible and potentially contributing equally to animal welfare and environmental protection.

Title: Evaluation of TiO2 based photocatalytic treatment of odor and gaseous emissions from swine manure with UV-A and UV-C.
Authors: Jacek Koziel
Affiliation: Iowa State University, Ames, United States
Abstract: It is essential to mitigate gaseous emissions that result from poultry and livestock production to increase industry sustainability. Odorous volatile organic compounds (VOCs), ammonia (NH3), hydrogen sulfide (H2S), and greenhouse gases (GHGs) have detrimental effects on the quality of life in rural communities, the environment, and climate. This study's objective was to evaluate the photocatalytic UV treatment of gaseous emissions of odor, odorous VOCs, NH3, and other gases (GHGs, O3 – sometimes considered as by-products of UV treatment) from stored swine manure on a pilot-scale. The manure emissions were treated in fast-moving air using a mobile lab equipped with UV-A and UV-C lights and TiO2-based photocatalyst. Treated gas airflow (0.25 to 0.76 m3∙s-1) simulates output from a small ventilation fan in a barn. Through controlling the light intensity and airflow, UV dose was tested for techno-economic analyses. The treatment effectiveness depended on the UV dose and wavelength. Under UV-A (367 nm) photocatalysis, the percent reduction of targeted gases was up to i) 63% of odor, ii) 51%, 51%, 53%, 67%, and 32% of acetic acid, propanoic acid, butanoic acid, p-cresol, and indole, respectively, iii) 14% of nitrous oxide (N2O), iv) 100% of O3, and 26% generation of CO2. Under UV-C (185+254 nm) photocatalysis, the percent reductions of target gases were up to i) 54% and 47% for p-cresol and indole, respectively, ii) 25% of N2O, iii) 71% of CH4, and 46% & 139% generation of CO2 & O3, respectively. The results proved that the UV technology was sufficiently effective in treating odorous gases, and the mobile lab was ready for farm-scale trials. The UV technology can be considered for the scaled-up treatment of emissions and air quality improvement inside livestock barns.

Title: Responses of Heavy Broilers’ Surface Temperature to Heat Stress under Air Velocity Treatment
Authors: Suraiya Akter1, Yingying Liu1,2, Yan Qian1,2, Bin Cheng1, Derek West1, John Classen1, Lingjuan Wang-Li1*, Hernan Cordova3, Viviana San Martin Diaz3, Edgar Oviedo3
Affiliation: 1Department of Biological and Agricultural Engineering, North Carolina State University 2Nanjing Agricultural University, China 3Prestage Poultry Science Department, North Carolina State University *Corresponding author

Title: Modeling of Heat Stress in Sows. Part 1: Establishment of the Prediction Model for the Equivalent Temperature Index of the Sows
Authors: Mengbing Cao; Chao Zong; Xiaoshuai Wang; Guanghui Teng; Yanrong Zhuang; Kaidong Lei
Affiliation: College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
Abstract: Heat stress affects the estrus time and conception rate of sows. Compared with other stages of pigs, sows are more susceptible to heat stress because of more heat production. Various indicators can be found in literature assessing the level of heat stress in pigs. However, none of them is specific to assess the sows’ thermal condition. Moreover, those thermal indices were mainly developed by considering partial environment parameters, and there is no interaction between the index and the animal’s physiological response. Therefore, this study aims to develop a thermal index specified for sows, called equivalent temperature index for sows (ETIS), which includes parameters of air temperature, relative humidity, air velocity. Environmental and physiological data were aggregated to develop and validate the new thermal index. The ETIS heat stress threshold was proposed by associating with the temperature-humidity index (THI) threshold. Results show that the ETIS model can predict sows’ physiological response in a good manner. The correlation coefficients R of skin temperature was 0.82, respectively. Compared to early developed thermal indices, ETIS has the best predictive effect on skin temperature. This index could be a useful tool for assessing the thermal environment to ensure thermal comfort for sows.

Title: Modeling of Heat Stress in Sows. Part 2: Comparison of Various Thermal Comfort Indices
Authors: Mengbing Cao; Chao Zong; Yanrong Zhuang; Guanghui Teng; Shengnan Zhou; Ting Yang
Affiliation: College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
Abstract: Heat stress has an adverse effect on the production performance of pigs, and the economic loss caused by heat stress every year is immeasurable. The thermal environment index is an important indicator for evaluating the level of heat stress in animals. Many thermal indices have been used to analyze the environment of the pig house, including temperature and humidity index (THI), effective temperature (ET), Equivalent Temperature Index for Sows (ETIS) and enthalpy (H), etc. Different heat indices have different characteristics, and it is necessary to analyze and compare the characteristics of heat indices to select a relatively suitable heat index for specific application. This article combs the thermal environment index used in the process of pig breeding, and compares various heat indices in four ways: 1) Equivalent temperature change method, comparing the change of equivalent temperature caused by different relative humidity; 2) Comparison of the influence of air flow velocity on the thermal index, comparing the influence of different air velocity on ET and ETIS; 3) Humidity Enthalpy diagram method, the iso-exponential line fitting of different heat indices is compared and analyzed in the humidity enthalpy diagram; 4) Numerical simulation method, using computational fluid dynamics (CFD) technology to analyze the thermal environment distribution of simple pig houses under different heat indices, and Analyze its correlation with the heat dissipation of pigs. The results show that the ETIS performs better than other thermal indices in the analysis of sow’s thermal environment, followed by THI2, THI4 and THI7. There are differences in the heat transfer characteristics of pigs at different stages, and animals have different adaptability to different environments. Therefore, based on the above results, the author puts forward the following suggestions: And according to the pig production performance of different regions and different growth stages, the thermal index threshold is divided. Establish a complete thermal index distribution and thermal threshold zone based on different regions to provide a more accurate control basis for environmental control.

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