Daily rhythmicity in nutrient content of asinine milk

Asinine (donkey) milk has been proposed as an alternative to bovine (cow) milk for consumption by human infants who are allergic to bovine milk proteins. To expand the current knowledge of asinine lactation, we investigated daily rhythmicity in the concentration of major constituents of asinine milk. We observed no daily rhythmicity in somatic cell count and pH but observed robust rhythmicity in lipid, lactose, and protein content (robustness greater than 70%, p < 0.01). Lipid and lactose content peaked during the night, whereas protein content peaked during the day. Lipid content of asinine milk was lower than that of human milk, and asinine milk resembled human milk better than bovine milk regarding sugar and protein content.