The influence of seasonal factors on daily milk production and chemical composition of milk in dairy cows

The production characteristics of dairy cows are subject to the influence of numerous environmental and management factors, among which seasonal changes play an important role. The aim of this study was to analyze the influence of the seasons on the amount of milk produced daily and the amount and proportion of milk fat and protein in the milk. Data collected during regular milk control were used, and statistical analysis was performed at the level of more than one million records for each characteristic. The results showed a pronounced seasonal variability of production parameters. The highest daily milk yields were recorded in spring and winter (23.50 kg and 23.00 kg respectively), while these values were lower in summer and autumn. The milk fat and protein content also varied depending on the season - the highest fat and protein contents were recorded in the colder months, while the lowest were recorded during summer, which can be associated with heat stress and reduced feed intake. Seasonal variability in production indicates the need for seasonally adapted herd management strategies, including ration optimization, thermal comfort, and technological adaptation. The research provides an important contribution to understanding the dynamics of production traits throughout the year and provides a basis for further modelling of effective management systems that would enable more sustainable and stable dairy farming under climate change.