Long-term effect of a GnRH-based immunocontraceptive on feral cattle in Hong Kong.

Increasing human-wildlife conflicts worldwide are driving the need for multiple solutions to reducing "problem" wildlife and their impacts. Fertility control is advocated as a non-lethal tool to manage free-living wildlife and in particular to control iconic species. Injectable immunocontr...

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Main Authors: Rebecca Pinkham, Ka-Kei Koon, Jason To, Jason Chan, Flavie Vial, Matt Gomm, Douglas C Eckery, Giovanna Massei
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0272604
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author Rebecca Pinkham
Ka-Kei Koon
Jason To
Jason Chan
Flavie Vial
Matt Gomm
Douglas C Eckery
Giovanna Massei
author_facet Rebecca Pinkham
Ka-Kei Koon
Jason To
Jason Chan
Flavie Vial
Matt Gomm
Douglas C Eckery
Giovanna Massei
author_sort Rebecca Pinkham
collection DOAJ
description Increasing human-wildlife conflicts worldwide are driving the need for multiple solutions to reducing "problem" wildlife and their impacts. Fertility control is advocated as a non-lethal tool to manage free-living wildlife and in particular to control iconic species. Injectable immunocontraceptives, such as GonaCon, stimulate the immune system to produce antibodies against the gonadotrophin-releasing hormone (GnRH), which in turn affects the release of reproductive hormones in mammals. Feral cattle (Bos indicus or Bos taurus) in Hong Kong are an iconic species whose numbers and impacts on human activities have increased over the last decade. Previous studies have proven that a primer vaccination and booster dose of GonaCon in female cattle are safe and effective in reducing pregnancy levels one year post-treatment. The aims of this project were 1. to evaluate the longevity of the effect of GonaCon in feral cattle up to four years post-vaccination; and 2. to assess if a second booster dose of GonaCon, administered at either two or four years post-vaccination, extends the contraceptive effect in this species. Vaccination with GonaCon, administered as a primer and booster dose, was effective in causing significant infertility in free-living cattle for at least three years post-vaccination, with the percentage of pregnant animals in the vaccinated group decreasing from 76% at vaccination to 35%, 19% and 7% in years 2, 3 and 4 post-vaccination, compared with 67% at vaccination to 50%, 57% and 14% respectively in the control group. A second booster dose of GonaCon administered either 2 or 4 years after vaccination rendered 100% of the Treated cattle infertile for at least another year. These results suggested that vaccination with GonaCon can reduce feral cattle population growth and that a second booster dose can extend the longevity of the contraceptive effect.
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spelling doaj.art-4dc93b889e0b49298ed2a21eb359f4d22022-12-22T04:25:10ZengPublic Library of Science (PLoS)PLoS ONE1932-62032022-01-01178e027260410.1371/journal.pone.0272604Long-term effect of a GnRH-based immunocontraceptive on feral cattle in Hong Kong.Rebecca PinkhamKa-Kei KoonJason ToJason ChanFlavie VialMatt GommDouglas C EckeryGiovanna MasseiIncreasing human-wildlife conflicts worldwide are driving the need for multiple solutions to reducing "problem" wildlife and their impacts. Fertility control is advocated as a non-lethal tool to manage free-living wildlife and in particular to control iconic species. Injectable immunocontraceptives, such as GonaCon, stimulate the immune system to produce antibodies against the gonadotrophin-releasing hormone (GnRH), which in turn affects the release of reproductive hormones in mammals. Feral cattle (Bos indicus or Bos taurus) in Hong Kong are an iconic species whose numbers and impacts on human activities have increased over the last decade. Previous studies have proven that a primer vaccination and booster dose of GonaCon in female cattle are safe and effective in reducing pregnancy levels one year post-treatment. The aims of this project were 1. to evaluate the longevity of the effect of GonaCon in feral cattle up to four years post-vaccination; and 2. to assess if a second booster dose of GonaCon, administered at either two or four years post-vaccination, extends the contraceptive effect in this species. Vaccination with GonaCon, administered as a primer and booster dose, was effective in causing significant infertility in free-living cattle for at least three years post-vaccination, with the percentage of pregnant animals in the vaccinated group decreasing from 76% at vaccination to 35%, 19% and 7% in years 2, 3 and 4 post-vaccination, compared with 67% at vaccination to 50%, 57% and 14% respectively in the control group. A second booster dose of GonaCon administered either 2 or 4 years after vaccination rendered 100% of the Treated cattle infertile for at least another year. These results suggested that vaccination with GonaCon can reduce feral cattle population growth and that a second booster dose can extend the longevity of the contraceptive effect.https://doi.org/10.1371/journal.pone.0272604
spellingShingle Rebecca Pinkham
Ka-Kei Koon
Jason To
Jason Chan
Flavie Vial
Matt Gomm
Douglas C Eckery
Giovanna Massei
Long-term effect of a GnRH-based immunocontraceptive on feral cattle in Hong Kong.
PLoS ONE
title Long-term effect of a GnRH-based immunocontraceptive on feral cattle in Hong Kong.
title_full Long-term effect of a GnRH-based immunocontraceptive on feral cattle in Hong Kong.
title_fullStr Long-term effect of a GnRH-based immunocontraceptive on feral cattle in Hong Kong.
title_full_unstemmed Long-term effect of a GnRH-based immunocontraceptive on feral cattle in Hong Kong.
title_short Long-term effect of a GnRH-based immunocontraceptive on feral cattle in Hong Kong.
title_sort long term effect of a gnrh based immunocontraceptive on feral cattle in hong kong
url https://doi.org/10.1371/journal.pone.0272604
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