Volume: 5, 2026
5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: H011
DOI: https://doi.org/10.24326/ICDSUPL5.H011
Published online: 22 April 2026
Comparison of the content of functional peptides with health-promoting effects in goat milk from the summer and winter seasons
Anna Lipian-Głos*1, Magdalena Krauze1, Anna Stępniowska1, Bartosz Sołowiej2, Ramutė Mišeikienė3, Paulius Matusevičius4 and Katarzyna Ognik1
1 Department of Biochemistry and Toxicology, University of Life Sciences in Lublin, 13 Akademicka St., 20-950, Lublin, Poland
2 Department of Animal Food Technology, University of Life Sciences in Lublin, 8 Skromna St., 20-704 Lublin, Poland
3 Institute of Biology Systems and Genetic Research, Lithuanian University of Health Sciences, Kaunas, Lithuania
4 Department of Animal Nutrition, Lithuanian University of Health Sciences, 9 A. Mickeviciaus St., 47-181 Kaunas, Lithuania
Corresponding author: anna.lipian@up.edu.pl
The aim of the study was to compare the content of functional peptides in organic summer and winter goat milk. The material was milk from goats raised on an organic farm in southeastern Poland. A total of 136 milk samples were collected in the winter of 2024 and the summer of 2025. In the summer, feeding was based on pasture grazing. Cows in mid-lactation were selected for sampling. The following plant species dominated Anthoxanthum odoratum, Dactylis glomerata, Trifolium pratensis, Poa pratensis, Ranunculus acris, Alopecurus pratensis, Lathyrus pratensis, Geranium pratensis, Alchemilla monticola, Carum carvi, Polygala vulgaris, Leucanthemum vulgare, Plantago media, Platenthera biolia and Trisetum flavescens. Outside the summer season, the animals were fed ad libitum with feed prepared on the farm. The feed consisted of haylage made from hay harvested from the pastures where grazing took place during the summer season. By using immunoenzymatic methods and liquid chromatography, selected functional peptides and total protein levels were determined.
The protein content of the goats’ milk in the summer season was 3.33-3.41 g/100 mL, while in the winter season it was 3.28-3.34 g/100 mL. The content of casein, β-lactoglobulin, β-lactoferrin, and lysozyme in the milk was calculated per 100 g of protein (the protein level used for the calculation was 3.34 g/100 mL). Analysis showed that the summer goats’ milk contained 10% less casein than the winter milk. The summer goats’ milk also contained 6% less β-lactoglobulin, 7% less α-lactalbumin, and 6% less lactoferrin. Summer milk showed higher levels of casokinin (12%) and colostrinin (13%) and lower casienomacropeptide (9%) and β-casomorphin (5%). In the case of lysozyme and ceruloplasmin, summer milk contained 12% and 14% more of these peptides, respectively, than winter milk. Based on the obtained results, it can be concluded that the feeding season of goats influences the levels of functional peptides, particularly casein, casienomacropeptide, colostrinin, and ceruloplasmin.
Research Network of Life Sciences Universities for the Development of the Polish Dairy Sector – research project is financed under a special-purpose subsidy from the Minister of Education and Science (MEiN/2023/DPI/2862).
Keywords: biologically active peptides; feeding season; goat milk; health-promoting; nutritional
How to cite
Lipian-Głos A., Krauze M., Stępniowska A., Sołowiej B., Mišeikienė R., Matusevičius P., Ognik K., 2026. Comparison of the content of functional peptides with health-promoting effects in goat milk from the summer and winter seasons. In: 5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL5.H011