Colostrum

COLOSTRUM, the secretion of the mammary glands, excreted during pregnancy and in the initial period after childbirth. Usually from the second half of pregnancy, drops of a turbid, watery fluid can be expressed from the mammary glands, which in its morphological and chemical composition resembles the milk of the first days and is by some authors (Dogel) designated as colostrum before childbirth. This secretion of the mammary glands, serving as a manifestation of the preparatory phase for lactation, has no practical significance. Special attention from researchers in recent years has been focused on the study of colostrum after childbirth from the point of view of its value as a nutritional material for the newborn. The period of time when the secretion of the mammary glands has the character of colostrum varies depending on the course of lactation. In primiparas this period lasts longer - up to 2 or more weeks, in multiparas - up to 3-7 days. Skillful use of lactation (properly established feeding, strong sucklers) favors a more rapid transition of colostrum to milk, irregularities in feeding - to delay. The transition of colostrum to milk occurs gradually. Some authors (Jaschke) divide this transition into separate phases: colostrum, early, medium, and mature milk. Colostrum differs from milk primarily in its external appearance. It is secreted in the form of thick drops of intense or pale yellow color. The color depends on the coloring matter associated with the fat of colostrum and absent in the fat of milk. Colostrum is thicker than milk, has great tensile strength and stickiness. It curdles when boiled. Specific gravity - 1.050-1.060. Viscosity reaches 4.433. Freezing point depression - 0.549-0.595. Phenolphthalein reaction (acidic) is half as weak, litmus reaction (alkaline) is twice as strong as in mature milk. Its Morphological composition. A essential feature of colostrum is the presence in it, in addition to milk globules, a large number of various cellular elements, which by some authors are designated by the general name - colostral bodies. Other authors distinguish among these cellular formations 1) proper colostral bodies (corpuscula colostrum), first discovered by Donne (1837) and representing large (13-40 μ, 4-5 times larger than milk globules) round, sometimes irregularly shaped cells with pale-staining nuclei and numerous small fat inclusions; 2) leukocytes - of smaller size than colostral bodies (12-14 μ), mononuclear and polynuclear with pale-staining nuclei and fat inclusions and 3) "capped cells", first discovered by Heidenhain and representing milk globules of oval or ellipsoidal shape, covered on one of the poles with a granular substance in the form of a cap; these caps are particularly sharply pronounced under the action of osmic acid, which colors the fat black and the granular caps yellow. The solution of the question of the origin of all these cellular formations (as well as milk globules) is closely connected with the solution of the question of the essence of the secretory function of the mammary gland. If epithelial cells of the mammary gland play an exceptional role in the formation of the formed elements of milk, then all these cellular formations of colostrum represent epithelial cells that have detached from the glandular parenchyma and undergone fatty degeneration (Popper). According to other authors, milk globules represent leukocytes that have penetrated from the lymphatic vessels and stroma of the gland into the walls of its milk ducts. Under the influence of a special enzyme produced by the metabolic activity of the epithelium, leukocytes undergo changes, first turning into colostral bodies, and then after the breakdown of colostral bodies - into milk globules. And finally there is the assumption that the main mass of colostral bodies is of leukocytic origin, but along with them there are also epithelial cells that have undergone fatty degeneration (Arnold). In any case, it is undoubted that the role of non-epithelial elements (lymphocytes and leukocytes) in the origin of colostral bodies is significant. In women who do not nurse or have stopped nursing, colostral bodies are found predominantly in the secretion of the mammary glands. The study of the morphological composition of colostrum has led some authors to attempt to predict milk production based on the morphological picture of colostrum. The presence of more than 70% polynuclear leukocytes allegedly indicated high milk production, the predominance of lymphocytes - on weak lactation. Later observations (Jaschke) did not confirm this. In chemical composition, colostrum differs sharply from milk; at the same time, like its morphological composition, it gradually transitions into the chemical composition of mature milk. The following excerpts from the tables of Camerer and Soldner illustrate the sharp difference in chemical composition between colostrum and milk and the gradualness of the transition. Time after childbirth In 100 g there is contained in colostrum and milk (in grams) nitrogen fat milk sugar ash protein 26-51 hours . 5-6 days . . After 10 weeks .... 0.928 0.327 0.141 4.08 2.89 3.36 4.09 5.75 7.28 0.48 0.34 0.18 5.80 2.04 0.88 As can be seen from the table, colostrum differs from milk primarily in its high content of nitrogen (protein) and mineral salts, which is explained by the richness of colostrum in cellular elements. The amount of sugar is slightly more than half that in mature milk. This is explained by the fact that in the colostral period, along with secretion, there is also resorption, which contributes to the reverse absorption of milk sugar (lactosuria at the beginning and cessation of lactation in nursing women). The amount of fat in colostrum approaches that in milk. The composition of ash is currently established by the research of Schloss and Birk as follows: Components Total amount of ash CaO........... K2O........... Na2O.......... P2O5.......... MgO .......... In 100 g of colostrum, according to Schloss and Birk 0.2814 0.0360 0.077 0.0544 0.017 0.0093 