Donkey milk, derived from female donkeys (jennies), is a little-known yet fascinating dairy product with a great history. From ancient Egypt where Cleopatra bathed in it for beautiful skin to the use of the milk as a substitute for breast milk for orphan infants in nineteenth-century Europe, donkey milk has been known for its food and therapeutic value for eons. Now this product is receiving the attention accorded nutraceuticals (foods with medicinal qualities). Especially in areas such as Italy, Serbia and India, donkey milk is being produced in small farms for specialty markets. But a jenny produces only 0.5 to 2 liters a day, instead of the many gallons produced from cows. Thus donkey milk has been a rare and costly product, being sold for the most part in freeze-dried form, as a component in cosmetics and in specialty food products such as chocolates and infant formulas.
What is remarkable about the milk is its similarity to human breast milk, which also contains low fat, high lactose and different protein types with a high content of whey protein, which aids in digestibility and gives rise to less allergenicity. Certainly this milk has great possibilities in the treatment of cows milk allergy (hypersensitivity) and especially for persons suffering from digestive disturbances, etc. The scarcity and high cost of donkey milk as well as special limitations in its application, however, raise niggling questions in regard to its practicability of use.
This nutrition of donkey milk and the newest findings and practical research make this milk interesting, especially in relation to their therapeutic possibilities. This article is published to present to the interested layman and especially to those who are thinking of their physical well-being some of the interesting results of research in connection with this milk, and their astonishing possibilities and very definite opportunities which they offer not only in feeding the infant, but after that in furtherance of health as is evidenced by the psychological changes undergone in psychoanalysis, mental therapeutics, etc.
The food values of donkey milk is of great importance as shown by the investigations which have been made by a number of amateurs and research workers. One hundred mL of milk contains approximately 40 to 50 calories, 1.5 to 2 grams of protein, 6 to 7 grams of carbohydrates (mostly lactose), and 0.3 to 1.8 grams of fat, depending upon the breed of donkey and its diet. When compared with other milks, this is a very light product — cow’s milk contains about 3.5 grams of fat with 60 calories, goat’s milk contains about 4 grams of fat with 69 calories. This finds favor with those who are on low-caloric diets. The high lactose content is an excellent energy food, and at the same time increases the flora of the intestine, giving increased effect to the prebiotic. Although the protein content is small, it is by no means insignificant, being made up of whey proteins lactoferrin and lysozyme, both of which have anti-microbial and immune-stimulating properties. Since the casein content is reduced (about 40% from that of cow’s milk), the probability of sensitiveness to the milk proteins is reduced and the ease of assimilation increased. The amino acids have a profile that resembles those of mother’s milk and give the requisite building blocks for tissue repair and growth. Donkey milk is a treasure house of essential nutrients. The amount of vitamin D present is substantial (up to 20% of the required daily intake per 100 mL). The amounts of lactating substance in stallion milk are greater than that of milk of most other animals from the point of view of supply. Vitamin D is concerned with the growth of bone, and immunity and corresponds more with mother’s milk than other milk will do. The amounts of vitamin A are considerable (for the eyes), and vitamin C is also present (important that the active supplements are obtained). The minerals are of importance, and calcium is present, 60 to 100 mg of calcium per 100 mL of milk, and potassium, heart and skeleton is improved. The fat is small in amount, but it contains unsaturated or healthy fats, such as omega 3 fats (EPA and DHA). These are conducive to brain and heart health. The fat globules are as a rule (1 to 2 microns) in size, which means that the milk is better taken up by the intestine on the fat globules compared with cow’s milk (the fat globules being larger). Though nutritionally inadequate to be the exclusive food for infants and may therefore need the use of synthetic or other substitute food in medical or pediatric employment, its low caloric and protein content, and yet it is a highly nutritious and somewhat light food, which renders it possible to use donkey’s milk as a functional food to fill a place in diets necessitating such use.
