The Miracle of Producing Milk (from the contents of the intestines and (then) from blood)

“Verily in cattle there is a lesson for you: We give you to drink of what is inside their bellies, from among chyme and from among blood, pure milk palatable to those who drink it” (Quran 16:66)


Human beings have long realized the relationship between the milk secreted and the food eaten by the animal and noticed that the animal would die if it were not provided with food. But they did not know the process of changing the food into milk, flesh, bone, or any other substance.

Modern science has shown us the steps that lead to the formation of milk that is palatable to the drinkers, thus revealing such Signs of Allah, the Most Kind, All-Aware of everything, as agree with what the Qur’an has told us concerning the synthesis of milk in the bellies of cattle, and showing the great Grace of the Creator on His slaves.


Historical Chronology of Scientific Discoveries:

Man could not know how milk is synthesized in the bellies of cattle except after he discovered the mysteries of the digestive system and learned the functions of its organs, and after the discovery of the blood circulation and its connection to the absorption of the nutrients from the intestines and their entrance into the blood. It took a long period of time extending for around five centuries to develop the required instruments and to discover the secrets.

A.  The development of the instruments and devices of research:

Experimental science has followed precise methods to find out the functions of the organs of the digestive system after the invention of the instruments by which experiments and researches were carried out to arrive at precise conclusions. This was not realized but recently. Biologists and physicians in the 14th and 15th centuries were unable to translate their scientific observations into drawings and pictures, and they were less able to distribute them among the students because of the unavailability of the means of publication.

Progress in the scientific instruments used in discovering the mysteries of the process of digestion went on in successive steps till lots of the secrets of digestion were revealed to the researchers.

B.  The history of learning the functions of the organs of the digestive system:

Scientific discoveries concerning the functions of the organs of the digestive system continued from 1833 till the twentieth century, when the successive steps of the digestive process could be illustrated, such as the degradation of the proteins by the gastrointestinal enzyme chains. The structure and effect of the most important digestive juices were shown also, besides confirming the existence of a lot of enzymes that play a key role in the process of digesting the food, such as lactase, lipase and protease, etc. In addition, the effect of the various enzymes functioning in the different stages of the digestive process was discovered.

In 1902 AD Bayliss and Starling together discovered the hormone of secretin. In 1911 AD W. V. Canon illustrated the mechanic factors involved in the process of digestion. In 1913 AD R. Glinard presented a study showing the movement of the intestines recorded on a film.

C.  The history of the blood circulation:

Ibn al-Nafis discovered the lesser blood circulation. Prior to that it had been said that blood was purified in the cavity of the heart. Andrea Alpago translated the work of Ibn al-Nafis at the beginning of the sixteenth century into Latin and the translation was published in Venice in 1547 AD. Thereafter we had Harvey’s researches on blood circulation and they were among the most remarkable researches before the 19th century.

In 1877 AD Laude Bernard proved that the amount of glucose in the blood was constant and that any disturbance in it would cause diabetes. He corrected the concept of Lavoisier and Laplace that the lungs were the center of combustion by saying that combustion takes place in the various tissues.

Marey (1830-1904) improved the technologies of studying the work of the heart and the lungs. His investigations covered the blood circulation (1863, 1881) and the physiology of movement or motion.

In the field of  the physiology of blood circulation since the 19th century several things have been studied, such as the nerves that modify and accelerate the heart, the vascular movement, and other phenomena that are involved in the arterial pressure. These things were investigated extensively during the 20th century.

After using radioactive isotopes the exchanges that take place at the capillaries were better understood.

Thus the way milk is synthesized from the food eaten by cattle was discovered after man had discovered the secrets of digestion and its stages, the functions of the organs of the digestive system, blood circulation, the function of the heart and blood vessels and their routes throughout the body and their relationships with the digestive system and all other parts of the body including the udders and mammary glands of cattle.

