Sheep’s milk is a food which may result in allergy symptoms in sensitised individuals.

Sheep’s Milk Allergy Test: Allergen Exposure

Sheep’s milk (or ewes’ milk) is the milk of domestic sheep, which has been consumed by humans for thousands of years. It has a sweet and soft flavor and aroma and a creamy texture due to the presence of the small fat globules dispersed in the milk. This also makes it more easily digestible.

Dairy sheep produce around 400-1100 lbs of milk per year, and can only be milked during the period after lambing, which lasts around 90 days. However, using progesterone treatments, ewes can be bred at different times throughout the year, providing farmers with a continuous year-round supply of milk.

Sheep bred primarily for their meat or wool do not produce as much milk as dairy breeds, but may produce enough for small amounts of cheese and other products.

Sheep’s milk is most commonly used to produce cultured dairy products, particularly cheeses. Popular sheep’s milk cheeses include the French Roquefort, the Italian ricotta, the Spanish manchego and the Greek feta.

The milk has a high nutritional value and high concentrations of proteins, fats, minerals, and vitamins, when compared to the milks of other domestic species such as buffalo, cow, goat, pig, camel, mare, donkey, reindeer, and yak. It is also a rich source of various minerals including calcium, phosphorus, magnesium, zinc, manganese, and copper.

Sheep’s milk, like goat milk, has high concentrations of fat globules, which are smaller than those found in cow’s milk, removing the need for homogenization.

Sheep’s milk may sometimes be included in infant formulas such as liquid or powdered milk or baby food.

Sheep’s Milk Allergy Test: Allergen Description

Casein is a heat-stable allergen present in sheep’s milk. The milk also contains various whey proteins which may also result in allergy symptoms in sensitised individuals.

Sheep milk is richer in casein and whey proteins than the milks of other domestic animals.

Sheep’s Milk Allergy Test: Potential Cross-Reactivity

Cross-reactivity between sheep’s milk and cow’s milk and whey might be expected.

In some cases homologous milk proteins of different species can lead to cross‐reactivity in sensitized/allergic individuals.

Studies have shown that some children allergic to cow’s milk protein can experience allergic reactions after ingesting other domestic animals milk, such as buffalo, goat, sheep, donkey, and horse milk.

Sheep’s Milk Allergy Test: Clinical Experience

Sheep’s milk is sometimes recommended as a substitute for cow’s milk in atopic children. However, in one study 15 out of 16 cow’s milk allergic patients also had IgE antibodies against sheep’s milk.

Milking sheep or working in sheep dairies can cause IgE mediated respiratory problems in milk allergic individuals

Other reactions

The lactose content in sheep milk is about the same as that in cow’s milk, and it should therefore be avoided by those who are lactose intolerant.

Consumption of raw sheep’s milk presents a risk due to the potential presence of undesirable food spoilage or pathogenic bacteria.