0.3048 0.0335 0.0795 0.0532 0.0621 0.0069 In 100 g of mature milk, according to Schloss 0.1839 0.0375 0.0529 0.0188 0.0404 0.0085 Attention is drawn to the fact that along with the large content of the total amount of salts, there is a large content of P2O5 and Na2O in the ash of colostrum; this fully corresponds to the needs of the newborn organism; the content of cholesterol and lecithin is also usually higher in colostrum than in milk. - Nutritional value (caloric content) of colostrum in the first days significantly exceeds that of milk, but gradually decreases with each day. A number of recent studies (Gans, Langstein, Rott, Edelstein) gave the following average figures for the caloric content of colostrum: 1st day - 1500 calories per 1 liter; 2nd day - 1100; 3rd day - 800; 4th day - 750; 5th day - 700; 6th day - 675; 7th day - 600. Thus, colostrum is compared to mature milk a more concentrated food; in a small volume it contains a large amount of nutritional material. Biological properties of colostrum. Research by a number of authors has undoubtedly established that the secretion of the mammary gland cannot be considered only as a nutritional fluid, but possesses biological properties inherent in living tissue. Recent research particularly emphasizes these properties in relation to colostrum. Thus, Bauereisen and Graetz proved that the proteins of colostrum are in very close relationship with the serum albumin of the mother. Colostrum and maternal blood serum contain almost the same amount of protein (8.15-8.41%), while serum from umbilical cord blood has only 5.5%, and milk only 1%. Jaschke and Lindig in 1915 by the Abderhalden method proved that the albumins and globulins of colostrum, in contrast to milk protein, cannot be considered foreign, and therefore can freely pass through the intestine of the newborn. Ehrlich and subsequently Jaschke succeeded in establishing the transmission of immune bodies, antitoxins and agglutinins from mother to newborn during the colostral period, which is explained by the large content of cellular elements in colostrum. According to Kleinschmidt, colostrum contains specific hemolysins. By experiments of Bauer with deviation of complements, it has been proved that in colostrum there are antigens that are found in blood serum. - Thus, a comprehensive study of colostrum gives the right to express the assumption that feeding the newborn with colostrum represents a gentle transition from intrauterine (parenteral) to extrauterine (enteral) feeding. The value of such a gradual, gentle adaptation of the nutritional material to the intestine of the newborn consists not only in that the weak digestive tract of the newborn with weak enzymatic ability is not immediately presented with impossible demands, but along with this, due to the biological properties of colostrum, the protection of the newborn organism from the harmful influence of the bacterial flora, gradually populating its intestine from the first day of life, is achieved.

According to Schloss and Birk 0.2814 0.0360 0.077 0.0544 0.017 0.0093 0.3048 0.0335 0.0795 0.0532 0.0621 0.0069 In 100 g of mature milk, according to Schloss 0.1839 0.0375 0.0529 0.0188 0.0404 0.0085 Attention is drawn to the fact that along with the large content of the total amount of salts, there is a large content of P2O5 and Na2O in the ash of colostrum; this fully corresponds to the needs of the newborn organism; the content of cholesterol and lecithin is also usually higher in colostrum than in milk. - Nutritional value (caloric content) of colostrum in the first days significantly exceeds that of milk, but gradually decreases with each day. A number of recent studies (Gans, Langstein, Rott, Edelstein) gave the following average figures for the caloric content of colostrum: 1st day - 1500 calories per 1 liter; 2nd day - 1100; 3rd day - 800; 4th day - 750; 5th day - 700; 6th day - 675; 7th day - 600. Thus, colostrum is compared to mature milk a more concentrated food; in a small volume it contains a large amount of nutritional material. Biological properties of colostrum. Research by a number of authors has undoubtedly established that the secretion of the mammary gland cannot be considered only as a nutritional fluid, but possesses biological properties inherent in living tissue. Recent research particularly emphasizes these properties in relation to colostrum. Thus, Bauereisen and Graetz proved that the proteins of colostrum are in very close relationship with the serum albumin of the mother. Colostrum and maternal blood serum contain almost the same amount of protein (8.15-8.41%), while serum from umbilical cord blood has only 5.5%, and milk only 1%. Jaschke and Lindig in 1915 by the Abderhalden method proved that the albumins and globulins of colostrum, in contrast to milk protein, cannot be considered foreign, and therefore can freely pass through the intestine of the newborn. Ehrlich and subsequently Jaschke succeeded in establishing the transmission of immune bodies, antitoxins and agglutinins from mother to newborn during the colostral period, which is explained by the large content of cellular elements in colostrum. According to Kleinschmidt, colostrum contains specific hemolysins. By experiments of Bauer with deviation of complements, it has been proved that in colostrum there are antigens that are found in blood serum. - Thus, a comprehensive study of colostrum gives the right to express the assumption that feeding the newborn with colostrum represents a gentle transition from intrauterine (parenteral) to extrauterine (enteral) feeding. The value of such a gradual, gentle adaptation of the nutritional material to the intestine of the newborn consists not only in that the weak digestive tract of the newborn with weak enzymatic ability is not immediately presented with impossible demands, but along with this, due to the biological properties of colostrum, the protection of the newborn organism from the harmful influence of the bacterial flora, gradually populating its intestine from the first day of life, is achieved.