The Protein Component of Sow Colostrum and Milk

Abstract

The production of colostrum and milk by the sow are primary limiting factors affecting survival, growth and development of the piglets. The proteins of colostrum and milk provide not only a supply of amino acids to the neonate but also a wide range of bioactive factors. Proteins in sow mammary secretions include those associated with the milk fat membranes, caseins, mammary-derived whey proteins, immunoglobulins, hormones and growth factors, enzymes, and a wide range of other proteins. Concentrations of most milk-specific proteins typically are lower in colostrum than in milk, while concentrations of immunoglobulins and other bioactive proteins often are enriched in colostrum compared with mature milk. Dietary protein is utilized for milk protein production with approximately 50% efficiency. During both the colostrum period and at peak lactation as much as 700-800 g of protein is secreted daily by today's highly prolific sows. Estimates of daily milk protein secretion during lactation suggest that sows are not able to consume sufficient dietary protein and energy to account for output of solids in milk and therefore must mobilize body protein and body fat to support their milk production. Milk protein content typically is not affected by dietary treatment, indicating that the sow mobilizes her body reserves to maintain milk production and milk protein production. These observations are of particular interest for today's highly prolific sows, which may require more dietary protein than previous genotypes.

Recent progress of porcine milk components and mammary gland function

“…After uptake of free amino acids from blood into the porcine mammary gland, they are synthesized into milk protein, including caseins and whey proteins. The caseins in porcine milk contain α S1 -casein (CSN1S1), α S2 -casein (CSN1S2), β-casein (CSN2), and κ-casein (CSN3) [ 91 ]. It has been demonstrated that CSN2 , CSN1S1 and CSN1S2 are the most abundant three genes related to protein synthesis in the porcine mammary gland [ 92 ].…”

“…It has been demonstrated that CSN2 , CSN1S1 and CSN1S2 are the most abundant three genes related to protein synthesis in the porcine mammary gland [ 92 ]. Except for caseins, the remaining proteins are whey proteins, which are mainly composed of β-lactoglobulin (BLG), α-lactalbumin (LALBA) and whey acidic protein (WAP) [ 91 ]. The possible mechanism of the amino acid transporter and protein synthesis system is summarized in Fig.…”

Effect of Parity on Reproductive Performance and Composition of Sow Colostrum during First 24 h Postpartum

“…Colostrum and milk production by the sow are primary limiting factors affecting the survival, growth and development of newborns. Both secretions are complex biological fluids that contain a number of nutrients as well as protective factors, such as macro- and micronutrients, vitamins and bioactive substances (immunoglobulins, enzymes and growth factors), which play an important role in early gastrointestinal development [ 2 ].…”

“…Hurley [ 1 ] showed that the IgG content of the colostrum decreased to 4.8% of its original concentration at 72 h post farrowing and Frenyo et al [ 4 ] found that it decreased to 3.2% of its original concentration at the fifth day of lactation. Colostrum also has more bioactive components [ 5 ], while milk contains more casein and serum proteins [ 2 , 5 ]. The first secretions from the mammary gland after farrowing are largely absorbed by piglets and appear in their blood within a few hours of secretion from the udder [ 1 ].…”

Inclusion of Oat and Yeast Culture in Sow Gestational and Lactational Diets Alters Immune and Antimicrobial Associated Proteins in Milk

“…In addition to providing nutrients to support the growth of neonates, colostrum, and milk [ 18 , 19 ] are also a source of cellular and non-cellular immune components, antibacterial factors [ 20 , 21 , 22 , 23 ], and other bioactive compounds [ 24 , 25 , 26 ]. These milk components function to promote intestinal health, protect the neonate against infection, modulate immune responses, drive the development of the enteric nervous system, and stimulate the establishment of the gut microbiome [ 18 , 27 , 28 , 29 , 30 , 31 ]. Milk composition can be altered by maternal (gestational and lactational) diets.…”