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Objective To investigate the role of exogenous carbon monoxide (CO) in improving anxiety-like behaviors in elderly rats under perioperative stress by inhibiting excessive autophagy of astrocytes. Methods Thirty-six clean healthy male SD rats (aged 18~20 months) were randomly divided into 3 groups (n=12): sham-operation group (Group S), peritoneal surgery group (Group P), and peritoneal surgery+carbon monoxide-releasing molecule 3 (CORM-3) group (Group PC). The rats in Group PC were injected with exogenous CORM-3 (4 mg/kg) via caudal vein immediately, and in 24 and 48 h after surgery. Open field test and elevated plus maze test were performed to evaluate the anxiety-like behaviors on the 7th day after surgery. The neuronal amount in the amygdala, the expression of Bcl-2 interacting protein 1 (Beclin 1) and ubiquitin (Ub) in the astrocytes, microglia and neurons were assessed by immunofluorescence assay. The expression levels of microtubule associated protein 1 light chain 3 (LC3) was detected by Western blotting. The number of autophagosomes in the amygdala were observed with transmission electron microscopy. Results The results of open field test and elevated plus maze test showed that, as compared with Group S, the percentage of staying time in the central area was significantly decreased in Group P and Group PC (P < 0.05), so were the percentages of open arm stay duration and entry times (P < 0.05), indicating increased anxiety-like behaviors in the rats from these 2 groups. The histopathological and Western blotting results suggested declined number of NeuN positive cells in the amygdala, up-regulated expression of Beclin 1 and Ub in the astrocytes, and elevated ratio of LC3Ⅱ/Ⅰ were observed in Group P and PC (P < 0.05). Under transmission electron microscope, no autophagosomes were found in the astrocytes of Group S, while they were observed in Group P and PC. However, the above indexes of Group PC were all remarkably improved in comparison with those of Group P (P < 0.05). Conclusion Exogenous CO can improve the anxiety-like behaviors in aged rats under perioperative stress, and the mechanism may be associated with its inhibition on excessive autophagy of astrocytes in the amygdala.

Conventional air purifiers are low effective in inactivating airborne bacteria and may cause secondary contamination by releasing endotoxins. In this study, a novel air purifier was developed and used in a static chamber, which used slightly acidic electrolysed water (SAEW) solutions as the circulating disinfectant spray medium that automatically renewed every 30 min. During the 30-minute operation, the air and solution samples were collected to measure the bacteria and endotoxin concentration by using a culturable-based method and a limulus amoebocyte lysate assay kit, respectively. The pH and endotoxin of the circulating solution were gradually increased, and the available chlorine concentration (ACC, from 87 to 50 mg/L) was decreased. Although airborne bacteria were reduced significantly, the levels of airborne endotoxins at the inlet and outlet of the purifier remained constant. Moreover, a validation experiment revealed that SAEW, with ACC of 20, 60 and 100 mg/L, cannot inactivate standard endotoxin solutions. In the experimental chamber, the airborne bacteria level (1142 CFU/m3) was significantly lower compared to the control chamber (3325 CFU/m3), with no significant difference in airborne endotoxin levels between the chambers. Our results showed that the SAEW spray air purifier could effectively remove airborne bacteria without increasing airborne endotoxin levels within a 30-minute operational period. [ABSTRACT FROM AUTHOR]

Simple Summary: A suitable environment inside broiler houses is crucial to broiler health, welfare, and productivity. High stocking density can easily lead to uneven temperature conditions, which may cause broilers to experience cold or heat stress. Therefore, the objectives of this article were to assess the temperature uniformity inside a commercial broiler barn and to investigate influencing factors on the temperature difference. In this study, temperature, wind velocity, and differential pressure sensors were installed in a commercial stacked-deck cage broiler house for continuously monitoring the environment. Results indicate that the maximum temperature difference increased from 1.85 °C to 6.43 °C, while the daily fluctuation increased from 2.27 °C to 5.80 °C. The lateral temperature distribution is the main reason for the poor overall temperature uniformity and stability. In the lateral direction, the temperature distribution changes periodically, with the maximum temperature difference varying from 1.98 °C to −2.14 °C (− indicating high-temperature location variation) within one day. This variation was significantly influenced by solar radiation and wind speed, which can lead to poor performance and higher mortality rates in broilers. Therefore, it is crucial to consider the influences of solar radiation and wind on the indoor environment when designing and managing chicken houses. The temperature inside broiler houses is crucial to broiler health, welfare, and productivity. High stocking density in broiler houses can easily lead to nonuniform temperature conditions, which would cause broilers to suffer cold and heat stress. It is essential to assess the temperature distribution inside broiler houses and investigate the factors that affect temperature uniformity. Therefore, in this study, temperature, wind velocity, and differential pressure were monitored in the aisle, at the sidewall inlet, and outside the sidewalls of a commercial stacked-deck cage broiler house in Northeast China aiming to continuously monitor the temperature throughout the entire fattening period. Results show that the maximum temperature difference increased from 1.85 °C to 6.43 °C, while the daily fluctuation increased from 2.27 °C to 5.80 °C. The highest temperature was consistently recorded at the side of the exhaust fans (p < 0.001) in the longitudinal direction. In the lateral direction, the temperature difference varies periodically with solar radiation. The average temperature at the southern location (23.58 ± 1.97 °C), which faces the sun, was higher than that at the northern location (23.35 ± 1.38 °C), which is in the shade, during periods of solar radiation (p < 0.001) at the last testing period. However, without solar radiation, the northern location recorded a warmer temperature (23.19 ± 1.41 °C) compared to the southern location (22.30 ± 1.67 °C) (p < 0.001). The lateral temperature differences are strongly positively correlated with solar radiation and wind speed (p < 0.001). In conclusion, the inside temperature nonuniformity and fluctuation increased as the broiler age increased, which affected the production performance of broilers. Nonuniform solar radiation and wind speed can lead to differences in the inlet temperature and air volume between both sidewalls, thereby affecting the uniformity of the lateral temperature inside the house. [ABSTRACT FROM AUTHOR]