The Stages of Forming Pure Palatable Milk

Milk in cattle is synthesized through precise coordination between the digestive system, circulatory system and the reproductive system through the mammary glands in the udders and other organs, in exact calculated steps, for Allah (SWT) assigned to every organ a function and specific duties to do so that we finally have pure milk palatable to those drinking it. The steps of synthesizing milk can be summed up as follows:

Cow digestive system


1.     Digestion:

Digestion is of various types: mechanical digestion, chemical digestion and microbial digestion by means of the enzymes of the microbes in the rumen of the animal. The process of digestion starts in the mouth where the fodder is mechanically broken down into pieces and mixed with the saliva that contains the enzyme (amylase) that achieves the initial digestion that is followed by mechanical, microbial and chemical digestion in the compound stomach.

Then the mass of food is returned to the mouth to be chewed once more and mixed with saliva in the process of rumination. It is then swallowed again and acted upon by the bacteria of he rumen where the carbohydrates and proteins are degraded. This is followed by the enzymatic digestion in the true stomach by means of such enzymes as the pepsin and rennin.

The processes of digestion lead to the change of the food into chyme. When the chyme moves into the small intestine it is exposed to the digestive enzymes in the intestines, pancreas and the bile gland in the liver. Thus the nutrients are degraded from very complex particles into simple particles; starch and complex carbohydrates are converted into simple saccharides; lipids are converted into fatty acids; proteins into amino acids and peptides. As to vitamins, minerals and water, they need no digestion before being absorbed. The solid chyme, after being digested in the intestines, is converted into soft substance.

2.   The extraction from chyme:

The villi in the small intestines absorb the degraded nutrients by various means. These nutrients then reach the capillaries that lie under the epithelial tissue and from there they enter the larger vessels and get involved in the blood circulation.

3.   The extraction from blood:

Then blood carries these nutrients to the various parts of the body including the cells of udders where the components of milk are extracted from blood.

4.   The synthesis of milk in the udder:

The udder is compared to an industrial compound. It is organized into lobes, with each lobe made up of many lobules. Each lobule contains 150-220 microscopic alveoli. Alveoli are sack-like structures where milk is synthesized and secreted. An alveolus is the discrete milk- producing unit consisting of a lumen for collecting milk lined by a single layer of epithelial cells.

Allah (SWT) has made each cell in this industrial unit an integrated self-contained unit that changes the raw materials inside it that come from blood into a droplet of milk secreted into the lumen. These precursors leave the blood and enter the extra-cellular fluid between the capillaries and the epithelial cells. The precursors are then taken up from the extra-cellular fluid through the basolateral membrane of the epithelial cell. Once inside the cell the precursors enter the appropriate synthetic pathway. In addition, some preformed proteins, such as immunoglobulins, are transported intact through the cell. There are five routes by which milk precursors or components enter to produce milk in the alveolar lumen, including uptake of amino acids, uptake of sugars and salts, update of milk fat precursors, uptake of preformed proteins, immunoglobulins and the paracellular pathway.

The Udder

Let us now follow the track of each precursor of milk and what happens to it during its journey across the mammary cell:

1. Amino acids:

Amino acids are absorbed through the basal membrane of the cell. Amino acids are convalently bound together to form proteins at the polysomes (poly–ribosomes) on the rough endoplasmic reticulum (RER). Newly synthesized proteins are transferred from the RER to Golgi apparatus, where they are processed for transport out of the cell through the secretory vesciles that bud from Golgi. At the apical membrane of the cell the secretory vesicle fuses with the inner surface of the apical membrane, which produces an opening through which the vesicle releases its protein contents into the lumen of the alveolus. Thus the protein components of milk are available now.



Alveolar Cell from lactating mammary gland. N, nucleus; TJ, tight junction; GJ, gap junction; D, desmosome; SV, secretory vesicle; FDA, fat-depleted adipocyte; PC, Plasma Cell; BM, basement membrane; ME, cross section through process of myoepithelial cell; RER, rough endoplasmic reticulum. See text for explanation of secretory pathways I (exocytosis), II (lipid), III (apical transport), IV (transcytosis) and V (paracellular pathway).


