| In recent year, the upward trend of milk cow abortion, abortion rate is as high as 12.3%, which caused serious economic losses to the dairy industry. Detect pathogen of dairy cow abortion, analysis of reasons, has important significance to the prevention and control of milk cow abortion.Through the investigation of each cow farms in Luoyang(District) found that some dairy abortion rate is as high as 20%.The largest number of cows abortion in the 2-4 embryo, abortion rate is as high as 17.22%~25.18%; abortion cow concentrated in April, June, July, October, accounting for 52.24% of the total abortion number(256/490), abortion rate is as high as 18.56%~23.67%; cow abortion in all stages of pregnancy, but often occured at 110~170d of pregnancy dairy, accounting for 47.14% of the total abortion number(231/490).In order to detect the major pathogens that cause the abortion of cow in Luoyang area, from 2013 July to 2015 March, collected in the area of dairy farms(District) a total of 42 fresh abortive fetal bovine head, and maternal blood, vaginal secretion and nasal secretions, plan for 42 samples, test Neospora caninum, Toxoplasma gondii, Tritrichomonas foetus, Brucella abortus, IBRV, and BVDV of 6 kinds of pathogen nucleic acid common abortion by PCR or RT-PCR method. The result showed the total infection rate was 42.9%(18/42), the N. caninum infection rate was the highest, 40.5%(17/42); the second was IBRV, 11.9%(5/42); T. foetus, B. abortus, T. gondii and BVDV infection rates were 2.4%, 2.4%, 2.4% and 14.3%(6/42) of the samples were mixed infection, and large number was the N. caninum +IBRV mixed infection(50%, 3/6). Combined with the detected in abortion dairy cattle feeding and management of the clinical characteristics and other factors, concluded that N. caninum is the main pathogen of bovine abortion in the region.In order to know the infection of Neospora caninum in this area, collect the cow serum or had a history of abortion, detect N. caninum antibody by indirect ELISA. The result showed, the average antibody positive rate of N. caninum in this area was 44.44%(88/198); the antibody positive rate of N. caninum of scale farms was 47.06% higher than the small farmers(41.67%); the antibody positive rate of N. caninum abortion dairy cattle was 58.97% higher than the normal cows was 40.88%; the highest antibody positive rate of N. caninum was 53.12% in the second parity; the highest antibody positive rate of N. caninum was 48.84% at the age of 3. The results also confirm that the larger number of cow abortion in Luoyang area is caused by N. caninum.The dog is the final host of Neospora caninum, the dog of cow farms(District) with the high infection rates of N. caninum are closely. This experiment to collect the fresh feces of the dog from the farms(District) of higher abortion rate, detect N. caninum oocysts from the faeces of dog by saturated sucrose flotation, identify suspected N. caninum oocysts by the measure of PCR. Results showed that, in the 12 fresh feces collecting, detected 3 cases of N. caninum, the results confirmed that the dog and high infection rate of N. caninum are closely. The results of this study will provide scientific basis for effective prevention and control bovine abortion in this region,... |
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