Studying the prevalence of Holstein cow herd with anti-Neospora caninum antibodies in the bulk milk of Garmsar and related reproductive indices

In order to determine the sero-epidemiological prevalence of Neospora caninum in Garmsar, in this study, bulk milk samples were prepared for ELISA testing from 72 large herds of dairy cows in Garmsar city (about 10% of all livestock farms in this city). Also, serum samples of 11 dog belonging to herds with positive blood samples were taken and sent to the laboratory to be analyzed by ELISA kit. The findings showed that in 55 farms (75.4%) the results of the ELISA test were positive. In 11 samples taken from herd dogs, positive results were shown in 9 dogs. The geographical region of sampling, livestock population in the herds, parturition to pregnancy interval, pregnancy and the conception did not differ between ELIZA positive and negative herds. (P>0.05). The average number of female calves in the negative ELISA herds was 2 and in positive ELISA was 3 (P=0.01). The mean rate of herd pregnancy in positive ELISA herds was 50% and in negative ELISA herds was 45% (P>0.05). Also, the average milk production per cow was 27.8 kg in negative herds and 26.9 kg in positive herds (P=0.026). The correlation between the presence of dogs and the spread of this parasite was confirmed by Pearson's and Spermman's correlation tests. (P=0.00, r=0.47). It was concluded that in Garmsar city, 75.4% of the bulk milk of the examined herds had a positive ELISA result, and the amount of milk production in these positive herds was less and the presence of dogs was more.