Supplementary table 1

BVDV is a productive and reproductive virus that causes great economic impact in dairy production systems. This study occurred in partnership with USP and Frisia Agroindustrial Cooperative, with costs subsidized by the More Healthy Milk Program (MAPA). The aim of this abstract is to present the epidemiological data of BVDV infection in the Campos Gerais region of Paraná. Milk tank samples were collected from 289 cooperative farms from August 2020 to January 2022, to investigate BVDV infection at herd level through qPCR. Out of these farms, 68 were selected by convenience to search for persistently infected females (PI) through antigen ELISA test from ear tissue. The target population was composed of the herd's last generation, females that gave birth to males and stillbirths. It was recommended to repeat the tests on positive animals, with a minimum interval of 21 days, in addition to testing the dams and granddams. According to the results of tests, the herds were divided into four categories: 1 - Negative for both tests; 2-qPCR positive and ELISA Ag negative; 3-qPCR negative and ELISA Ag positive and 4-Positive for both. In all, 2,902 qPCR and 23,466 antigen ELISA tests were performed. Thus, 76.12% (220/289) of the properties were considered negative and 23.87% (69/289) positive in at least one qPCR test. To PI survey, 41.17% (28/68) of the farms had at least one positive result for ELISA Ag, while 58.83% were negative. 41.17% (28/68) properties were considered free of BVDV (category 1); 17.64% (12/68) in category 2; 13.23% (9/68) in category 3 and 27.94% (19/68) were truly classified positive - category 4. Regarding vaccination practices, 62 of the 68 properties: 72.58% (45/62) of the producers vaccinated against reproductive viruses and 27.41% (17/62) did not vaccinate. Five producers (8.06%; 5/62) reported the use up to two different brands for vaccination of reproductive diseases, depending on market availability. Only 4 (4/62, 6.45%) used modified live vaccines. The frequency of vaccine management ranged from 1 to 4 times a year. This epidemiological survey demonstrates the importance of implementing control programs against BVDV, which includes biosecurity practices and review of vaccination protocols.