Juan José Romero Zúñiga

1. IntroductionReducing the production costs is becoming more important in the dairy industry. The suitable development of replacement heifers is an expensive investment for dairy farms, so estimations of all associated costs are about 20% of the total production costs [1].The age at first calving (AFC) reflects the rate of growth of the female. A late entry in the productive life reduces the econ ...

IntroductionAs any other Latin American country, bovine brucellosis is a significant animal health problem and a relevant zoonosis in Costa Rica (CR). Consequently, the disease is of veterinary and of public health relevance. Bovine brucellosis (then recognized as “Bang´s disease”) was clinically described in the Central Valley and in the volcanic highlands at the end of the XIX ...

INTRODUCTIONBovine viral diarrhea virus (BVDV) has been classified within the genus Pestivirus of the family Flaviviridae (Wengler et al., 1995). It has a positive single-stranded RNA genome of approximately 12.3kb size, encoding one open reading frame (ORF) that is translated into a single polyprotein of about 4000 kDa (Collett et al., 1988; Meyers and Thiel, 1996). The polyprotein is subsequentl ...