Colostrum-Immunoglobulin Interrelationships in Dairy Calves ,

Abstract

Concentration of immunoglobulins in colostrum is lower in cows at first calving than in multiparous cows; however, exposure of cows to pathogens common to the environment in which calves will be reared is more critical than is parity of cows. A simple field test is available for estimating total immunoglobulin concentration in colostrum. Both the amount of colostrum fed and its immunoglobulin concentration are major factors affecting concentration in serum of calves. Considering the concentration commonly observed in colostrum, it is recommended that calves of moderate size be fed 1.5 to 2.0 liters of colostrum per feeding during the first two days of life to insure adequate protection against infection. Although the efficiency with which immunoglobulin is absorbed decreases with age, calves should receive colostrum within a few hours after birth primarily for the purpose of preventing invasion of the epithelial tissue of the intestine by bacteria or viruses during this critical period. Low serum immunoglobulin concentration in calves in herds that have overall low calf mortality has less impact on incidence of sickness and mortality than it does in herds in which the overall mortality rate is high. Prepartum vaccination of cows to enhance the concentration of antibodies against specific antigens commonly observed in enterotoxigenic Escherichia coli has been successful; however, protection is provided only against serotypes of the organism included in the vaccine.