Research on donkey milk · Study 89

Nine months of lactation: milk yield, composition and minerals in Ragusano jennies

A team from the Universities of Parma and Catania followed nine jennies of the Sicilian Ragusano breed from the second to the ninth month of lactation – with monthly milk yield measurements and a detailed analysis of protein, lactose, fat and minerals.

Important: A milk analysis in jennies from one dairy farm. It describes milk yield and composition and does not examine any effect of donkey milk in humans.

Lactation calendar · runs automatically, tappable

Eight stages, one lactation

Milk kg/day
Lactose g/100 g
Crude protein g/100 g
Samples

Fill level = daily milk (least-squares mean) per stage in days of lactation. Milk was recorded between 6 am and 3 pm after the foal was separated from its mother – not the total daily milk.

Course of lactation · choose a measure

How the milk changed over 280 days

Dots = least-squares means, bars = standard error, x-axis = days of lactation (class midpoint). Each axis starts at zero.

Minerals · all 62 samples

Mean and range

Bar = lowest to highest measured value, line = mean, in mg per 100 g of milk. Potassium was the most abundant mineral, followed by calcium, sodium and phosphorus. Calcium, phosphorus and magnesium fell markedly after about 160 to 190 days of lactation.

2.24 mg/kgzinc on average (0.99–4.63)

2.29 mg/kgiron on average (0.57–9.59), highest stage value 4.69 mg/kg at 160–189 days

0.31 mg/kgcopper on average (0.15–1.17), no significant change

Critical assessment

Six labels on this study

Nine jennies

One farm, one breed. In the last two stages only five samples each were available.

Not the whole daily milk

The milk measured was obtained after separation from the foal (6 am to 3 pm). What the foal drank is not included.

Differing figures

The discussion gives an average of 6.4 g lactose and 1.6 g protein per 100 g, whereas Table 1 gives 6.07 and 1.34 g.

Ethics statement

According to the authors, samples were taken during routine veterinary checks. No ethics reference number is given.

Content, not availability

Mineral contents were measured. How much of them is available to the body was not examined.

Careful laboratory work

Reference methods (Kjeldahl, atomic absorption), monthly repetition, funding from the University of Catania, no conflicts of interest.

clear limitationnotestrength

Editorial assessment: The authors describe Ragusano jennies as good milk producers and the milk as nutritionally interesting. We report the measured values and do not adopt any evaluation. For comparison: Study 86 (Amiata jennies) and Study 55 (course of lactation in Romania).

Research question for DON DONKEY’S®

What does the day of lactation reveal about the milk?

In this study, protein, lactose, calcium and phosphorus fell over the course of lactation, while iron rose temporarily. Whether and how we can usefully document the lactation stage of a batch is a question we are following up.

Record lactation stageCompare with Studies 55 and 86Test minerals in the laboratory

Original publication

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

Original title of the publication.

Malacarne M., Criscione A., Franceschi P., Bordonaro S., Formaggioni P., Marletta D., Summer A.
Animals · 2019 · volume 9, issue 12, article 1161 · open access
University of Parma and University of Catania (Italy)

DOI: 10.3390/ani9121161

Transparency: funded by the University of Catania (research plan 2016–2018). The authors declare no conflicts of interest. No product-related statement for DON DONKEY’S®.

Summarised and reviewed by the DON DONKEY’S editorial team on the basis of the original publication · as of October 2026

End of the study summary

Note on our products

The study summarised above was carried out independently of DON DONKEY’S® and does not relate to our products. It serves solely to inform about the state of research.

DON DONKEY’S® donkey milk and donkey milk powder are foods. They are not intended to prevent, treat or cure any disease and do not replace medical advice.

From our shop

DON DONKEY’S® donkey milk

100 % donkey milk · raw milk, frozen

On this page we report the findings of a published study. Independently of that, you will find our donkey milk here: 100 % donkey milk, frozen as raw milk.

Transparency: The study examined milk from Ragusano jennies in Italy – not the milk from our partner farms.

€24,90

100 ml bottle / 100ml · Unit price: €249,00 / 1 l · incl. VAT, plus shipping

View all sizes & purchase options →

Also in our shop

Donkey Milk Powder

Donkey milk in powder form

For anyone who prefers a longer shelf life: our donkey milk in powder form – easy to store and portion.

Transparency: The study examined fresh donkey milk, not our donkey milk powder.