Progress 07/01/07 to 06/30/11
Outputs
OUTPUTS: This project is a continuation of NEV053BS "Long term contraception in feral horse: Efficacy, safety and behavior". The contraceptive component of the field research is ongoing. Five years of data have been collected with plans for data collection in 2011. Weekly monitoring for contraceptive efficacy and band fidelity occurred from February to December. A description of the results and how to perform behavioral data collection was discussed in ANSC 455 Domestic Animal Behavior and Welfare. Data was collected and summarized for the year. Several publications have been prepared for publication in 2011. PARTICIPANTS: David Thain, State Extension Veterinarian, Animal Biotechnology, UNR, Reno, NV Meeghan Gray, Postdoctoral Researcher, Animal Biotechnology, UNR, Reno, NV Elissa Cameron, Associate Professor, Director, Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Pretoria 0002, South Africa Phil Larussa, State Veterinarian, NV. Dept. of Agriculture (NDA), Reno, NV Lowell Miller, USDA, APHIS, WLS, NWRL, Fort Collins, CO Gary Killian, USDA, APHIS, WLS, NWRL, Fort Collins, CO TARGET AUDIENCES: The project results and the behavioral data collection techniques were discussed in the class ANSC 455 Domestic Animal Behavior and Welfare. A variety of other groups will benefit from this project. Wild and feral horse protection advocates, State Depts. of Wildlife, Agriculture, and Natural Resources, Federal agencies like Forest Service and BLM, and livestock producers may be able to utilize our findings in feral/wild horse management practises. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
While we found that both contraceptives were effective in the first four years of treatment, but in this last year, we found most treated females returned to fertility. While we anticipated that most females would return to fertility by five year post-treatment, out results validated the use of these formulations and demonstrated the ability of reversal. We will continue to monitor these mares next year, and these results support the use of these contraceptive formulations for large scale population control studies, and an effort has been made to the BLM to incorporate the use of these formulations into their management programs. These injections would be beneficial for long term population control in large populations because they reduce the need for gathers for treatments. To date, we have not found significant evidence of long term side-effects to females that return to fertility. Again, these data support the notion that these formulations are safe and effective.
Publications
- Gray, M.E and Cameron, E.Z. (2010). Does contraceptive treatment in wildlife result in side effects A review of quantitative and anecdotal evidence, Reproduction, 139:145-155. Gray, M.E., Thain, D.S., Cameron, E.Z., and Miller, L.A. (2010). Multi-year fertility reduction in free-roaming feral horses with single-injection immunocontraceptive formulations, Wildlife Research, 37:475-481.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: This project is a continuation of NEV053BS "Long term contraception in feral horse: Efficacy, safety and behavior". The contraceptive component of the field research is ongoing. Four years of data have been collected with plans for data collection in 2010. Efficacy monitoring occurred weekly from February to December. All behavioral data was analyzed and published in a dissertation. The PhD student completed her dissertation in May 2009 and successfully defended her research. She also consulted on a new project that addresses behavioral side effects of contraception in feral horses, by making recommendations for methods. Our results have been submitted for publication and also presented at local public outreach events. PARTICIPANTS: David Thain, State Extension Veterinarian, Animal Biotechnology, UNR, Reno, NV, Meeghan Gray, Postdoctoral Researcher, Animal Biotechnology, UNR, Reno, NV, Elissa Cameron, Associate Professor, Director, Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Pretoria 0002, South Africa, Phil Larussa, State Veterinarian, NV. Dept. of Agriculture (NDA), Reno, NV, Michael Holmes, Virginia Range Estray Horse Manager, NDA, Carson City, NV, Lowell Miller, USDA, APHIS, WLS, NWRL, Fort Collins, CO, Gary Killian, USDA, APHIS, WLS, NWRL, Fort Collins, CO TARGET AUDIENCES: There are several target audiences 1. Virginia Highlands homeowners have serious concerns regarding any populaton control measures of feral horses. We hope to expand their knowledge of population dynamics and thus change their opinions on contraceptive control measures. Once opinions and perceptions change more widespread use of contraceptives may become a reality. 2. Feral and wild horse managers will benefit from our research in that they will be afforded new tools for population management through these forms of contraception. 3. The general public will learn the benefits of contraceptives and thus be more open to feral and wild horse management. PROJECT MODIFICATIONS: This project is a continuation of NEV053BS "Long term contraception in feral horse: Efficacy, safety and behavior".