2. Lactose:

Next we see how another component of the milk. It is the lactose that, with the permission of Allah (SWT) makes milk paalatable to those who drink it. The Glucose that is carried by the blood enters the cell via the basolateral membrane. Some of it is converted to galactose. Both glucose and galactose enter the Golgi apparatus and enter into a reaction resulting in the formation of lactose. The formation of lactose in the Golgi results in drawing water into the cell and into the Golgi; and ultimately becoming part of milk. Thus lactose and water are added to the proteins, waiting for other important milk components, such as lipids.

3. Lipids

The precursors of milk fat synthesis are also  taken up by the epithelial cells at the basolateral membrane. Acetate and B-hydroxybutyrate are important precursors of fatty acid synthesis in mammary cells in some species (ruminants, especially). These precursors along with preformed fatty acids, glycerol, and monoacyl glycerides are absorbed at the basolaterl membrane, to be used for the synthesis of milk fat triglycerides on the smooth endoplasmic reticulum (SER) in small droplets. Numerous small lipid droplets will fuse together as the growing lipid droplet moves towards the apical membrane. At the apical membrane Allah (SWT) directs the large lipid droplet to force  out the apical membrane of the cell and follow the previous milk components that have stored in the lumen of the alveoli. Note that inside the cell, the lipid is not membrane bound and is called a lipid droplet, while after secretion in the lumen, the milk lipid droplets are surrounded by a membrane and called lipid globules.

4. Immunoglobulins:

Milk still requires other components, such as immunoglobulins. They pass across the epithelial cell barrier essentially unchanged from their form in the blood. They bind to specific receptors on the basolateral surface of the cells, are taken “into” the cell in endocytic (transport) vesicles and transported to the apical side of the cell via those vesicles, where the membrane of the transport vesicles fuses with the inner surface of the apical membrane of the cell and releases the immunoglobulins into the lumen of the alveolus. As the transport vesicles traverse the cell they do not seem to interact with the Golgi, secretory vesicles or lipid droplets.

5. Other components:

Water, leukocytes, some ions and minerals take their way to the lumen through tight junctions between epithelial cells.

Thus the journey ordained by Allah for the components of milk comes to an end. No human being whatever his knowledge or technologies can imitate a single mammary cell that produces milk. But Allah, the All-Knowing , All-Powerfull, has made the mammary cell, which cannot be seen except through a microscope, a complete industrial compund to produce milk nonstop in living oragansims that Allah (SWT) cause to reproduce prgeny that need milk. Allah (SWT) sets aside a large part of that milk for human beings and  reminds them of His Grace on them in His Saying:

“Verily in cattle there is a lesson for you: We give you to drink of what is inside their bellies, from among chyme and from among blood, pure milk palatable to those who drink it” (Quran 16:66)

Milk composition


The Interpretation of the Verse

The linguistic meaning:

Al-Farth (chyme) is what is in the rumen.

It is said that it is al-Sarjin (dung) as long as it is still is the rumen.

The Sayings of Commentators:

Commentators differed as to the meaning of the noble Verse because they differed in understanding the indications of some of the words. Some of them thought that the utterance “min baina” (literally: from between) meant “from some” of the chyme and “from some” of the blood, while some others thought that it implied the place, i.e., from a position between blood and chyme. Following is a summary of what the commentators (may Allah bestow His Mercy on them) said:

1.     In a weak hadith attributed to Ibn ‘Abbas (may Allah be pleased with him) we read: “An animal eats the fodder and when it is settled in its rumen it grinds it, in which case it is separated into chyme at the bottom, milk in the middle and blood at the top.” This hadith was narrated by a number of commentators, such as al-Baidawi, al-Qurtubi, Abu al-Su’ud, al-Shawkani, Ibn al-Jawzi in Zad al-Masir, al-Alusi in Ruh al-Ma’ani and others. Some of these commentators commented on the statement attributed to Ibn ‘Abbas (may Allah be pleased with them both) after they noticed that it contradicted observed reality. Abu al-Su’ud, al-Baidawi and al-Alusi said: “Milk and blood are not formed in the rumen.” In Ruh al-Ma’ani, al-Alusi says: “Al-Razi commented on that, i.e., Ibn ‘Abbas’ statement, saying: ‘One may say that milk and blood are not formed in the rumen, which is verified through observation, for animals are frequently slaughtered and nothing of that sort is seen in their stomachs. If what is mentioned in it were produced it would be seen occasionally. What is proved wrong through observation is invalid and should not be depended on.’”

