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Die indusering van geslagsaktiwiteit by Angorabokke deur middel van heteroseksuele kontak
Proefskrif (M. Sc. Agric.) -- Universiteit van Stellenbosch, 1990.
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| Format: | Thesis |
| Language: | Afrikaans |
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Stellenbosch : Stellenbosch University
2012
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| _version_ | 1867614133164179456 |
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| access_status_str | Open Access |
| author | Diedericks, Johan Christiaan |
| author2 | Coetzer, W. A. |
| author_browse | Coetzer, W. A. Diedericks, Johan Christiaan |
| author_facet | Coetzer, W. A. Diedericks, Johan Christiaan |
| author_sort | Diedericks, Johan Christiaan |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Proefskrif (M. Sc. Agric.) -- Universiteit van Stellenbosch, 1990. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/68732 |
| institution | Stellenbosch University (South Africa) |
| language | Afrikaans |
| last_indexed | 2026-06-10T12:47:10.728Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2012 |
| publishDateRange | 2012 |
| publishDateSort | 2012 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/68732 Die indusering van geslagsaktiwiteit by Angorabokke deur middel van heteroseksuele kontak Diedericks, Johan Christiaan Coetzer, W. A. Van Niekerk, C. H. Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Science. Angora goat -- Reproduction Animal breeding Sexual behavior in animals Dissertations -- Physiology (Human and animal) Proefskrif (M. Sc. Agric.) -- Universiteit van Stellenbosch, 1990. The purpose of this study was to investigate the effect of heterosexual contact on a physio-endocrinological and reproductive basis in the Angora goat. The study was executed in two phases, viz during the anestrous period (October–December 1988) and after that in the active breeding season (March–April 1989) of the Angora goat. The does were divided into two groups. The one group was exposed to sexually active rams (stimulated group), while the control group had no ram contact before or during the trial period. Blood samples were taken for progesterone and LH determination, while eight does were slaughtered for macroscopic observation of their ovaria. During the anoestrous period the low libido, or absence thereof, in the Angora rams were eliminated through hormonal treatments and heterosexual contact. Gonadotropin Releasing Hormone (Gn-RH) and Depo-testosterone were successful in inducing sexual activity in the rams. The control rams which only had contact with sexually active does were also stimulated to sexual activity. It seems that heterosexual contact plays a dominating role in the stimulation of sexual activity and the desired effect can even be reached without hormonal therapy. During the anestrous period the average plasma progesterone concentration of the stimulated does showed little variation and the basal progesterone levels were maintained. The first does of the stimulated group showed oestrus only seven days after ram introduction. Furthermore, the ovaria of the does which were slaughtered just before ram introduction had no corpora lutea, but they displayed follicles bigger than 3 mm in the ovaria. These results are possible indications that although the does were in anestrus before ram introduction, they were ready to start cyclic activity. During this study it was found that the LH peaks occurred between 12 and 30 hours after commencement of the estrous period. The LH peaks were accompanied by estrus and it seems that the Angora goat has no silent ovulation as occurs in sheep. During the breeding season it was established that the does reacted sooner and more easily to external stimuli from rams, as the peak of the breeding season (April/May) approached. This may be the reason why some does immediately showed estrus and were successfully served shortly after ram introduction. It was also found that Angora does will eventually start cycling during the active breeding season without direct stimulation by the rams. The hundred per cent lambing rate which was achieved outside the normal breeding season is an indication that a Spring mating season for Angora goats, although against all expectations, is a practical possibility. Masters 2012-08-27T12:26:44Z 2012-08-27T12:26:44Z 1990 Thesis http://hdl.handle.net/10019.1/68732 af Stellenbosch University 108 pages : ill. application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Angora goat -- Reproduction Animal breeding Sexual behavior in animals Dissertations -- Physiology (Human and animal) Diedericks, Johan Christiaan Die indusering van geslagsaktiwiteit by Angorabokke deur middel van heteroseksuele kontak |
| title | Die indusering van geslagsaktiwiteit by Angorabokke deur middel van heteroseksuele kontak |
| title_full | Die indusering van geslagsaktiwiteit by Angorabokke deur middel van heteroseksuele kontak |
| title_fullStr | Die indusering van geslagsaktiwiteit by Angorabokke deur middel van heteroseksuele kontak |
| title_full_unstemmed | Die indusering van geslagsaktiwiteit by Angorabokke deur middel van heteroseksuele kontak |
| title_short | Die indusering van geslagsaktiwiteit by Angorabokke deur middel van heteroseksuele kontak |
| title_sort | die indusering van geslagsaktiwiteit by angorabokke deur middel van heteroseksuele kontak |
| topic | Angora goat -- Reproduction Animal breeding Sexual behavior in animals Dissertations -- Physiology (Human and animal) |
| url | http://hdl.handle.net/10019.1/68732 |
| work_keys_str_mv | AT diedericksjohanchristiaan dieinduseringvangeslagsaktiwiteitbyangorabokkedeurmiddelvanheteroseksuelekontak |