Impacts
Reduction of free-ranging horses by limiting fertility holds the greatest promise for economic, humane and effective population control. Contraception in feral horses should be safe and potentially reversible, cost effective, efficacious for several years with minimal handling required, and should not affect normal reproductive and harem maintenance behavior. Long-acting contraceptive approaches are urgently needed for feral horse population control. We have found that both of the contraceptive formulations significantly reduced fertility in all four years, suggesting that one injection was effective for up to four years. Some treated females have returned to fertility, but most treated females have remained infertile for four years post-treatment. These injections would be beneficial for long term population control in large populations because they reduce the need for gathers for treatments. We discovered that monitoring females year-round increased our ability to detect early foal death or pregnancy loss, which is a method not normally used in efficacy studies, potentially inflating their results. Our results also showed minimal behavioral changes in treated females as it relates to mare-stallion relationships. We saw no adverse side-effects from either contraceptive treatment as treated and control females had similar social behavior. This study will add significantly to the understanding of the behavioral side effects and duration of two different long-term immunocontraceptive products, and provides further evidence that these formulations are safe and long-acting with the use of one injection.
Publications
- Gray, M.E. 2009. An infanticide attempt by a free-roaming feral stallion (Equus caballus). Biology Letters, 5:23-25.
- Gray, M.E. 2009. The influence of reproduction and fertility manipulation on the social behavior of feral horses (Equus caballus). PhD dissertation, University of Nevada, Reno, 240pp.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: This project is a continuation of NEV053BS "Long term contraception in feral horse: Efficacy, safety and behavior". The contraceptive component of the field research is ongoing. Three years of data have been collected with plans for data collection in 2009. The behavioral component of the research was finished at the end of August 2007. A total of 307.4 hours of behavioral data were taken from January-August of 2007. These data were taken from 44 different bands and comprised of 71 different focal mares and 40 different stallions. From these bands, detailed behavioral data were collected, along with fecal samples and body condition scores. Efficacy data (foaling rates) were taken during the foaling season, and these data will continue to be taken in the spring of 2009. Currently, behavioral data are being transformed and analyzed and will be submitted for publication before the end of the year. Efficacy data are also being analyzed and written up. Several milestones took place with the lab component of research. Over 1100 fecal samples that were collected over the last 3 years were analyzed for hormones at the endocrinology lab at the St. Louis Zoo for both male and female adults. Females were tested for progesterone levels to determine cycling patterns and to assess pregnancy on females that were not seen with a foal. We also looked at how contraception may impact estrous cycles. Females were also tested for testosterone and estrodiol, to look at any impacts of contraception on these hormones. Males were tested for testosterone to detect any seasonal effects or changes due to the treatment status of females within the band. Selected males and females were tested for cortisol to see if any differences existed in stress levels based on contraceptive treatment. We also conducted an ACTH stimulation to verify the cortisol results. All of the fecal samples have been tested for hormones and these data are being analyzed. Progress was made on the genetics of the population and the PCR conditions were optimized for extracted fecal DNA. Only offspring need to be further analyzed and those data will be used to look at paternity and population genetics. PARTICIPANTS: David Thain, Animal Biotechnology, UNR, Reno, Nevada Meeghan Gray, PhD student, UNR, Reno, Nevada Elissa Cameron, Associate Professor, Director, Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Pretoria 0002, South Africa Phil Larussa, State Veterinarian, NV. Dept. of Agriculture (NDA), Reno, NV Michael Holmes, Virginia Range Estray Horse Manager, NDA, Carson City, NV Lowell Miller, USDA, APHIS, WLS, NWRL, Fort Collins, CO Gary Killian, USDA, APHIS, WLS, NWRL, Fort Collins, CO TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: This project is a continuation of NEV053BS "Long term contraception in feral horse: Efficacy, safety and behavior".