2.     Some commentators say that chyme is the source of both blood and milk; namely, blood comes out of chyme and milk comes out of chyme, too. This is said by al-Baidawi when he interpreted the statement attributed to Ibn ‘Abbas by saying: “If the hadith should be  authentic, it must mean that its middle will be the precursors of milk and its upper part will be the precursors of blood because neither of them is formed in the rumen.” Al-Shawkani said the same in Fath al-Qadir.

3.     Many commentators mentioned what agreed with the findings of modern science that state that the components of milk are extracted from chyme and then from blood. Among those who carried this opinion were al-Qurtubi, Abu al-Su’ud and the author of Ma’ani al-Qur’an, and in Zad al-Masir by Ibn al-Jawzi, where we read: “Chyme is what is in the rumen, which means that milk has been food. From the food blood has been extracted and chyme has been left behind, and from the blood there has been extracted ‘pure milk, palatable to those who drink it.’”

So, we notice the difference among the commentators concerning this issue because of lack of scientific knowledge at their times. Yet, Allah (SWT) guided them to correctly understand the utterance “from between” as meaning “from part of the chyme and then from part of the blood” although they did not know the way that people did not discover except several centuries after the revelation of this noble Verse.

4.     The word “Khalisan” (pure, not mixed with other things) in the Verse is another clue that the components of milk are extracted from blood after it has been extracted from chyme. Al-Tabari hints to this meaning by saying that it (milk) is prevented from mixing with blood and chyme and so they do not mix with it.

But the commentators (may Allah bestow His Mercy on them) did not refer to this explicit meaning but they only said that “Khalisan” (pure, not mixed with other things) implied that “milk did not carry the color of blood or the smell of chyme,” as al-Baidawi and al-Baghawi said, or “the redness of blood or the dirt of chyme,” as al-Qurtubi and al-Shawkani said, or “free from the impurities that characterize blood and chyme,” as Abu al-Su’ud and the Co-authors of Tafsir al-Jalalain said.

The Aspect of the Miracle:

Prior to the invention of the instruments of anatomy in the last two centuries nobody knew the mysteries of what was going on in the digestive system in humans and animals and the functions of this complicated system and its relationship with blood circulation and the stages of milk synthesis in the bellies of cattle.

After the manufacture of instruments and scientific experiments became mature and advanced throughout the centuries, man came to learn that the components of milk are extracted from chyme after the digestion of the food, and run in the blood stream to reach the mammary glands in the udders of females that extract the components of milk from blood retaining no traces of chyme or blood in the milk. In addition lactose is added to the milk in the alveolar lumens to make it palatable to those who drink it.

These secrets were unknown to human beings and they did not discover them except after a long journey of scientific experiments and researches that took centuries and in which there were used unprecedented instruments that were manufactured for the first time by the researchers. But the Holy Qur’an disclosed these secrets to its readers in the most beautiful and most concise utterance 14 hundred years ago. Who then taught Muhammad (peace be upon him), apart from all humans living at that time, the secrets of the digestive system and the circulatory system and the subtle processes going on in the mammary glands other than Allah, Who knows the secrets in earth and heavens and Who knows the mysteries of what He has created? This is enough evidence that the Qur’an is revealed carrying the Knowledge of Allah (SWT) and that Muhammad (peace be upon him) is His Messenger. Allah (SWT) says:

“But Allah bears witness that what He has sent to you He has sent from his (own) knowledge, and the angels bear witness: but Allah is enough for witness.” (Quran 4:166)

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