Effects of Novel Oral and Plasmid-Injected KISS1 DNA Vaccines on Immunocastration and in Inhibiting Mutton Odour of Male Goats

Abstract

This study analysed the effect of novel oral and plasmid-injected KISS1 DNA vaccines on immunocastration and in inhibiting mutton odour of male goats. In this study, 20 male goats aged eight weeks were randomly divided into the oral and plasmid-injected KISS1. DNA vaccine groups (groups T1 and T2) and the empty vector groups (groups C1 and C2) for immunisation. Blood samples were collected at 0, 3, 6, 10 and 14 weeks after primary immunisation for the detection of kisspeptin antibodies and testosterone by indirect enzyme-linked immunosorbent assay. Scrotal circumference was detected from week 0 to week 14 after primary immunisation, and the testes were weighed at week 14 after primary immunisation after slaughter. The concentrations of 4-methyloctanoic acid and 4-methylnonanoic acid in waist subcutaneous adipose tissue were detected using gas chromatography. Immunisation of oral and plasmid-injected KISS1 DNA vaccines induced strong antibody response, significantly suppressed testosterone secretion and reduced scrotal circumference and testis weight. It also significantly reduced the concentrations of 4-methyloctanoic acid and 4-methylnonanoic acid in adipose tissue. These findings indicated that immunisation of oral and plasmid-injected KISS1 DNA vaccines can effectively suppress testosterone secretion, testis growth and mutton odour, and the novel oral KISS1 DNA vaccine is more promising in the large-scale preparation of immunocastration vaccines because of simple operations and low cost.