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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]

Poultry suffer from large temperature variations with traditional tunnel ventilation and wet-pad evaporative cooling (TV) system in continental climates, which negatively influences production performance, resulting in significant economic losses. An ideal ventilation system is desired for retrofitted and new poultry houses. A new ventilation (NV) system was designed to mitigate the air temperature variations and improve the uniformity in poultry houses located in continental climate regions. The evaporative cooling pads were installed on both sidewalls and exhaust fans were located on a gable wall in the NV system. The system could be operated in different modes for daytime and night time by automatically running or not running evaporative cooling according to indoor set-point temperature. The performance of the NV system was evaluated in comparison with a TV system by measuring the thermal environment and layer performance of two commercial poultry houses with different ventilation systems. The results showed that the NV system provided a cooler air environment than the TV system, and the maximum fluctuation in average air temperature was reduced to 1 °C vs. 6.1 °C in TV system. Based on temperature-humidity heat stress index (THI) values, compared to the TV system, the NV system reduced heat stress time across the building in horizontal and vertical planes. The egg production was higher in the NV system house than in the TV system house (20.3% vs 18.9%), and the mean bird's mass in NV system house was 21 g higher than in TV system house. • Evaporative cooling pads of new ventilation system were installed in commercial house. • The new ventilation system provided a cooler air environment than the traditional system. • The new ventilation (NV) system reduced temperature-humidity heat stress index values. • Egg production was higher in the NV house than in the traditional system (TV) house. • The mean bird mass was 21 g higher in the NV house than in the TV house. [ABSTRACT FROM AUTHOR]

Simple Summary: So far, traditional cages are still the dominant housing systems for laying hens all over the world. However, during the later phase of the laying cycle, laying hens in conventional cages are highly susceptible to osteoporosis due to a calcium deficiency, which is accompanied by a decrease in production performance and egg quality, and an increase in mortality. B-wave ultraviolet (UVB) radiation (290–315 nm) can penetrate the skin and converts 7-dehydrocholesterol (7-DHC) to previtamin D3, which is rapidly converted to vitamin D3, which promotes the body's absorption of calcium and phosphorus, as well as bone metabolism. Hence, we hypothesize that UVB exposure using light-emitting diode (LED) lights on laying hens during the later phase of the laying cycle can promote health and welfare of layers. This study aims to improve bone quality and egg quality by utilizing light environment regulation, in order to provide a theoretical basis for the application of UVB-LED lights for laying hens during the later phase of the laying cycle. Caged laying hens are prone to calcium deficiencies, resulting in osteoporosis and egg quality deterioration during the later phase of the laying cycle. Fluorescent light and light-emitting diodes (LEDs), which are widely used in poultry houses now, are both deficient in ultraviolet (UV) light, the lack of which is detrimental to chickens' welfare and health. This study was conducted to investigate the effects of UVB light supplementation using LEDs on the bone traits, blood parameters, laying performance, and egg quality for caged laying hens at 68–75 weeks. In total, 120 Jingfen laying hens were randomly assigned to four different groups, with three replicates in each group (10 hens in each cage as a replicate). UVB-LED lamps installed under the feed troughs were used to provide UVB light (296–316 nm) for the birds in the three treatment groups (1 h, 2 h, and 3 h UVB supplementation per day, respectively), while the control group was not exposed to UVB-LED light. Bone traits, egg quality, and amounts of calcium (Ca), phosphorus (P), 25-hydroxyvitamin D3 (25(OH)D3), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and 7-dehydrocholesterol (7-DHC) in both the serum and egg yolks were tested during the experiment. The results demonstrated that UVB-LED exposure significantly increased the bone mineral density (BMD), egg production, and yolk 1,25(OH)2D3 concentrations (p < 0.05), and reduced the content of serum 7-DHC (p < 0.05), especially in the 2 h/day group; however, it did not improve egg quality, vitamin D metabolites, or photoproducts in the serum and yolk 25(OH)2D3 concentrations (p > 0.05). This study concluded that UVB supplementation using LEDs had a positive effect on caged laying hens during the later phase of the laying cycle. [ABSTRACT FROM AUTHOR]

Egg production and consumption of eggs in China account for about 40% of the global total, and this constitutes a significant demand for water resources. The shortage of water resources in China means egg production in this country has serious water challenges. However, there are few studies concerning water use in egg production. In this study, the water footprint network (WFN) methodology was applied to analyze the water footprint (WF) of intensive egg production using a typical parent-stock layer breeder farm in North China as a model, which raises 208,663 layer breeders and produces about 2791.39 t eggs per year. The feed and water consumption over 353 days were collected for analysis, and the water footprint of chicken eggs was estimated at the farm level. The water footprint of eggs in a parent-stock layer breeder farm in China was therefore assessed in detail for the first time, and suggestions are put forward to reduce the egg water footprint from the perspective of the production chain and improving water use efficiency on the farm. The results show that (1) the green WF of eggs (water volume/egg weight) ranged from 1.917 to 2.114 m3/kg, the blue WF was 0.584 to 0.644 m3/kg and the grey WF was 0.488 to 0.538 m3/kg; (2) the indirect WF generated by feed contributed over 99.8% of the total; (3) eggs laid by Hy-line Brown hens have a lower WF than those from Hy-line Sonia hens, and the studied layer breeder farm had a higher WF than the global average based on the literature. In this paper, the variation of the WF was also analyzed, and some advice on water management for layer farms in China is provided. [ABSTRACT FROM AUTHOR]