Characterization and comparison of the bacterial community between complete intensive and extensive feeding patterns in pigs

Analysis of Influencing Factors and Mechanism of Farmers' Green Production Behaviors in China

The green production behavior of pig farmers is the basis for high-quality development in animal husbandry. In order to solve the problem of poor green production behaviors in small- and medium-sized pig farmers, it is necessary to analyze the influencing factors and how they interact with each other. The Rational Peasant Theory and Prospect Theory were used in this paper to analyze the occurrence motivation of the green production behaviors of small- and medium-sized pig farmers. The Logit model and the ISM analysis method were used to test the influencing factors and their mechanisms. This was conducted using data from a study of 747 small- and medium-sized pig farmers in Henan Province. The results show that the green production behaviors of small- and medium-sized pig farmers are motivated by internal expected return, affected by the monitoring pressure from external stakeholders and limited by their own resource capacity; the influencing factors of different green production behaviors are different, and there are more influencing factors of scientific disease control, standardized management and waste recycling than of rational feeding. The following shows how the influencing factors on pig farmers' green production behavior interact with one another: level of education → external pressure, farming conditions and operating characteristics → cognition of return → green production behavior (i.e., cognition of return is the direct factor; external pressure, farming conditions and operating characteristics are indirect factors; and level of education is the underlying factor). Some measures should be implemented to promote green production behaviors, such as the continuation of the support for green production, the strengthening of supervision and publicity, the increasing of investment in technology and equipment, and the improving of the green production literacy of farmers. In conclusion, this paper deepens the understanding of the mechanism of green production behaviors of small- and medium-sized pig farmers, and provides the theoretical basis and concrete measures for the government and for pig farmers.

Research progress on distribution and exposure risk of microbial aerosols in animal houses

Environmental aerosols in animal houses are closely related to the productive performance and health level of animals living in the houses. Preferable housing environments can improve animal welfare and production efficiency, so it is necessary to monitor and study these environments. In recent years, there have been many large-scale outbreaks of respiratory diseases related to biological aerosols, especially the novel coronavirus that has been sweeping the world. This has attracted much attention to the mode of aerosol transmission. With the rapid development of large-scale and intensive breeding, microbial aerosols have gradually become the main factor of environmental pollution in animal houses. They not only lead to a large-scale outbreak of infectious diseases, but they also have a certain impact on the health of animals and employees in the houses and increase the difficulty of prevention and control of animal-borne diseases. This paper reviews the distribution, harm, and control measures of microbial aerosols in animal house environments in order to improve people's understanding of them.

Intestinal Flora-Derived Kynurenic Acid Protects Against Intestinal Damage Caused by Candida albicans Infection via Activation of Aryl Hydrocarbon Receptor

Colonization of the intestinal tract by Candida albicans (C. albicans) can lead to invasive candidiasis. Therefore, a functional intestinal epithelial barrier is critical for protecting against invasive C. albicans infections. We collected fecal samples from patients with Candida albicans bloodstream infection and healthy people. Through intestinal flora 16sRNA sequencing and intestinal metabolomic analysis, we found that C. albicans infection resulted in a significant decrease in the expression of the metabolite kynurenic acid (KynA). We used a repeated C. albicans intestinal infection mouse model, established following intake of 3% dextran sulfate sodium salt (DSS) for 9 days, and found that KynA, a tryptophan metabolite, inhibited inflammation, promoted expression of intestinal tight junction proteins, and protected from intestinal barrier damage caused by invasive Candida infections. We also demonstrated that KynA activated aryl hydrocarbon receptor (AHR) repressor in vivo and in vitro. Using Caco-2 cells co-cultured with C. albicans, we showed that KynA activated AHR, inhibited the myosin light chain kinase-phospho-myosin light chain (MLCK-pMLC) signaling pathway, and promoted tristetraprolin (TTP) expression to alleviate intestinal inflammation. Our findings suggest that the metabolite KynA which is differently expressed in patients with C. albicans infection and has a protective effect on the intestinal epithelium, via activating AHR, could be explored to provide new potential therapeutic strategies for invasive C. albicans infections.