Health benefits:
Hypo-allergenic for milk allergies:
The low casein and beta-lactoglobulin content of donkey’s milk places it most prominently in consideration of therapeutic value for sufferers from cow’s milk protein allergy (CMPA), which occurs in 2–3 % of infants, and some adults. Trials have been numerous, but we will confine ourselves in our first report to a very complete one which has just been published from Italy and which deals with 81 children. These had been diagnosed as suffering from CMPA and a considerable number of the most prominent leading authorities were concerned in the work. The donkey’s milk was tolerated by all the children, who also showed normal growth and weight increase without any allergic manifestations. The milk is also of considerable service in improving the digestion in those with sensitive stomachs, such as the patients suffering from irritable bowel or inflammatory conditions of the bowel, since in the various trials it has been shown to produce less gastric disturbance than cow’s milk.
Support of the immune system:
The bio-active products contained in donkey’s milk (notably the lysozyme and lactoferrin) are extremely efficient against micro-organisms producing such diseases as Salmonella and Escherichia coli and Listeria and also some of the viruses. These properties render them very valuable in reducing the incidence of some diseases and also for extending shelf life of the milk to four days cold. The whey proteins present produce a stimulation of the immune cells such as the macrophages and cytokinins resulting in an increase in defense, notably in the old or those whose immunity is weak. Preliminary investigations have also suggested that there is an increase in the production of nitric oxide, helping circulation in the blood and probably also the reduction in blood pressure.
Skin and antiaging benefits:
The use of donkey’s milk for cosmetic purposes is not modern, but the discovery of the beneficial value of donkey’s, or any other milk, has lately received much valuable confirmation from modern experimental science. The proteins contained in the milk hydrate the skin by adhering to the water, and the anti-oxidants, notably vitamin C, contained in the milk, are very useful in combating oxygen free radical damage, notably the damage caused by the ultra violet rays of the sun, and hence also a lessening of age changes in the skin, such as wrinkling. It is reported from many sources that it has a very salutary effect in increasing the elasticity of the skin and generally soothing irritative conditions, and due to these properties it is so greatly in demand as a cosmetic substance, it is used in creams, soaps and serums. The same conclusions hold good in the skin affections also, such as eczema and psoriasis, probably owing to their reducing effect upon inflammation.
Metabolic and Cardiovascular Health:
The high whey protein fraction is likely to be of benefit in the areas of insulin sensitivity/glucose utilization, with beneficial effects in the diabetic population (Type II). The low saturated fat and high omega 3 distribution would be beneficial for cardiovascular health, as they have been found to lower cholesterol and inhibit the formation of arterial plaques. Studies on animals suggest that the ACE-inhibiting peptides contained in donkey’s milk may have a positive influence on blood pressure, and the low calorific density may benefit the obese population.
Pediatric and Geriatric Nutrition:
Donkey’s milk contains a series of oligosaccharides and thus may be an appropriate food for infants that cannot be breast fed. The oligosaccharide content promotes healthy gut flora whereas the galactose content may be beneficial for brain development. The elderly have been shown to benefit from the good digestibility and high nutritional density of donkey’s milk consumption as a food product, especially those with good appetites and impaired digestion. Antitumor and antiproliferative (anticancer) effects have been observed but are still in their infancy with respect to human studies.
Mental Health Potential:
The antianxiety potential of donkey’s milk in tests on animals has been established, having been shown to reduce animals anxious behavior. This may be due to bioactive peptides which have effects akin to mild anxiolitics. Such potential for conditions of a stress-related order may be anticipated based on this observation, but data on the human population remain scant.
Disadvantages and Consideration:
High Costs and Availability:
The low yield of donkey’s milk (1 – 2 liters per day per jenny) and production system being labor intensive manufacture increase costs and make it many times more expensive than cow’s milk. Because the size of the farms of goats is small and the actual production is limited, being mainly in Europe and some Asian parts of the globe, the availability of donkey’s milk is limited. The powdered form is the most common, still very dear and perhaps outside the reach of the bulk of the population sectors. Risks of Contamination
Raw donkey milk (as with any unpasteurized milk) can be a source of pathogenic microorganisms, such as Listeria and Salmonella, and is thereby a risk for neonates, pregnant women, or those who are immune compromised. To mitigate this risk, pasteurization can safely be employed; however, this can render some bioactive constituents less effective.
