Immunocontraception of male and female giraffes using the GnRH vaccine Improvac®

Autor: Franz Schwarzenberger, Christina Geiger, Eva Martinez Nevado, Nicole Schauerte, Folko Balfanz, Florian Sicks, Anna Hein, Christine Kaandorp-Huber, Gwendoline Anfray, Sandra Marcordes, Tobias Knauf-Witzens, Sophia-Maria Jeserschek, Pia Krawinkel, Betina Venshøj
Rok vydání: 2021
Předmět:
Zdroj: Zoo Biology. 41:50-64
ISSN: 1098-2361
0733-3188
Popis: The aim of this study was to develop protocols for contraception in both sexes of giraffes (Giraffa camelopardalis) by using the GnRH vaccine Improvac®. We evaluated the success of immunization by analyzing fecal reproductive hormone metabolites in female (n = 20) and male (n = 9) giraffes. Endocrine analysis provided the basis for the successful immunization protocol, as well as for assessing long-term effects. Reliable reduction of fecal steroid metabolites to baseline levels in female giraffes was achieved with three, and in males with four or five injections at 4-week intervals. Effective booster injections were administered at 2-month intervals in the first year of treatment and at three to 4-month intervals in the following years. In addition to endocrine analysis, we determined vaccination efficacy in bulls by assessing testicular atrophy. Long-term (>2 years) use in females was often accompanied by prolonged periods of persistent corpus luteum activity, although normal cycles were not observed. Problems might occur with reversibility, because in a few males and females, even after more than 2 years since treatment had been stopped, fecal hormone metabolites have not returned to pretreatment levels. The results are somewhat ambiguous, as reproduction can be suppressed by use of Improvac®, but the question of reversibility remains unsolved.
Databáze: OpenAIRE
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