| Bovine endometritis is a common gynecological disease, which is mainly caused by postpartum bacterial infection. It resulted in prolongation of calving, decreased milk production, reduced in milk quality, and caused serious economic losses to the dairy industry. Therefore, the diagnosis and treatment of endometritis, screening the resistance genes are particularly important. Cow endometritis is affected by genetic and environmental influences, so the condition is different in various regions. This study is divided into three parts, the first part is the investigation of cow endometritis for Jiaxian Red cattle and the cows in parts of Henan province. The second part is for the laboratory diagnosis for bovine endometritis, including the isolation and identification of bacteria from the bovine uterine contents, blood physiological and biochemical diagnosis and high-throughput sequencing for 16 S r DNA from bovine uterine contents. The third part is analysis the differential genotype frequency in whole genome between the cows in parts of Henan province and the Jiaxian Red cattle by using the simplified sequencing technical analysis, and the candidate resistance gene of endometritis cows was selected, which will provide the basis information for the efficient breeding of cow and for the establishment of the genetic library of molecular marker. The results of this study are as following:1. The epidemiological investigation showed that bovine endometritis was caused by mixed-infection, the main pathogenic microorganisms were Escherichia coli, Staphylococcus aureus, Bacillus cereus. The pathogenic microorganism types were varied from different farms, the incidence of bovine endometritis occured from May to October were significant difference(P < 0.05) when compared to that in January and Febrary, while the accident rates of bovine endometritis in the months of May to October were no significance(P > 0.05). The analysis of the incidence of endometritis and parity relationship showed that there is significant difference for the positive rate between the 2-6 and the first fetal(P < 0.01), and there is no difference of the endometritis incidence rate between the second to sixth fetal(P > 0.05).2. Analysis the physiological and biochemical indexes of blood showed that the number of white blood cells of dairy cows with endometritis was higher than that of the reference range when compared with the normal dairy cows(P < 0.01), while white blood cell proportion was changed when compared with the normal group. The neutrophil percentage of endometritis cow was increased significantly(P < 0.05), the absolute value of neutrophil slao increased(P < 0.01). The percentage of lymphocytes decreased significantly(P < 0.01), but the absolute value of lymphocyte did not change significantly(P > 0.05). The number of red blood cell, the mean corpuscular volume and hematocrit in endometritis group was not change too much(P > 0.05) when compared with that of the normal group of dairy cows, but the average red blood cell volume was below in the reference range. The concentration of hemoglobin and mean corpuscular hemoglobin was significantly difference(P < 0.05) between the endometritis group and the normal group, and mean corpuscular hemoglobin was significantly difference(P < 0.01). Blood biochemical analysis showed that the indexes of ALP and ALT associated with liver function decreased, while AST increased, but there is no significant difference(P > 0.05). Total nitrogen was decreased significantly(P<0.05), total protein and the content of albumin decreased, but the change was not significant(P > 0.05). Ca and P index correlated with renal function were decreased significantly(P < 0.05). There was no significant change for the creatinine glucose and urea nitrogen(P > 0.05).3. The sequencing results showed that, there are different types of dominant bacteria in different groups. Although in the same pasture, the dominant bacteria are different compared with the individuals by the same symptoms. The abundance of bacteria the top 10 Phylum respectively is Firmicutes, Proteobacteria, Bacteroidetes, Tenericutes, Fusobacteria, Actinobacteria, Verrucomicrobia, Thaumarchaeota, Gemmatimonadetes, Acidobacteria. The top genera as follows: Trueperella, Bacteroides, Porphyromonas, Streptococcus, Helcococcus, Fusobacterium, Ruminococcaceae_UCG-005,Moraxella.4. In the epidemiological investigation of endometritis, we found that in the similar feeding and management conditions, the endometritis incidence in Jiaxian Red cattle was significantly lower than that of cows, which suggested that the genetic differences between Jiaxian Red cattle and cows may affect the incidence of endometritis. Using the specific-locus amplified fragment sequencing(SLAF-seq) to screen the differential gene of whole genome by testing the blood samples in Jiaxian Red cattle and Zhengzhou surrounding dairy cows. Two genes that maybe associate with the endometritis candidate resistance gene, interleukin receptor protein competition(IL1RAP), was selected from the whole genome between Chinese Holstein cow and the Jiaxian Red cattle. Through the analysis of the population differentiation information between Jiaxian Red cattle and cow, eight endometritis-resistance chemokines that may affect Jiaxian Red cattle and cows were found. These chemokines are IL8, CXCL5, CXCL2, CXCL3, CXCL9, CXCL10, CXCL11, CXCL13. But for the relation between these genes and the resistance of endometritis, we did not know currently, it needs further experiments to confirm.. |
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