Average neutralising antibody titres against A Turkey 14/98 observed in serum samples from calves vaccinated with monovalent A Turkey 14/98 vaccine (red) or with A
Iraq vaccine (blue) and from the non-vaccinated calves with maternal antibodies (green). The average neutralising antibody titres of the groups with maternal antibodies (group 1, 2 and 3) are shown with a solid line. The average neutralising antibody titres of the calves without maternal antibodies (group 4 and 5) are shown a dashed line. The bars represent the standard error of the mean; to prevent overlapping error-bars the lines are slightly displaced.