Abstract
An enzyme-linked immunosorbent assay (ELISA) for quantitation of antibodies, following immunization with an experimental
Salmonella typhimurium vaccine in two postpartum breeds of ewes, was standardized. Based on analysis of variance, the two breeds of ewes, purebred Awassi and crossbred Finn × Texel × Awassi (FTA), did not differ in the ELISA-antibody levels following immunization with an experimental formalin inactivated oil based
S. typhimurium vaccine (
P > 0.05). However, vaccination in both breeds resulted in higher significant antibody level than unvaccinated ewes. The antibody level quantitated in both breeds increased significantly at 2 weeks after the first immunization (
P < 0.01), then decreased slightly 3 weeks later, in spite of a booster administration at 2 weeks after the first immunization. Seroconversion at 2 weeks after the first immunization was 66.7% in each breed (
P > 0.05); however, it increased to 100% at 3 weeks after the booster in Awassi ewes, while it was maintained at 66.7% in the FTA ewes. This work implies the ability of the administered vaccine to induce antibody response in both ewe breeds that could be quantified by the developed ELISA.