effect of egg derived specific antibody and probiotic on prevention of salmonella enteritidis infection in broiler chickens

ABSTRACT

To evaluate the effect of probiotic [Primalac] and Salmonella enteritidis-specific IgY on prevention of Salmonella enteritidis infection in broiler chickens, four 33 week-old Single Comb White Leghorn hens were hyperimmunized with Salmonella enteritidis [SE] whole cell antigens obtained by ultrasonication and administrated at a protein concentration of 500 microg/ml after centrifugation. Primary immunization was performed with 250 micro g of the antigen prepared in equal volume of Freunds complete adjuvant and saline. Booster injections were done each 14 days for twice, using incomplete Freunds adjuvant. Bleedings were performed 20 days after first injection and eggs were collected. The presence of anti-Salmonella antibody IgY and IgG in egg yolk and serum respectively, was monitored by ELISA, during the immunization period. Body weight, feed intake and feed conversation were determined. Then two hundred forty male "Ross "day-old chicks were randomly assigned to 8 groups and 3 replications of 10 birds were grown for 56 days of experiment. Eight experimental groups identified with, S, P, A, SP, SA, AP, SPA, C. Four birds from four challenged groups [S], were orally inoculated with 0.5 Ml of S. enteritids that contained 1X10[6] cfu/ml on day 7. The groups that supplemented with antibody [A], received 15 ml of yolk contained antibody [1.5 ml/bird/day], from day 1 to end of the experiment. The probiotic treated groups [P] were received probiotic, 0.1% of feed and 0.5% of feed, during 1-21 and 22-56 days of experimental period respectively. One group as control [C] did not receive any treatment of probiotic and antibody. The test was completely randomized designed. In this project the SAS statistical program for parameter data and chi[2] test for non- parameter data. The results indicated that high titer polyclonal antibody may be obtained 20 days and 55 days after first immunization, in serum and egg yolk respectively. A-treated, P-treated and A-Ptreated groups had significantly lower fecal shedding [P < 0.01]. The antibody alone and A-P treated groups had a significantly lower concentration of SE cecal colonization. Antibody alone and A-Ptreated groups had a lower isolation of SE from the liver, spleen and ileume. There were no significant differences [P > 0.05] in the mean body weight, mean daily feed intake, feed conversation ratio and mortality rate among the experimental groups at any period of experiment, but in the A-, P-, and A-P treated groups, daily weight gain significantly increased during finisher period and at day 49 [p < 0.05]