Proteomics characterization of mule milk throughout lactation

Cow milk is a widespread food, but several children are allergic to it – chiefly because of adverse reactions to its proteins. Nutritionally valid, hypoallergenic surrogates are highly sought after, and among them donkey milk is prized for its tolerability and human-like composition. Still, donkeys produce very little milk, with disastrous consequences for marketability and supply chain. Mules are crosses between a donkey stallion and a horse mare, and female ones can be set pregnant via embryo transfer for later lactation, conceivably within economically sustainable production strategies. Owing to their bigger average body size, mules should produce more milk than donkeys, yet the protein profile and allergenicity of mule milk are vastly unknown. Here we present a proteomics characterization of mule milk, obtained following a mule-in-mule surrogate gestation. In addition, preliminary experiments on blood sera from children allergic to cow milk may provide a first hint that mule milk is less allergenic than its cattle analog.