Lactose Sensitivity:
Horse milk is better tolerated than cow milk, but its significant lactose content (6-7 g/100 mL) can bring about constipation, diarrhea or cramps in lactose intolerant individuals. Persons with a severe degree of lactose intolerance should avoid donkey milk or utilize a lactose free alternative.
Allergic Hypersensitivity:
Although rare, some persons can experience allergic reactions to donkey milk proteins resulting in urticaria, angioedema, and respiratory distress. Persons with a history of milk allergies, should check with their physician before using donkey milk.
Processing Difficulties and Cooking Limitations:
Because of the low content of casein in donkey milk, it is not practically possible to prepare cheese, or yogurt products, using this raw material and therefore limits its functional variations in the culinary arts. Brought to a boil it will sediment, and because it has low creaming ability, it does pose certain cooking difficulties.
Sustainability Issues and Ethical Considerations:
The raising of donkeys to supply milk raises certain issues as it is concerned with sustainability. The yield per animal is so small that in order to maintain an adequate supply, larger herds must be possessed which might be considered a strain upon limited resources. There are also ethical considerations with respect to the management of the jennies and their foals, for in order that they remain a proper source of milk, it is necessary to separate mother from offspring, and this can create stress within the animal population. The limited rules concerned with this activity in certain parts of the country may give rise to further difficulties in this regard.
Nutritional Inadequacies for Infants:
While donkey milk has certain attributes which render it similar to mothers milk, it does not fall into what can be called an adequate source of nutrition for the infant (ultimately without nutritional supplement) due to its low caloric or protein content if used as such. It is a very unsuitable substitute for other milks and at the same time for the use of infants without the use of medical supervision.
Comparison With Other Alternate Milk Substitutes:
As compared with non-animal based milk substitutes such as that derived from nuts or oats, donkey milk acquires a far greater source of high quality protein as well as nutrients that are bioactive, but is more costly and has less sustainability in source. As compared with other animal based products such as goat milk it is lower in fat and protein, and it is as muscles all or less hypoallergenic as goat’s milk, and dromedary milk would possess similar antimicrobial properties and advantages but difficult of source and cost. Donkey milk occupies a specific and special niche for being a milk substitute which is digested by infants and yet would be bioactively and otherwise safe. The supply has also limited availability which may compromise its competitiveness.
Cultural And Market Mobility:
In certain countries, notably Italy, donkey milk has found its own niche in the area of the special needs associated with medical foods considered useful in the production of cosmetics but, nevertheless, products are appearing in Serbia, India and China. Cultural taboos in certain areas, where products derived from donkey milk are considered unconventional, on occasion complicate the availability of such products to consumers. By virtue of its niche the market concerned is small but growing as awareness is therefore developing as to the need and the possibilities connected with the use of donkey milk and the growing knowledge of its assets, particularly in the area of wellness and pediatrics.
Finally, Donkey milk is a milk that is rich in nutrients and in general hypoallergenic, which has significant health advantages out of those nutritional connected with immunity factors (by necessity) towards skin health, metabolic factor and cardiovascular improvements that can take place. Its similarity to human milk is specifically useful in certain target populations but due to limitations caused by cost, limited availability and the dangers either of contamination or lactose intolerance, requires considerable consideration. It is however superior nutritionally than any other found milks and possesses also certain properties which are interesting and bioactive, but at the same time we are faced with various practical or ethical problems. Nevertheless, for those who are interested in alternative solutions for dairy products, donkey milk runs in but is preferably still to be used under sufficient medical supervision for therapeutic means. With the first spark that has come through in the field of research and in the field of production, medical usage should also accrue to considerable volumes and by this each country possibly a larger niche in the world market for health and wellness.