739 Braz. J. vet. Res. anim. Sci., São Paulo, v. 43, n. 6, p. 739-746, 2006 Reproductive rates and performance traits in beef cattle infected by Bovine Herpesvirus Claudia DEL FAVA 1 Edviges Maristela PITUCO 1 Leopoldo Andrade de FIGUEIREDO 2 Alexander George RAZOOK 2 Joslaine Noely dos Santos Gonçalves CYRILLO 2 José Victor de OLIVEIRA 3 Roberto Hauck REICHERT 4 José Luiz D´ANGELINO 5,6 1 - Centro de Pesquisa e Desenvolvimento de Sanidade Animal do Instituto Biológico da Agência Paulista de Tecnologia dos Agronegócios, São Paulo - SP 2 - CAPTA Bovinos de Corte do Instituto de Zootecnia da Agência Paulista de Tecnologia dos Agronegócios, Sertãozinho - SP 3 - APTA Regional – PRDTA Alta Mogiana, Colina - SP 4 - APTA Regional – PRDTA Vale do Ribeira, Registro - SP 5 - Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, São Paulo - SP 6 - Faculdade de Medicina Veterinária da Universidade de Santo Amaro, São Paulo - SP Abstract Reproductive rates and performance traits in beef cattle females infected by Herpesvirus Bovine–1 (BoHV-1) were evaluated in a farm at São Paulo state, Brazil. Gir, Guzerá, Nelore and Caracu purebred animals were examinated to BoHV-1 (ELISA) at the beginning of the breeding season and the occurrence of reactors was 54.2% (386/712). BoHV-1 did not interfere in the pregnancy rates of both reagent - 80.3% (310/ 386) and non-reagent - 74.5% (243/326) females. It did not reduce the parturition rate of both reagent - 97.7% (300/307) and non- reagent - 93.8% (225/240) females. Total rate of stillbirths in BoHV- 1 reagent females - 1.3% (4/300) did not differ from non-reagent females - 2.2% (5/225). BoHV-1 did not affect performance traits for reagent and non-reagent females, respectivelly, to daily weight gain during the breeding season (459.90 ± 2.82 g and 466.63 ± 2.87 g), body condition score at the beginning of the breeding season (6.89 ± 0.08 and 6.99 ± 0.08), body condition score at the end of the breeding season (7.73 ± 0.06 and 7.71 ± 0.06), weight at parturition (419.17 ± 3.34 kg and 425.97 ± 3.22 kg). It was concluded that non-vaccinated beef cattle females infected by BoHV-1 and bred under adequate extensive management, with body condition score over 5 and gain of weight during the breeding season presented good pregnancy, parturition and birth rates, no matter the breed, genetic group, age and seroconvertion. Correspondence to: CLAUDIA DEL FAVA Centro de Pesquisa e Desenvolvimento de Sanidade Animal Instituto Biológico Agência Paulista de Tecnologia dos Agronegócios Av. Conselheiro Rodrigues Alves, 1252 04014-002 - SãoPaulo - SP delfava@biologico.sp.gov.br Received: 28/03/2005 Accepted: 13/02/2006 Key-words: Bovine Herpesvirus 1. Beef Cattle. Zebu breeds. Reproductive. performance. Performance traits. Introduction Bovine infectious rhinotracheitis / infectious pustular vulvovaginitis (IBR/IPV), caused by Bovine Herpesvirus type 1 (BoHV-1) 1 is a virosis that affects the respiratory and reproductive systems. Its economic impact can be not only observed in the losses it causes in infected animals, but also in the restrictions to the international trade of animals and animal products 2 . Infected bovines are carriers of BoHV-1 for their entire life and the virus remains in neurons of the trigeminal and sacral ganglions, in a non-infectious or latent form. It may be reactivated when animals are exposed to predisposing stressful events that decrease their immunological resistance, such as transportation, treatment with glucocorticoids and calving 3 . Carriers may reactivate and eliminate viral particles, most of the times without presenting clinical signs 4,5,6 . In pregnant cows, viremia may lead