<b>Environmental and handling factors on the chemical composition of milk in dairy farms of Paraná State, Brazil</b> - doi: 10.4025/actascianimsci.v32i3.8570

Abstract

The objective of this research study was to evaluate the influence of total diet chemical composition and environment factors of the different seasons of the year on the chemical composition of milk. The milk farms evaluated were classified as Farm 1 (G1) and Farm 2 (G2). The study defined as treatments the four seasons of the year and the milk production system (G1 and G2). A total of 34 diet samples were collected, fed to lactating animals in order to analyze the chemical-bromatological composition, and 20 samples of raw milk straight from cows in order to evaluate the chemical composition of milk during the four seasons. For data statistical analyses, the method of least squares was used. There was a difference (p < 0.05) between the G1 and G2 farms, for milk production (kg day^-1), fat, protein and milk urea nitrogen (MUN) percentages. However, no difference was observed (p > 0.05) in lactose and total solids percentage between the studied farms. On the other hand, it was observed that the production (kg day^-1) and all analyzed milk components were different (p < 0.05) during the four seasons of the year. The results demonstrate that the total diet chemical composition, lactation phases and environments factors of seasons of the year may cause variation in milk production and chemical composition.