The study was carried out with an aim for detection of protozoan aetiology for infertility in cross bred cattle using conventional and molecular tools in Rayalaseema region, Andhra Pradesh. Blood and cervico-vaginal swabs of 85 crossbred cattle above 3 years of age with and without pyrexia and with the history of infertility/abortion and ten brain, sixteen liver tissue samples of aborted foetuses collected were subjected for the detection of Theileria annulata, Anaplasma marginale, Trypanosoma evansi, Neospora caninum and Tritrichomonas foetus using Giemsa and Acridine orange staining techniques and species specific PCR.The overall prevalence of blood parasites was 17.6% by Giemsa staining with highest incidence of T. annulata (7.0%), A. marginale (5.8%) and T. evansi (4.7%) where as Acridine orange staining showed 36.4% with highest prevalence of T. annulata (15.2%), A. marginale (14.1%) and T. evansi (7.0%). PCR was standardized for detection of T. annulata, T. evansi and A. marginale, out of 85 blood samples subjected to PCR, 45 (52.9%) were found positive for blood parasites, at 25.8% (22/85), 20.0% (17/88) and 7.0% (6/85) were positive for A. marginale, T. annulata and T. evansi, respectively. The Nested PCR was found to be sensitive than primary PCR in detection of A. marginale. Blood parasites prevalence was higher in H.F cross (58.8%) and the animals with pyrexia (68.0%). The study indicates the marginal role of protozoan parasites in inducing infertility of cross bred cattle.

Highlights

• Higher prevalence of A. marginale, T. annulata and T. evansi with infertility and abortions.
• Blood parasites detection using PCR was more sensitive than conventional methods.
• Semi-nested PCR was twice more sensitive than primary PCR assay in detection of A. marginale.