Effects Of Different Selenium Sources On Chicken Intestinal Microorganisms Based On High-throughput Sequencing Analysis

Selenium is an indispensable microelement for human beings.It has the functions of enhancing immunity,eliminating free radicals,preventing tumors and liver diseases.Selenium is divided into inorganic selenium and organic selenium.Inorganic selenium mainly refers to sodium selenite,a salt containing selenium,which has greater toxicity and low bioavailability,which is not conducive to the absorption of selenium by humans and animals.Inorganic selenium is very cheap,so it is often added to animal feed,but many countries have banned the addition of sodium selenite to foods.Organic selenium mainly exists in the form of selenium-containing proteins.The most common is selenium from yeast,and nano-selenium and complex selenium newly developed in recent years.Compared with inorganic selenium,organic selenium has low toxicity,high utilization rate,and does not cause environmental pollution,which is more conducive to the body's absorption of selenium.In this study,Pingyao Guoqing Tongying Poultry Industry Co.,Ltd.of Shanxi Province was tested for several physiological and biochemical indicators after 8 weeks of age based on the layers of inorganic selenium,yeast selenium,nano-selenium,and complexed selenium.High-throughput sequencing analysis of intestinal microbial diversity.The conclusions reached are as follows:(1)After 8 weeks of feeding,the selenium deposition rate of eggs fed with yeast selenium was the highest,followed by inorganic selenium,and complex selenium and nano-selenium did not achieve a good selenium-enriching effect.Compared with inorganic selenium,yeast selenium can significantly increase the activity of plasma glutathione peroxidase and reduce the content of plasma malondialdehyde,and has excellent antioxidant effect;nano-selenium is equivalent to improving the antioxidant performance of laying hens or Better than yeast selenium.Yeast selenium can significantly increase the average egg weight without significantly affecting other production performance indicators.Different selenium sources had no significant effect on egg weight,protein height,yolk rate,egg white rate,and egg shell rate.(2)A total of 837,208 valid sequences were obtained by sequencing the fungal ITS,including 313 OTUs.No significant difference was observed in the diversity of the fungal community structure with different selenium sources.The main dominant bacteria were Penicillium,Aspergillus,Fusarium,and Trichoderma.High abundance of Wallemia appeared in complexed selenium group.According to environmental factor correlation analysis,egg selenium deposition,average egg weight,and plasma glutathione peroxidase activity are the main environmental factors affecting the diversity and abundance of fungal communities.After trophic analysis of fungal communities,The dominant fungi are saprophytic.(3)A total of 605,364 valid sequences were obtained by sequencing 16 S r DNA of bacteria,including 501 OUTs.No significant difference was observed in the dominant bacterial populations with different selenium sources,but significant differences were observed in individual less abundant bacteria.Firmicutes,Bacteroidetes,and Actinobacteria are the dominant bacteria.The main dominant bacteria include Lactobacillus and a fungus of Peptostreptococcaceae,Turicibacter,and Aerococcus,the abundance of Trichococcus and Facklamia were significantly different in the 4 groups of samples;the protein height,egg yolk,and plasma malondialdehyde content were The main environmental factors that affect the diversity of intestinal bacterial communities in laying hens.The genes encoded by the intestinal bacteria of laying hens are mainly related to metabolism,and are also affected by genetic information,environment and cellular processes."Transportation and metabolism of amino acids" and "transportation and metabolism of carbohydrates" are the main functional groups of intestinal bacteria in laying hens.