Colostrogenesis: The Formation of Bovine Colostrum
Colostrum is formed in a pregnant cow about 3-4 weeks before calf delivery. Fluid containing growth factors and other substances are released into the mammary tissue that is currently being developed. Hormones, such as progesterone, regulate this process. The hormones attach to cell receptors which line the mammary gland and prevent the glands from secreting any fluid throughout the pregnancy. About 2 weeks before calf delivery, these hormones assist in the appearance of specific cell receptors which line the mammary gland. These receptors help transfer substances from the pregnant cow's blood into the mammary gland. Some of these substances are necessary antibodies, growth promoters and growth hormones which help in the development of the baby calf.
The hormone balance in the mother cow begins to change about 2 days prior to the birth of the calf. This hormone change initiates secretions and combines substances together. After the baby calf is born and the placenta is delivered, progesterone levels in the mother drop. The blocking of secretions by progesterone is eliminated; a protein-based substance is created in the mammary gland cells and transfers of substances from the mother's blood into the mammary gland are stopped. The fluid in the mother cow found in the mammary gland at birth is called colostrum. It contains high amounts of hormones, metabolically active substances and growth promoters. Colostrum also has a high concentration of protein, is rich in milk fat and low in its lactose content.
After birth, one of the most influential factors on the composition of subsequent secretions is physical removal of the fluid from the mammary gland. The removal of even small quantities of fluid triggers the production of copious amounts of secretion from the cells in the mammary gland. Since the transfer of biologically-active substances from the mother's blood is blocked, replacement fluid will contain primarily substances synthesized by cells in the mammary gland and, thus, will be of a different composition than the fluid originally contained in the mammary gland at birth. The fluid expressed at this time is known as transitional milk. This is further complicated by the fact that the basic composition of the colostrum changes after birth due to maternal reabsorption and does so rapidly beginning at six hours, as can be seen from the table below.10 Thus, the highest quality bovine colostrum, containing the maximum concentration of biologically active substances, is collected in a single milking during the first six hours after parturition.
While the colostrum in the mother cow are changing quickly after the birth of the calf, the baby calf is undergoing a number of changes in its body. Within the first six hours of life, the calf's stomach lining does not produce any acid and there are a limited number of enzymes which break down proteins that are ingested.
Therefore, these conditions work in favor of having the biologically active substances in complete colostrum pass through the calf's stomachs into the upper portion of the small intestine without being broken down. During the first 6-8 hours of life, an area in the upper duodenum has specialized sites where the biologically active substances can be absorbed and transported directly into the calf's bloodstream. After this period, the stomach begins to acidify, enzymes appear and the specialized absorption area in the small intestine changes dramatically so that most of the biologically active substances in colostrum are no longer absorbed. This process is aided by the fact that calves are born with a well-developed system of lymphoid tissue under their tongue and at the back of their throat that persists throughout their entire life. Many biologically active substances are absorbed through these tissues when the calf suckles its mother or a nursing bottle. - 17268
The hormone balance in the mother cow begins to change about 2 days prior to the birth of the calf. This hormone change initiates secretions and combines substances together. After the baby calf is born and the placenta is delivered, progesterone levels in the mother drop. The blocking of secretions by progesterone is eliminated; a protein-based substance is created in the mammary gland cells and transfers of substances from the mother's blood into the mammary gland are stopped. The fluid in the mother cow found in the mammary gland at birth is called colostrum. It contains high amounts of hormones, metabolically active substances and growth promoters. Colostrum also has a high concentration of protein, is rich in milk fat and low in its lactose content.
After birth, one of the most influential factors on the composition of subsequent secretions is physical removal of the fluid from the mammary gland. The removal of even small quantities of fluid triggers the production of copious amounts of secretion from the cells in the mammary gland. Since the transfer of biologically-active substances from the mother's blood is blocked, replacement fluid will contain primarily substances synthesized by cells in the mammary gland and, thus, will be of a different composition than the fluid originally contained in the mammary gland at birth. The fluid expressed at this time is known as transitional milk. This is further complicated by the fact that the basic composition of the colostrum changes after birth due to maternal reabsorption and does so rapidly beginning at six hours, as can be seen from the table below.10 Thus, the highest quality bovine colostrum, containing the maximum concentration of biologically active substances, is collected in a single milking during the first six hours after parturition.
While the colostrum in the mother cow are changing quickly after the birth of the calf, the baby calf is undergoing a number of changes in its body. Within the first six hours of life, the calf's stomach lining does not produce any acid and there are a limited number of enzymes which break down proteins that are ingested.
Therefore, these conditions work in favor of having the biologically active substances in complete colostrum pass through the calf's stomachs into the upper portion of the small intestine without being broken down. During the first 6-8 hours of life, an area in the upper duodenum has specialized sites where the biologically active substances can be absorbed and transported directly into the calf's bloodstream. After this period, the stomach begins to acidify, enzymes appear and the specialized absorption area in the small intestine changes dramatically so that most of the biologically active substances in colostrum are no longer absorbed. This process is aided by the fact that calves are born with a well-developed system of lymphoid tissue under their tongue and at the back of their throat that persists throughout their entire life. Many biologically active substances are absorbed through these tissues when the calf suckles its mother or a nursing bottle. - 17268
About the Author:
Dr. Anthony Kleinsmith is an expert in colostrum research. You can learn more about the colostrum benefits by visiting his online resources at ImmuneTree.com today!
posted by X - Men at
1:14 AM
0 Comments:
Post a Comment
Subscribe to Post Comments [Atom]
<< Home