Use of mammary gland and colostral characteristics for prediction of colostral IgG, concentration and intramammary infection in Holstein cows

Objective-To determine whether mammary gland or colostral characteristics a t carving could be used to predict colostral immunoglobulin G(1) (IgG(1)) c oncentration or intramammary infection (IMI) and whether leakage of colostr um affects IgG, concentration. Design-Prospective study. Animals-113 multiparous Holstein cows. Procedure-Cows were examined within 3 hours of calving, and mammary gland a nd colostral characteristics, colostral volume, somatic cell count, and con centrations of IgG(1), fat, and protein were determined. Bacteriologic cult ure of mammary secretions was performed approximately 14 and 7 days before calving and at calving. Associations of gland and colostral characteristics with colostral IgG(1) concentration, colostral volume, and IMI were examin ed. Results-Thick or thin colostrum had higher IgG(1) concentration than colost rum of intermediate viscosity. Colostrum from mammary glands that were firm had low IgG(1) concentration. Colostral IgG(1) concentration was weakly co rrelated with volume. Intramammary infection was likely to be detected if c olostrum contained clots or blood or if the California Mastitis Test (CMT) score was greater than or equal to 2. Somatic cell count was higher for gla nds with IMI than for uninfected glands, and CMT score was correlated with cell count. Clinical Implications-Mammary gland and colostral characteristics were of l ittle value in predicting IgG(1) concentration. Our findings do not support recommendations that first milking colostrum that is thin (watery) or that is from cows producing large volumes not be fed to dairy calves. Colostral characteristics, particularly CMT score, were of value for predicting IMI.