Evaluation of one-shot vaccination protocol for suppressing reproductive functions in rams using encapsulated ovalbumin-LHRH-7 protein.

Abstract

The objective of study were to determine the effectiveness of Ovalbumin-LHRH-7 (OL) protein administered with cytosine guanine (CpG) adjuvant and Incomplete Freund’s Adjuvant (IFA), and used one-shot immunization (single-dose vaccination) protocol in which booster dose included in microspheres in rams. Fifty ram lambs at about a year old were used. Treatment groups receiving Ovalbumin LHRH and control contained 10 animals. They were stratified according to age (weeks), live weight and scrotal circumference size, and were randomly assigned to five groups. Scrotal circumference, sexual activities and the numbers of rams having sperm in the ejaculate were affected from treatment (P less than 0.05) depending on the dose and vaccination protocol. However, immunization did not affect live weight changes in any treatment groups (P>0.05). Findings clearly demonstrate that the effects of OL immunization on reproductive traits in yearling rams were prominent when it was administered at higher dose and classical one primary and one booster immunization as free protein form. Also we observed that the effect of higher and single dose of OL protein in encapsulated form on reproductive traits had the partial suppressing. CpG adjuvant along with IFA was proved to be an effective adjuvant and could be suggested to be used and alternative to FCA in hormone immunization.