Effect Of Swine Farm Wastewater On Waterfowl Intestinal Health And Microflora And Metabolome

With the rapid development of modern agricultural economy and the increasing improvement of people’s living standards,the demand for livestock products is also increasing.China’s farming waste resource utilization is not high,resulting in a more serious livestock and poultry farming waste pollution problems.Pig farm pollution problems are mainly manifested in water pollution,air pollution,disease transmission,the production of NH₃,H₂S,CH₄and other toxic and harmful gases.As an important waterfowl,meat ducks are inevitably exposed to wastewater polluted by swine farm wastewater,and there are few studies on the effects of swine farm wastewater on meat duck organism.The intestine is the largest digestive organ of the organism and one of the organs that has the most contact with the outside world.Since the intestine is colonized by countless microorganisms and continuously exposed to them,and at the same time the intestine,as a digestive organ,is frequently exposed to the external environment,thus it will inevitably lead to microflora imbalance due to foreign antigens and microorganisms,which will have certain effects on the growth and development of the organism.In order to study the effects of swine farm wastewater on the growth index,intestinal microbiota and metabolism of ducks,60 ducks were reared under conventional feeding conditions and randomly divided into a control group（Con group=30）and a test group（Sew group=30）at the age of 1 day,with ducks in the control group drinking normal water and ducks in the test group drinking swine farm wastewater,and ducks in both groups were provided with sufficient and identical feed daily and fed freely.The average daily feed intake,body weight and organ index were recorded during the experiment,and histomorphological,intestinal microbiomics and metabolomics were used to evaluate the changes in liver,kidney,duodenum and ileum histomorphology as well as intestinal microorganisms and metabolites in the ducks.The results obtained were as follows.1.After 14 days of experimental treatment,the body weight,average daily feed intake,liver,heart,kidney,spleen,thymus and bursa of the meat ducks were recorded,and after analysis,it was found that the difference between the body weight of the meat ducks in the control group and the meat ducks in the swine farm wastewater group was highly significant（P<0.01）;the feed intake of the meat ducks in the control group increased regularly with the increase of day age,and the feed intake of the swine farm wastewater group was not regular;the liver of the meat ducks in the control group index was highly significant higher than that of the swine farm wastewater group（P<0.01）,and the organ indices of heart,kidney,spleen,thymus and bursa phalloides were not significantly different between the two groups（P>0.05）.2.HE staining microscopy revealed that the liver and kidney tissues of the control duck were clear with no lesions,while the central veins of the liver of the wastewater group were dilated and the hepatocytes were not neatly arranged;the epithelial cells of the kidney tubules of the wastewater group were pigmented and infiltrated with lymphocytes;the intestinal villi of the duodenum and ileum of the control duck were finger-shaped and neatly arranged,while the intestinal villi of the duodenum and ileum of the wastewater group were not finger-shaped and the edges of the structures were not In the control group,the intestinal villi of the duodenum and ileum were finger-shaped and neatly arranged.3.Using 16s sequencing,a total of 1473908 OTUs were obtained,with more original sequences and valid sequences in the control group than in the pig farm wastewater group.There were 79 unique OTU aggregates in the control group and 78 unique OTU aggregates in the swine farm wastewater group,with a total of 760 aggregates.There were no significant differences between the two groups in Good’s coverage,Chao1,ACE,Shannon and Simpson indices by alpha and beta diversity analysis.Analysis of their phylum genera showed that a total of 33 phyla and 414 genera were detected in both groups,with 11 to 27 phyla and 138 to 281 genera per sample.In both groups,the most predominant bacteria in the phylum were the thick-walled facultative bacteria,the phylum Aspergillus,the phylum Actinomycetes and the phylum Synechococcus.4.Metabolomic analysis of their intestinal contents showed that there were significant differences in metabolites between the Con and Sew groups;37differential metabolites were screened between the two groups under positive and negative ion pattern screening;enrichment of metabolic pathways showed that eight metabolic pathways were significantly different between the two groups in summary;analysis of differential metabolizing bacteria and metabolite associations showed that glutathione was associated with Chlamydomonas spp.and The analysis of differential metabolism bacteria and metabolite associations showed that glutathione was positively correlated with Bacillus galloprovincialis and Bacillus citric acidophilus,but negatively correlated with Rothschildia spp.In conclusion,this experiment found that the healthy meat ducks after drinking pig farm wastewater treatment had slow weight gain,disturbed intestinal flora and differences in metabolites.The results of this study have some reference value for controlling the pollution treatment of large-scale pig farm wastewater,and provide some theoretical support for the prevention and treatment of waterfowl infected with diseases due to pig farm wastewater.