Search

Free-range broiler production is an effective combination of ecological and economic benefits which should be further standardized. The purpose of this study was to evaluate the effects of free-range broiler production on ecosystem by measuring the changes in vegetation characteristics and soil physicochemical properties under different stocking densities. A natural meadow with rich biodiversity was created and further divided into three groups. The broilers were reared in door and provided range access around 6 to 22 weeks of age with two different densities, 600 and 1200 broilers/ha. The vegetation characteristics and soil physicochemical properties, such as total coverage, soil nutrition and pH value, were measured at the beginning and the end of stocking. The results showed that the vegetation characteristics and soil physicochemical properties changed significantly after free-range stocking. The dominant plants, total coverage, richness index, diversity and biomass above-ground of treatment groups illustrated a considerable difference comparing with those in control group, and the indicators of soil physicochemical properties in treatment groups increased remarkably except the pH value. The present study demonstrated the higher stocking density would cause a more serious destruction of vegetation characteristics and modification of soil physicochemical properties, which suggested that an even lower stocking density or an alternative management such as rotational grazing could be a better choice for free-range broiler production. [ABSTRACT FROM AUTHOR]

For a long time, the management and analysis of broiler breeding information in China remain in the 1.0 era of manual recording, careless processing, non-standard analysis and non-standard filing, and lack of accurate and intelligent information management and analysis system, which limit the development of broiler breeding industry. Based on the actual needs of broiler breeding in China, the project team focused on the collection, management and analysis of broiler breeding information and successfully developed intelligent Management and Analysis System for Broiler Breeding Information. The system is the most complete management and analysis system of broiler breeding information in China, which is closely combined with practice. It has been successfully applied to broiler breeding by more than 10 breeding institutions in China, some of which are national-level core broiler breeding farms. The successful development and application of the system will effectively improve the efficiency of broiler breeding in China, narrow the gap between China and developed countries, open the 2.0 era of precise, intelligent and modular broiler breeding, and improve the core competitiveness of broiler breeding in China. [ABSTRACT FROM AUTHOR]

Highlights • Turbulence flow contributes to the excessive convective heat losses for the birds. • Uniform indoor air movement reduce the temperature at the end of the poultry house. • Side-wall air inlets placed at the middle of the house reduce the temperature at the end of the house. • Side-wall windows have strong effects on the indoor environmental parameters. Abstract Ventilation system is crucial for poultry houses to control the indoor climate and air quality. The tunnel ventilation system is widely applied for large-scale poultry buildings in China but only limited scientific researches regarding the flow pattern, temperature distribution and design criteria are available in the literature. Thanks to the fast development of computer technology, Computational Fluid Dynamics (CFD) techniques were used in present study to investigate the indoor air movement, air temperature and relatively humidity. A three-dimensional CFD model was built according to the real dimensions of a laying hen house and the model was validated by comparing the simulation results with the field measurements at 30 positions. Meanwhile, statistical analysis was performed to determine the differences between different boundary conditions regarding the agreement between measured and CFD simulated results. Optimization of air inlet configurations was performed by using the validated CFD model and it was found that the uniformity of indoor air movement could prevent excessive local convective heat losses and reduce the temperature at the end of the house. Furthermore, the air inlets placed at the middle of the side wall could significantly reduce the high temperature expected at the end of the building without using extra energy, which is especially important for large-scale poultry farms with long buildings. The performance of side-wall windows was also examined and preliminary guidance was provided to effectively regulate the indoor climate by using these windows with the help of environmental monitoring systems. The present study contributes to the understanding and design of the tunnel ventilation system used in poultry houses. [ABSTRACT FROM AUTHOR]

Although several cross-sectional studies have shown an association of metabolic syndrome (MetS) with nodular thyroid disease, related prospective studies are scarce. This study investigated the association of MetS with thyroid nodule (TN) incidence in Chinese adults, and explored whether the development of or recovery from MetS is associated with changes in the risk of developing TNs. A total of 4,749 Chinese aged 18-65 years were involved in this 6-year prospective study. The association of MetS with TN prevalence was examined. TN-free individuals at baseline ( n = 3,133) were further examined. TN incidence rates in groups with different MetS statuses (MetS-free, MetS-developed, MetS-recovery and MetS-chronic) were analyzed. Of all participants, 18.21 and 31.65% had MetS and TNs, respectively. MetS patients had a higher TN prevalence than the non-MetS group (31.08 vs. 19.81% in males, p < 0.01; 59.52 vs. 39.59% in females, p < 0.01). Sex, age and MetS were independent risk factors for TNs. At a median follow up of 5.94 years, the MetS-chronic group (4.37/100 person-years) had a higher risk of TNs (adjusted incidence rate ratio [IRR] = 1.288 [95% CI 1.014-1.636]) compared with the MetS-free group (2.72/100 person-years) in the whole cohort. In males, the MetS-chronic group (3.76/100 person-years) had a higher risk of TNs (adjusted IRR = 1.367 [95% CI 1.017-1.835]) compared with the MetS-free group (2.31/100 person-years). In females, the risk of TNs was significantly higher in the MetS-chronic (6.44/100 person-years) and MetS-developed (6.31/100 person-years) groups compared with the MetS-free group (3.23/100 person-years)., (Copyright © 2020 Liang, Yu, Chen, Yang, Li, Hu, Huang, Kuang and Li.)