Characteristic cell fragments in bovine milk

Abstract

SummaryPellets produced by the centrifugation of bovine milk and of pre- and post-partum colostrum consistently contained small cell fragments (1–4 μm long) morphologically characterized by their possession of abundant microvilli along one margin. They were more common in strippings than in fore-milk and during the first 4–6 weeks of lactation than at later stages. Their possession of cytoplasmic fat droplets and putative casein micelles suggests that they originate from secretory cells of alveoli or small ducts. The significance of their numerous microvilli is discussed.