Quantitative assessment and impact of thermal treatment on quality of Holstein dairy cattle colostrum immunoglobulin and viscosity

BackgroundBovine postpartum colostrum delivers a vital source of immunoglobulins (Igs) and other non-specific immune factors for passive transfer of immunity to newborn calves. Heat treatment of colostrum is an effective practice to reduce potential pathogens that can be transmitted to the newborn calves. Therefore, there is a need to determine optimized temperature and time that can minimally change IgG concentration and the viscosity (consistency) of colostrum. In order to preserve the quality and value of bovine postpartum colostrum, this study aimed to determine the IgG concentration, influence of different thermal treatments on the quality of colostrum and other properties including viscosity, fat and color.ResultsA total of 40 German Holstein dairy cattle first colostrum samples, collected after birth, were evaluated for color gradation, fat (%), colostrum IgG (mg mL-1), IgG (%Brix) and refractive index (nD) concentration, visual and dynamic viscosity and impact of different treatments (60 °C/60 min; 63.5°C/30 min and 72.0°C/15 s) on the viscosity. The color was graded from white-pale yellow to yellow and dark-yellowish, fat (1.4 - 8.2%) and IgG concentration (4 - 116 mg mL-1), Brix (8.5% - 35.4% Brix) and nD (1.3454 - 1.3905), respectively. The visual viscosity of first colostrum was classified into watery, liquid and thick consistency, whereas the dynamic viscosity and treated colostrum ranged from