Effects of an Experimental Follicle-Stimulating Hormone (FSH) Vaccine on Immune, Hormonal, and Biochemical Parameters in Kaboudeh Shiraz Rams

Background: Controlling aggression, preventing unwanted matings and reducing the boar taint of male carcasses has always been one of the main challenges for livestock workers. In the past, harsh methods such as surgery were often used to solve these problems. Today, sterilization using the immune system has been considered as a non-invasive alternative. In the meantime, immunization against follicle-stimulating hormone (FSH) is considered one of the new approaches for reproductive management. This study was conducted to evaluate the immune, hormonal and biochemical responses following the injection of an experimental anti-FSH vaccine in Kaboudeh Shiraz Rams. Methods: In this experimental study, ۱۴ Kaboudeh Shiraz rams with an average age of five months and a weight of ۲۹ to ۳۶ kg were randomly divided into two control and vaccinated groups. The vaccine, a combination of FSH antigen with aluminum hydroxide (alum) adjuvant, was prepared and injected subcutaneously. Blood samples were collected at time zero (before the first injection), ۱۴ and ۲۱ days after the first vaccination. The immune response was measured using ELISA to measure anti-FSH antibody levels, serum levels of sex hormones (testosterone, FSH, LH, cortisol) and lipid profile (triglycerides, cholesterol, glucose) using commercial kits. In addition, weight was measured on days ۰, ۳۰ and ۶۰. Results: The level of anti-FSH antibody in the vaccinated group on day ۱۴ was not significantly different from the control group (p>۰.۰۵). However, on day ۲۱ after vaccination, it increased significantly compared to the control group (P<۰.۰۵). The level of testosterone on days ۱۴ and ۲۱ after vaccination did not differ significantly between the vaccinated and control groups (p>۰.۰۵). The level of FSH and LH on day ۱۴ after vaccination was not significantly different between the control and vaccinated groups (p>۰.۰۵), while on day ۲۱ after vaccination, the level of these two hormones was significantly different between the vaccinated and control groups (P<۰.۰۵). The level of cortisol on day ۱۴ after vaccination was significantly increased in the vaccinated group compared to the control group (P<۰.۰۵), and on day ۲۱ after vaccination, the level of this hormone in the vaccinated group decreased significantly compared to the control group (P<۰.۰۵). Triglyceride and cholesterol levels measured ۲۱ days after vaccination did not show any significant difference between the vaccinated and control groups (p>۰.۰۵). While blood glucose levels on day ۲۱ after vaccination in the vaccinated group were significantly higher than in the control group (P<۰.۰۵). Weight was also measured on days ۰, ۳۰ and ۶۰ and no significant difference was observed between the different experimental groups (p>۰.۰۵).