Immune components of bovine colostrum and milk1

Abstract

Colostrum and milk provide a complete diet for the neonate. In ruminants, colostrum is also the sole source of initial acquired immunity for the offspring. Milk therefore plays an important role in mammalian host defense. In colostrum, the concentration of immunoglobulins is particularly high, with IgG being the major immunoglobulin class present in ruminant milk, in contrast to IgA being the major immunoglobulin present in human milk. Immunoglobulins are transported into mammary secretions via specialized receptors. In addition to immunoglobulins, both colostrum and milk contain viable cells, including neutrophils and macrophages, which secrete a range of immune-related components into milk. These include cytokines and antimicrobial proteins and peptides, such as lactoferrin, defensins, and cathelicidins. Mammary epithelial cells themselves also contribute to the host defense by secreting a range of innate immune effector molecules. A detailed understanding of these proteins and peptides offers great potential to add value to the dairy industry. This is demonstrated by the wide-ranging commercial applications of lactoferrin derived from bovine milk. Knowledge of the immune function of milk, in particular, how the gland responds to pathogens, can be used to boost the concentrations of immune factors in milk through farm management practices and vaccination protocols. The latter approach is currently being used to maximize yields of bovine milk-derived IgA directed at specific antigens for therapeutic and prophylactic use. Increasingly sophisticated proteomics technologies are being applied to identify and characterize the functions of the minor components of milk. An overview is presented of the immune factors in colostrum and milk as well as the results of research aimed at realizing this untapped value in milk.

Characteristics of mammary secretions from Holstein cows at approximately 10 days before parturition: with or without intramammary infection

“…In secretions of intermediate viscosities, the serum albumin concentrations were apparently higher than those of thick viscosities. Increased serum albumin concentrations in mammary secretions may occur through the influx of the protein through leaky tight junctions, which are caused by increased permeability of capillary vessels during mastitis (Stelwagen et al 2009;Lehmann et al 2013). The serum albumin concentrations in the mammary secretions were highly correlated with viscosity of the mammary secretions.…”

“…Increased infiltration of IgG 1 passively transferred in the mastitic mammary secretions via leaky tight junctions (Stelwagen et al 2009;Lehmann et al 2013), in addition to the inherent high variation in the IgG 1 concentration, could be the likely causes.…”

Colostrum from Different Animal Species – A Product for Health Status Enhancement

“…Immunoglobulins are transferred right after parturition from colostrum to the newborn for animals such as bovine, goat, ovine, equine; while for humans immunoglobulins are transferred via the placenta to the newborn baby right after birth (Muller and Ellinger, 1981 citated by Pandey et al, 2011;Stelwagen et al, 2008).…”

Acute phase proteins and their use in the diagnosis of diseases in ruminants: a review

“…The concentrations of lactoferrin in milk vary from 1.15 to 485.63 µg/ml in healthy cows; however, its levels can rapidly increase in cows with subclinical and clinical mastitis and its concentrations are positively correlated with SCC, stage of lactation, and milk yield (Kawai et al 1999;Hagiwara et al 2003). Lactoferrin concentrations are higher in colostrum (varying between 1 mg/ml and 5 mg/ml), and during drying off and the early mammary involution period than during lactation (Kutila et al 2003;Stelwagen et al 2009). …”