Mass administration of antibiotic for the prevention of respiratory disease in calves

• Autores: A.G.V. Teixeira, J.A.A. McArt, R. C. Bicalho
• Localización: Veterinary Record, ISSN-e 2042-7670, Vol. 180, Nº. 8, 2017, págs. 1-2
• Idioma: inglés
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• Resumen

  • Bovine respiratory disease (BRD) is typically initiated by an environmental stressor or a viral infection that weakens pulmonary defence mechanisms, often allowing bacterial colonisation. As grouphoused calf rearing systems become more popular, it is expected that respiratory diseases will become more prevalent during the preweaning period. Otitis and BRD are frequently concomitant diseases, sharing common risk factors and similar pathogens. This study aimed to evaluate the efficacy of two metaphylactic approaches on the prevention of BRD, otitis and mortality in high-risk, group-housed, preweaned Holstein heifer calves.

    The long-acting antibiotic tildipirosin was administered subcutaneously at a dose of 1ml per 45 kg bodyweight for each calf receiving an antibiotic injection. Newborn calves on a dairy farm were assigned to one of three treatment groups: a control group where calves received no treatment; a group where calves received one antibiotic injection at 10 days old; and a group where calves received two antibiotic injections, the first at 10 days old and the second at 35 days old. All study heifers (n=795) were reared in group pens of 25 calves per pen and fed unrestricted milk from day 1 to day 65.

    Statistical models were used to evaluate the effect of treatment on mortality, BRD and otitis, as well as average daily weight gain.

    Metaphylactic treatment with tildipirosin had no effect on the incidence of BRD alone, otitis alone, mortality or average daily weight gain in dairy heifers during the preweaning period. When evaluating the combined incidence of BRD and/or otitis, tildipirosin metaphylaxis was associated with a significant reduction in disease incidence.

    The authors conclude that long-acting antibiotic metaphylaxis could be used strategically to decrease the combined incidence of BRD and/or otitis in high-risk, group-housed heifers during the preweaning period.