Simple Summary: Low-pressure systems frequently occur during the summer in coastal areas and can be detrimental to commercial poultry houses. The effects of air temperature and humidity vary across different periods. Throughout the generation of low-pressure systems, landfall, and disappearance, air temperature and humidity changes can interfere with the housing environment. However, farmers often overlook the impact of low-pressure systems on large-scale poultry houses, which may impair the production of laying hens. This study investigated the effects of the different low-pressure systems on the housing environment and egg production in large-scale poultry houses in China. The results indicated that a single low-pressure system reduced the laying performance, whereas a sustained low-pressure system mitigated the impact on egg production. This study aimed to determine the effect of low-pressure systems on the environment and the laying performance of large-scale poultry houses during the summer and to provide a basis for farmers to adjust their environmental control strategies under extreme weather conditions. Low-pressure systems (LPSs) are among the most critical weather systems, producing excessive precipitation that causes air temperatures to drop and rise considerably. Acute temperature changes directly affect poultry feed intake (FI) and laying performance. To explore the effects of LPSs on hens, the parameters of air temperature, relative humidity, egg production, and feed utilization efficiency were evaluated during different LPSs in three houses. Results indicated that about 2.8 ± 0.7 d, 2.4 ± 0.5 d, and 2.4 ± 0.5 d before the LPS landfall in houses 1, 2, and 3, respectively, the indoor air temperature started to decrease, with the average decreases being 1.7 °C ± 0.4 °C, 2.4 °C ± 0.6 °C, and 1.8 °C ± 0.4 °C, respectively. Significant differences were observed between different LPSs for reducing indoor air temperature (p < 0.05) in the three houses. In house 1, the egg production rates (EPRs) were decreased by 6.6% and 1.1% when LPSs 1 and 2 landed. The average egg weight (AEW) and FI during the LPS landfall were significantly higher than those before the LPS landfall (p < 0.01). Under successive LPSs landfall in the three houses, the EPRs initially reduced by 3.9%, 4.0%, and 0.5%, respectively, but the second LPS event increased the EPRs by 1.8%, 5.3%, and 1.0%, respectively. Furthermore, the LPS landfall increased the feed conversion ratio (FCRe) in the three houses, all above 2.00. In conclusion, LPSs can reduce heat stress, lower the EPRs, and lead to higher FI, FCRe, and AEW. [ABSTRACT FROM AUTHOR]

Simple Summary: In commercial hatcheries, chicken embryos are incubated in complete darkness. However, in a natural environment, chicken embryos receive light stimulation during the incubation process as hens need to leave the nest to feed or turn the eggs. Therefore, providing light during incubation is closer to the natural growth environment of chicken embryos, which may have a positive effect on their growth and development. This study investigated the effects of providing different wavelengths of light during incubation on the behaviour, growth, immunity, and stress responses of post-hatch chicks. The results indicated that providing white light during incubation may enhance the growth performance of post-hatch chicks and potentially improve their ability to cope with environmental changes. This study aims to determine the effects of light exposure during incubation on the growth and development of post-hatch chicks and to provide a basis for the development of effective lighting strategies during the incubation period. Manipulation of light during incubation may have an effect on post-hatch chicks through the role of prenatal stage. The effects of providing different wavelengths of light (white, blue, and green lights, dark as control) during incubation on the growth performance, organ development, immune response, stress related hormones, digestive enzymes and behaviour of post-hatch chicks were investigated for 1–42 days. A total of 60 chicks per light treatment in three batches were used in this study. The results showed that the percentage of chicks accessing to feed and water resources appeared not to be affected by incubation light. Chicks hatched under white light were found to have a growth advantage (p < 0.05). The weight of organs (except thymus), IgA, IgY, IgM and heterophil to lymphocyte (H/L) ratio for post-hatch chicks were not affected by incubation light (p > 0.05). Thymus weight was reduced in chicks incubated under blue light compared to dark incubation (p < 0.05). The jejunum amylase and ileum lipase activities were significantly affected by the light treatments (p < 0.01). All light incubation chicks had stable plasma corticosterone levels and may have better ability to cope with environmental changes. Hence, white light photoperiod incubation may have potential to improve post-hatch chicks' growth performance and environmental adaptability. [ABSTRACT FROM AUTHOR]