New Zealand sheep milk: mineral composition

Minerals are key to the maintenance of human metabolism. They interact with proteins providing essential functions, such as iron (Fe) in haemoglobin involved in oxygen transport, and calcium (Ca) and phosphorus (P) involved in bone strength. Nutritionally-essential macro elements include Ca, P, sodium (Na) and magnesium (Mg), while trace elements include Fe, copper (Cu), selenium (Se) and zinc (Zn). All mineral elements are derived from food, and a person’s dietary intake must be adequate to support the physiological functions of everyday health. Sheep milk is a good source of Ca, P, Mg, Fe, Cu and Zn. Concentrations are generally higher than in other ruminant milks, particularly cow milk. Internationally reported concentrations for those minerals range from 136-217, 80-159, 8-19, 0.04-0.10, 0.01-0.09 and 0.38-0.77 mg/100 mL, respectively. The ranges are wider than those found in data for most other domesticated animals. A number of factors alter sheep milk mineral concentrations including animal breed, diet and lactation period. All these factors have larger effects on sheep milk composition than they do on cow milk composition. The mineral content of New Zealand sheep milk has only recently been analysed as part of the 6-year research programme Boosting Exports of the Emerging NZ Dairy Sheep Industry funded by the Ministry of Business, Innovation and Employment (MBIE).