Factors associated with colostrum immunoglobulin G concentration in northern-Victorian dairy cows

Abstract

Objectives: To determine the proportion of first-milking colostrum samples produced on four northern-Victorian dairy farms that meet industry standards in terms of immunoglobulin G (IgG) concentration and to identify risk factors that affect colostrum quality. Methods: Colostrum IgG concentrations from 442 dairy cows on four farms were estimated using a Brix refractometer and risk factors for colostrum IgG concentration were determined using multivariable logistic regression. Results: Only 39% of samples met the definition of high quality. The strongest predictor for colostrum quality was the interval from calving to colostrum harvesting. Colostrum harvested from cows within 12 h of calving ..