aCentro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Portugal bLaboratório Pfizer – Saúde Animal, Lisboa, Porto Salvo, Portugal cUnidade de Recursos Genéticos, Reprodução e Melhoramento Animal – INRB, Vale de Santarém, Portugal
We investigated the effect of vaccination of male beef calves (mean age ± S.D.: 158 ± 31days) against bovine herpes virus (BHV-1 or IBR virus), bovine respiratory syncitial virus (BRSV), bovine viral diarrhea (BVD) virus and para-influenza (PI3) virus on the incidence of respiratory disease during the first forty days after weaning and entering a feed-lot in Portugal.
In May 2003, Mertolenga, Preta and mixed-breed calves from 10 different beef herds, were systematically assigned (by order of entrance in a chute) to two treatment groups, before moving to a common feed-lot. One hundred and twenty five male calves were vaccinated with a quadrivalent vaccine (Rispoval 4®) and revaccinated after 21–27 days while 148 herdmates were injected with saline (0.9% NaCl) on the same occasions. The incidence and severity of clinical cases of “bovine respiratory disease” (BRD) were evaluated every day during the first 40 days after entering the feed-lot. Morbidity (3% vs. 14%) and mortality (0% vs. 4%) due to BRD were significantly lower in the vaccinated group. Ten days after revaccination, the calves were treated with an antimicrobial – ending the study – after an outbreak of BRD caused a high incidence of disease in the non-vaccinated group.
In conclusion, our results showed that Rispoval 4®, a quadrivalent vaccine against respiratory viruses, under field conditions, reduces morbidity and mortality due to BRD in beef calves after weaning.
This article was published in Preventive Veterinary Medicine, 72, George Stilwella, Miguel Matosb, Nuno Carolinoc and Miguel S. Limaa, Effect of a quadrivalent vaccine against respiratory virus on the incidence of respiratory disease in weaned beef calves, 151-157, Copyright Elsevier 2008.