Often we are advised and told not to offer milk to parrots, as they do not digest lactose. It is good and above all… it is true!
But why is that?
Not to offer milk is not a dogma of the parrot bible that you have to believe without understanding or any of these avian legends which have the rind. The best is to take a quick look at it in order to understand the why and how.
The first real reason that falls under the ax of logic is that: parrots are not mammals and that only the latter are fed on mother’s milk during their juvenile period. Parrots, on the other hand, are oviparous (an animal which reproduces by eggs which are laid before hatching ), do not have udders and feed their young by regurgitation of food from the crop.
The term often heard “crop milk” does not refer at all to the milk of mammals, we are talking here about secretions and cells coming from the crop of the parrot parent during the regurgitation of the predigested food.
Milk is a white, opaque, highly nutritious liquid secreted by the mammary glands of female mammals ( Petit Robert ). Milk is therefore the natural food of baby mammals and they have the enzyme essential for its digestion, namely lactase. This enzyme is not produced by the parrot, since it would be completely useless, not being a mammal …
The main nutrient in milk is water in a proportion of 87 to 91%, depending on the level of fat. The other nutrients are lactose at 4.9%, fat at about 3.5% and protein, also at 3.5%. There are also other nutrients which are made up of minerals and vitamins.
Lactose (the sugar in milk ) is usually unique to mammals. Birds cannot make it, cannot digest it or absorb it. This means that when a parrot ingests lactose, it stays intact in its digestive system until it is fermented by bacteria or evacuated in the droppings. When lactose stays in the bird’s intestine at a certain dose, it draws water to that part of the body; the water ferments the lactose, which causes diarrhea in the parrot. The amount of lactose required in a diet to produce diarrhea is 10 and 30% of the dry weight value of the food ( without water ) ingested by the bird.
When products like cheese, butter, yogurt, powdered milk and dried whey are made, the nutrients in the milk are retained, released or processed. For example: in cheese, most of the fat and protein is retained, but lactose, part of the protein as well as water-soluble vitamins and minerals are found in whey, which is the liquid that remains after coagulation of the cheese and, at the end of the process, is separated from the preparation.
In the case of yogurt, the fermentation of lactose produces lactate. Lactose and lactate are very different, despite the similarity of their names. Water, proteins, minerals and vitamins and sometimes milk fat are generally beneficial to the bird ( unless they are found in too high concentrations ). There is little to worry about these nutrients. The main problem with milk is lactose.
Lactose is the natural sugar found in milk. Lactose is actually the biggest problem with milk. The percentages of lactose vary from product to product. For example: skimmed milk powder contains 50% and dried whey is worse, it contains 70%. In cheeses and yogurts, lactose is separated and is found in the whey that is not preserved. In the case of yogurt, the fermentation of lactose turns it into lactate which does not bother parrots.
Lactase tablets ( like Lactaid ) or milk with added lactase for people with lactose intolerance should never be given to a parrot.
Although lactase is the enzyme that is used to absorb lactose, converting it into glucose and galactose ( two smaller forms of sugar ) and mammals convert these forms to sugar without any problem, there is a A major problem in parrots that cannot be found in mammals: birds cannot convert galactose into glucose and, consequently, galactose accumulates in their blood and interferes with the transport and assimilation of glucose. This action often results in the death of the parrot.
Dairy products are not necessary in the diet of your parrots, but if like me you live with “cheese-addicts”, do not offer cheeses made from raw milk. On the other hand, there is no contraindication in the case of yogurts and, what I have found best as a substitute for cow’s or goat’s milk, soy milk. Parrots see nothing but fire and can continue to eat their milk cereals in the morning!