New Insights into Chemical and Mineral Composition of Donkey Milk throughout Nine Months of Lactation

Abstract

Donkey milk is increasingly being proposed as a natural alternative milk for various categories of consumers, especially infants and the elderly population. However, its potential production, gross, and mineral composition have not been deeply investigated yet. Sixty-two individual milk samples were collected monthly from nine Ragusano donkeys reared in a specialized dairy farm. Milk yield as well as chemical and mineral composition, including macro and micro elements, were investigated over an entire lactation, from the second to the ninth month of milking. Milk yield averaged 1.64 kg/day, which highlights good aptitude of the Ragusano breed for the production of milk. Gross composition was characterized by low content of dry matter (8.19%), a high amount of lactose (6.07%), low protein (1.34%), and very low-fat content (0.16%). Whey proteins represented 58% of the total protein, and proteose-peptones accounted for 0.35 ± 0.07 g per 100 g. Total ash content was 0.36 g per 100 g and represented 4.40% of the dry matter. The most abundant element was K, which was followed by Ca, Na, and P. As expected, the micro elements Fe, Zn, and Cu were found in low amounts or in traces. Dry matter, fat, whey proteins. The total ash, Ca, P, Mg, and mineral ratios were significantly affected by the lactation stage.

Equine Milk Production and Valorization of Marginal Areas—A Review

“…The ash content of equine milk (Table 1), which is intermediate between human and cow milk, shows a decline throughout the lactation consistent with Ca and P concentrations in milk [15,20]. Although the absolute values of Ca and P in equine milk are reported variable, and in average higher than in human milk, the Ca:P ratio is reported to be in average 1.3 and 1.72, respectively, for donkey and horse milk, while it accounts for 1.7 and 1.23 in human and bovine milk, respectively [31][32][33]. As a further dietary consideration, the mineral content of milk is not reported to be influenced by the maternal diet in mammalians, except for Se and I [34,35].…”

“…In regards to the mammary gland health status, the somatic cell count is reported to be below 50,000 cells mL −1 milk and mastitis is rarely observed in the dairy equine farm [29,87,89]. However, injuries or improper milking procedures reported for more intensive farming systems can affect the mammary health status [31,87].…”

“…Because the mentioned lack of information in the specific literature on protein and energy requirements of lactating donkeys [20,72,79,98], the common strategy is represented by ad libitum administration of forage-based diets associated to a monthly evaluation of the body condition score [31,79].…”

“…Results of a survey carried out on 12 dairy donkey farms in Italy confirm the inclusion of pasture in the lactating donkey diets always associated to hay administration [72], likely due to the limited availability of pasture. Cereals and/or mixed feeds, commercial or not, are also administered to lactating donkeys, and diets are frequently salt supplemented [31,72].…”

Quantification of Cheese Yield Reduction in Manufacturing Parmigiano Reggiano from Milk with Non-Compliant Somatic Cells Count

“…The content of phosphorus was measured on V-milk and C-whey by colorimetric method [19] and those of calcium and magnesium by atomic absorption spectrometry (AAS Perkin-Elmer 1100 B, Waltham, MA, USA), as reported by Malacarne et al [19]; chloride were determined on V-milk by argentometric Volhard method [20].…”