Comparisons of Colostral and Serum Antibody Titres in Cows Vaccinated with E. coli K99 Antigens

Abstract

A field trial was conducted on a large dairy farm to evaluate the serum and colostral antibody responses to four commercially available enterotoxigenic E. coli (ETEC) diarrhea vaccines. Multiparous cows (n= 192) and 114 first calf heifers were randomly assigned to six treatment groups (Table 1). Groups A-D were vaccinated twice subcutaneously; the first dose 50-90 days prior to the expected calving date (at drying off); the second dose three weeks prior to calving. Group E was vaccinated only once at three weeks prior to calving and Group F served as the non-vaccinated controls. It was found that all of the commercially available vaccines tested in this field trial increased colostral and serum antibodies against ETEC. Calf performance or challenge studies were not done because of the sheer numbers of animals and that was beyond the scope of this trial. It also appears that a single vaccination using Coli-bovis at 2-3 weeks pre-partum will produce protective antibody levels in colostrum.