Abstract:
This study was conducted under the usual and normal conditions of herd's management rather than under defined and controlled experimental conditions. The main objective of this study was to identify cows' milkfat characteristics produced in 4 different dairy regions in Bekaa Valley, Lebanon, over one year in cold and in hot seasons. Cows' milk samples were taken once a month from each region. Principal fatty acids content (C4, C6, C8, C10, C12, C14, C16, C18:0, C18:1, C18:2) solid fat content (SFC) determined by differential scanning calorimetry (DSC) at 20°C, low melting and high melting enthalpies (J-g) were determined. Fatty acid contents, SFC, low and high melting enthalpies values showed significant differences (p0.001) between season and among the four different regions. High amounts of short chain fatty acids being related to lactation stage were found higher during the cold season, whereas variability of long-chain fatty acids seemed to be related to diets. Solid fat contents (SFC) and melting enthalpies of high melting triacylglycerols were higher during the cold season in all investigated regions except for one region where diets had major effect.