Randomized trial assessing the effect of two types of multivalent intranasal vaccine at birth on respiratory disease, mortality and average daily gain in preweaned Holstein heifers

Intranasal vaccination soon after birth is a common protocol used on many dairy farms with a goal of reducing preweaning respiratory disease. Although several studies have assessed antibody titers post-intranasal vaccination, few have assessed clinically relevant outcomes. No studies have compared the effi­cacy of intranasal vaccination against viral agents with intrana­sal vaccination against viral and bacterial agents. Our objective was to assess the effect of these 2 types of intranasal vaccine products against a non-vaccinated control group on respiratory disease, mortality, and ADG in preweaned heifers.