Experimental neonatal colibacillosis in cows: serological studies

Abstract

Serological studies of passive immunity in experimentally induced bovine colibacillosis was studied in a 41-cow university herd. Pregnant dams were antigenized prepartum with two injections administered by the subcutaneous and intrammamary routes with one of four vaccine preparations (killed bacteria, live bacteria, culture supernatant, or heart infusion broth [control]). The data indicate that 77% of the neonates born to vaccinated dams were strongly protected against oral challenge with Escherichia coli strain B-44. Bacterial agglutinin and passive hemagglutination titers of colostral whey directly reflected the efficacy of the vaccines. A notable decrease in the whey titers to somatic and capsular antigens occurred after heat treatment at 56 C for 30 min. Complicity of heat-liable immune factor(s) in protection from scouring was suggested. The nature of the protective antigen is not clearly defined by these studies but there is some evidence that the K antigen may play a vital role in this regard.

Immunological activities of milk

“…In domestic species Haelterman (1965) showed that immune milk protected sucking pigs from TGE infection, while Wilson and Jutila (1975) Although in many cases the protection ascribed to milk has been shown to be immune in nature, care must be taken not to attribute all the protective effects of suckling to the immune system. It has been shown, for example, that a major advantage of breast feeding of infants when compared to formula feeding lies in the low buffering capacity of breast milk compared with cow's milk, which lowers the pH of the upper small intestine and so inhibits the multiplication of coliforms (Bullen & Willis, 1971), and milk contains many bacteriostatic agents, such as Iysozyme lactoferrins and lactoperoxidase (reviewed by Reiter, 1978) which may also be important in protection.…”

Experimental neonatal colibacillosis in cows: immunoglobin classes involved in protection

“…In a previous report we have shown that various Escherichia coli vaccines induced the formation of antibodies in preparturient bovine which protected calves against experimental neonatal colibacillosis (scours) (15,21). These data strongly suggested that protection against scours was afforded by both anti-O and anti-K antibodies acquired by the calf through the colostrum.…”