Production of Antibody in Mammary Gland of Pregnant, Non-Lactating and Lactating Cows, Evoked by Polyvalent Antigen with Reference to Dosage and Frequency of Immunization.

Sixteen cows were used in a series of experiments to test dose, route and frequency responses in the production of milk and serum agglutinins to a spectrum of 9 proven bovine pathogens. The bacterial species were: Pasteurella multocida (2 isolates), Escherichia coli, Staphylococcus aureus, Staphylococcus albus, Streptococcus sp., Corynebacterium sp., Salmonella enteriditis, and Aerobacter aerogenes. Primary immunizations were made either through the teat canal or intramuscularly. "Booster" injections were made through the teat canal. Agglutinins in the blood appeared only after a week or more. In the milk, titers were recorded in 1 or 2 days following primary immunization. Variation of titer in the blood and milk was somewhat independent. In all but 1 cow, antibody was produced against each organism in milk and blood serum. Udder inflammation was observed in the experiments when a 15-day interval separated immunizations. Inflammation was minimal in the experiments employing the 7-day interval of immunization. A positive Whiteside test was observed following most injections, even where no other clinical signs of reaction were seen. The findings are discussed in relation to the previous literature.