The ARS-BFGL-NGS-50482 SNP which tended to be associated with pneumonia incidence in the combined beef-suckler and dairy calf population was closest to a gene, CXCR4, which was observed to have lower gene expression at 48 h post-birth in the serum of dairy calves (tube fed 5% of their body weight in colostrum, within one hour of birth) and Limousin-Friesian beef-suckler calves (that suckled their dams naturally, within one hour of birth) compared with 0 h (at birth)22. Here, CXCR4 is linked to pneumonia.