ABSTRACT
Abortion in dairy cattle is generally defined as the loss of fetus on days 47-265 of pregnancy and can significantly reduce the income and capital gain of farmers and producers. Therefore, sufficient economical support and preventive measurements are essential for this issue. In this study, genetic materials were extracted from the abomasum rennet, as well as homogenous preparations of brain, kidney, spleen, liver, and lung tissues of 128 aborted fetuses. Afterward, polymerase chain reaction (PCR) and Reverse Transcription Polymerase Chain Reaction (RT-PCR) tests were performed to identify the bovine viral diarrhea virus (BVDV), bovine herpesvirus 1 (BHV-1), Neospora caninum parasite, and serovars of Leptospira species. In the PCR test, the samples with 380 bp, 340 bp, and 173 bp bands were considered as positive for serovars of Leptospira, Neospora caninum, and BHV-1, respectively. Moreover, a 290 bp band was regarded to be BVDV in the RT-PCR. According to the findings of the current study, 39 (30.47%) of the samples were infected with Neospora caninum, 26 (20.31%) with BVDV, 17 (13.28%) with BHV-1, and 18 (14.06%) with serovars of Leptospira. In addition, multiple-agent infections were also detected in the samples. As a conclusion, the microorganism Neospora caninum was identified as the most prevalent infectious cause of abortion in the eight agro-industrial and livestock complexes, in Qazvin province, Iran.
