Donkey Milk Study: Polar Lipids in Donkey and Cow Colostrum (Zhang 2025)

In donkey and bovine colostrum, 206 polar lipids from 11 subclasses were identified; 141 differed significantly. Sphingomyelin accounted for 70.7% of the polar lipids in donkey colostrum and 50.9% in bovine colostrum.

The study in brief

• Original title: Lipidomics profile shows differences of polar lipids between donkey and bovine colostrum: a comparative study
• Authors: Zhang Y., Chen J., Liu Z. et al.
• Journal: Food Chemistry: X, 29, 102798 (2025)
• Country: China · Study type: Laboratory study

How it was investigated

Colostrum from 30 Dezhou donkey mares (2–4 years, 0–5 days after birth, shared pasture of one farm near Dalian) was compared with colostrum from 30 Holstein cows (2–4 years, 1–5 days after calving, farm near Shenyang). For each animal species, the 30 samples were randomly grouped into 10 groups of three samples each and analyzed. The lipids were extracted with chloroform/methanol, the polar lipids separated by acetone precipitation and quantified by UHPLC-triple quadrupole mass spectrometry in MRM mode with isotope-labeled internal standards.

Important figures

• 30 + 30 – Colostrum samples from donkey mares and cows, analyzed in 10 groups per animal species
• 206 – Identified polar lipids in 11 subclasses
• 152 (73.79 %) – Of which glycerophospholipids
• 54 (26.21 %) – Of which sphingolipids
• 70 (33.98 %) – Phosphatidylethanolamine – most abundant subclass
• 70.7 % vs. 50.9 % – Proportion of sphingomyelin in polar lipids, donkey vs. bovine colostrum

Results

In donkey and bovine colostrum combined, 206 polar lipids from 11 subclasses were identified: 152 glycerophospholipids (73.79 %) and 54 sphingolipids (26.21 %). By number, phosphatidylethanolamines (70), phosphatidylcholines (33) and sphingomyelins (22) dominated.

In terms of quantity, sphingomyelin was the largest subclass in both colostra: 70.7% of the polar lipids in donkey colostrum and 50.9% in bovine colostrum. Phosphatidylethanolamine (13.6% vs. 21.9%) and phosphatidylcholine (8.89% vs. 10.8%) followed.

In absolute terms, all 11 subclasses were significantly higher in bovine colostrum (p < 0.001). Only seven of the 206 individual lipids were higher in donkey colostrum, including four sphingomyelins.

Limitations of the study

• Two farms, two animal species: Donkey mares and cows came from different farms with different feeding and slightly different sampling periods (0–5 vs. 1–5 days). Differences can therefore not be attributed solely to the animal species. How the three samples per group were combined is not described in detail.
• Fold change inconsistently defined: According to the methods section, the fold change is donkey divided by cow. Since all 141 lipids were higher in bovine colostrum, the values should be below 0.5; however, 224.855 is given as the highest and 3.4735 as the lowest value, so apparently cow divided by donkey.
• Counts are not entirely consistent: Among the 141 lipids, no phosphatidylinositol is found in the enumeration, although this subclass was also higher in bovine colostrum. The abstract mentions six, the conclusion eight metabolic pathways; the multivariate analysis is attributed to different programs in the methods section and the results section. Figure 2 gives the unit as ng/mL with the addition of (w/w).
• Hardly any numbers in the main text: Absolute concentrations are only shown in box plots, not tabulated; quantity proportions are only available as numbers for three subclasses. A numerical value for the total amount of polar lipids is missing.
• Interpretations not verified: The authors' statements about the importance of individual lipids for development, energy metabolism or infant nutrition are based on literature and were not investigated in the study. It is a pure composition analysis without testing effects in humans.

Level of evidence: Basic research (laboratory) – describes properties of milk, no statement about effects in humans.

Our assessment

The study analytically describes which polar lipids occur in colostrum from donkey mares and cows and how their proportions differ. It concerns colostrum from the first days, not mature milk; statements about effects or individual commercial products cannot be derived from it.

Source: Zhang Y., Chen J., Liu Z., Zhang S., Wang J., Shao J., Yue X., Li M. (2025). Lipidomics profile shows differences of polar lipids between donkey and bovine colostrum: a comparative study. Food Chemistry: X. DOI: 10.1016/j.fochx.2025.102798 · Summarized by the DON DONKEY'S editorial team, as of October 2026.

End of the study summary. The study was conducted independently by DON DONKEY'S® and does not refer to our products. Our donkey milk is a food.