Impacts
Reduction of free-ranging horses by limiting fertility holds the greatest promise for economic, humane and effective population control. Contraception in feral horses should be safe and potentially reversible, cost effective, efficacious for several years with minimal handling required, and should not affect normal reproductive and harem maintenance behavior. To date, reproductive control by injectable immunocontraceptive formulations, principally the PZP formulation, has not shown consistent effectiveness for more than 1-2 years, and involves much expense, manpower, and horse handling to maintain infertility. Long-acting contraceptive approaches are urgently needed for feral horse population control. This study will add significantly to the understanding of the behavior effects and duration of two different long-term immunocontraceptive products. Either product will potentially add an economical tool for range management of wild and feral horse populations.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: The contraceptive component of the field research is ongoing. Two years of data have been collected with plans for data collection in 2008 and 2009. Pen trials evaluation of contraceptives are entering the fifth year with encouraging results for the PZP and GnRh products. The behavioral component of the research was finished at the end of August 2007. A total of 307.4 hours of behavioral data were taken from January-August of 2007. These data were taken from 44 different bands and comprised of 71 different focal mares and 40 different stallions. From these bands, detailed behavioral data were collected, along with fecal samples and body condition scores. Efficacy data (foaling rates) were taken during the foaling season, and these data will continue to be taken in the spring of 2008. Currently, behavioral data are being transformed and analyzed and will be submitted for publication before the end of the year. Efficacy data are also being analyzed and written up. Several
milestones took place with the lab component of research. Over 1100 fecal samples that were collected over the last 3 years were analyzed for hormones at the endocrinology lab at the St. Louis Zoo for both male and female adults. Females were tested for progesterone levels to determine cycling patterns and to assess pregnancy on females that were not seen with a foal. We also looked at how contraception may impact estrous cycles. Females were also tested for testosterone and estrodial, to look at any impacts of contraception on these hormones. Males were tested for testosterone to detect any seasonal effects or changes due to the treatment status of females within the band. Selected males and females were tested for cortisol to see if any differences existed in stress levels based on contraceptive treatment. We also conducted an ACTH stimulation to verify the cortisol results. All of the fecal samples have been tested for hormones and these data are being analyzed. Progress was made
on the genetics of the population and the PCR conditions were optimized for extracted fecal DNA. Only offspring need to be further analyzed and those data will be used to look at paternity and population genetics.
PARTICIPANTS: David Thain, Animal Biotechnology, UNR, Reno, Nevada Meeghan Gray, PhD student, UNR, Reno, Nevada Elissa Cameron, Associate Professor, Director, Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Pretoria 0002, South Africa Phil Larussa, State Veterinarian, NV. Dept. of Agriculture (NDA), Reno, NV Michael Holmes, Virginia Range Estray Horse Manager, NDA, Carson City, NV Lowell Miller, USDA, APHIS, WLS, NWRL, Fort Collins, CO Gary Killian, USDA, APHIS, WLS, NWRL, Fort Collins, CO
Impacts
Reduction of free-ranging horses by limiting fertility holds the greatest promise for economic, humane and effective population control. Contraception in feral horses should be safe and potentially reversible, cost effective, efficacious for several years with minimal handling required, and should not affect normal reproductive and harem maintenance behavior. To date, reproductive control by injectable immunocontraceptive formulations, principally the PZP formulation, has not shown consistent effectiveness for more than 1-2 years, and involves much expense, manpower, and horse handling to maintain infertility. Long-acting contraceptive approaches are urgently needed for feral horse population control. This study will add significantly to the understanding of the behavior effects and duration of two different long-term immunocontraceptive products. Either product will potentially add an economical tool for range management of wild and feral horse populations.
Publications
- No publications reported this period
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