Seasonal changes in the quality indicators of milk by cows of the Ayrshire breed in the conditions of the Vologda region

The article presents the studies’ results of milk quality indicators: fat mass fraction, protein mass fraction, urea and the number of somatic cells by cows of the Ayrshire breed in the Vologda region in 2021. Samples of cow’s milk were taken in accordance with the monthly control milking schedule and tested on the Combi-Foss infrared spectrometer from the Danish company Foss. From the data obtained, a research base was formed, and then a comparative characteristic of the quality indicators of milk was carried out, taking into account the season of the year. Based on the results of the studies, it was revealed that all indicators for the period under review are within the normal range, comply with Russian standards and correspond to the average statistical data for the Ayrshire breed. In the autumn season, fat mass fraction (FMF) and protein mass fraction (PMF) are higher compared to the rest and are 5.00% and 3.70%, respectively. The content of urea in milk in the autumn period is optimal (20.06 mg/100 ml), and the number of somatic cells 194 thousand/ cm3 corresponds to the highest grade. In the spring and summer seasons, there is a deterioration in quality indicators in cow’s milk.