Immunization of bovines with concealed antigens from Haematobia irritans

To evaluate an immunization procedure using antigens from Haematobia irritans intestine (AgHiI), four bovines (group I) were inoculated with AgHiI mixed with Freund's incomplete adjuvant containing Lactobacillus casei, three bovines (group II) received AgHiI, and three bovines (group III) received saline solution. At day 35, blood was collected from each animal to feed H. irritans flies. There was no difference in the fly mortality observed in the three groups. The percentage of reduction of eggs oviposited by each female in 8 days (%RE), as compared with group III, was 29.45 for group I and 11.02 for group II. Antibody levels (AbL) to AgHiI were higher in group I than in groups II and III. A high correlation between %RE and AbL was observed.