Jorge A. Guccione and Juan J. Guccione were supported by UBACyT 20020150100153BA (UBA) and PIP 11220110100800CO (CONICET). This work was supported by CONCYTEC-FONDECYT within the framework of the contest ?Proyectos de Investigaci?n B?sica 2020-01? [contract number 120-2020-FONDECYT].

Bovine herpesvirus type 1 (BoHV-1) and bovine leukemia virus (BLV) are among the most important pathogens affecting dairy cattle, causing significant economic losses worldwide. The present study determined the seroprevalence of IBR (Infectious Bovine Rhinotracheitis) and BLV in dairy herds in Cajamarca, Peru. A total of 464 animals were sampled, and the presence of antibodies against BoHV1 and BLV was determined using commercial indirect enzyme-linked immunosorbent assay (I-ELISA) kits. Among the sampled animals, the overall seroprevalence was 8.84% (95% CI: 0.5–35.12) for BoHV1 and 7.54% (95% CI: 5.13–9.95) for BLV. The highest BLV seroprevalence was observed in Cajamarca (23.68%), while no positive cases were detected in four provinces. Regarding BoHV1 seroprevalence, it was highest in Cajamarca (26.32%) and Santa Cruz (28.13%), with no cases detected in five of the ten provinces e...

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Background: Cow's milk β-casein has multiple genetic variants, the two most common of which are A1 and A2, which are encoded by the CSN2 gene. Evidence suggests that the A1 variant may negatively affect human health. Type A2 milk is a safer alternative for human consumption because it is easier to digest than A1. Aim: To determine the frequency of the A1 and A2 alleles of the β-casein gene in cattle. Methods: Blood samples were collected from 103 cattle (26 males and 77 females), 71 crossbred, 30 Simmental, 1 Jersey, and 1 Holstein. The selection prioritized females due to their economic value for milk production, reproductive potential, and capacity to replace cows of high genetic value, whereas males are intended for sale for meat production. Analysis of the A1 and A2 alleles of exon 7 of the CSN2 gene was carried out by polymerase chain reaction-restriction fragment length polymorph...