An outbreak of H5N1 highly pathogenic influenza A virus (HPIAV) has been detected in dairy 20 cows in the United States. Influenza A virus (IAV) is a negative-sense, single-stranded, RNA 21 virus that has not previously been associated with widespread infection in cattle. As such, cattle 22 are an extremely under-studied domestic IAV host species. IAV receptors on host cells are 23 sialic acids (SAs) that are bound to galactose in either an α2,3 or α2,6 linkage. Human IAVs 24 preferentially bind SA-α2,6 (human receptor), whereas avian IAVs have a preference for α2,3 25 (avian receptor). The avian receptor can further be divided into two receptors: IAVs isolated 26 from chickens generally bind more tightly to SA-α2,3-Gal-β1,4 (chicken receptor), whereas 27 IAVs isolated from duck to SA-α2,3-Gal-β1,3 (duck receptor). We found all receptors were 28 expressed, to a different degree, in the mammary gland, respiratory tract, and cerebrum of beef 29 and/or dairy cattle. The duck and human IAV receptors were widely expressed in the bovine 30 mammary gland, whereas the chicken receptor dominated the respiratory tract. In general, only 31 a low expression of IAV receptors was observed in the neurons of the cerebrum. These results 32 provide a mechanistic rationale for the high levels of H5N1 virus reported in infected bovine 33 milk and show cattle have the potential to act as a mixing vessel for novel IAV generation