Seasonal prevalence (%) of the most frequent combinations of Top 7 serogroups detected by PCR from pooled samples of cattle feces collected at delivery to slaughter (n = 1,749). StanfordKim P. JohnsonRoger W. AlexanderTrevor McAllisterTim A. ReuterTim 2016 <p>Seasonal prevalence (%) of the most frequent combinations of Top 7 serogroups detected by PCR from pooled samples of cattle feces collected at delivery to slaughter (n = 1,749).</p>