Hur påverkar inavel fruktsamheten hos häst?
Inbreeding has become a problem in some horse breeds. Studies show that it may lead to inbreeding depression which affects e.g. reproduction traits. In the wild there are mechanisms that make horses avoid mating with close relatives. When selection is done by humans this mechanism is removed and int...
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| Formato: | First cycle, G2E |
| Lenguaje: | sueco sueco |
| Publicado: |
2012
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| Acceso en línea: | https://stud.epsilon.slu.se/4310/ |
| _version_ | 1855570662911901696 |
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| author | Selinus, Hanna |
| author_browse | Selinus, Hanna |
| author_facet | Selinus, Hanna |
| author_sort | Selinus, Hanna |
| collection | Epsilon Archive for Student Projects |
| description | Inbreeding has become a problem in some horse breeds. Studies show that it may lead to inbreeding depression which affects e.g. reproduction traits. In the wild there are mechanisms that make horses avoid mating with close relatives. When selection is done by humans this mechanism is removed and intensive breeding for a few traits, for example good racing results, can become a problem. A small population may have more difficulties to maintain a large genetic diversity, for example the Friesian horse and the Hucul horse. The Friesian population has decreased substantially in number over the past hundred years and the population of the Hucul horse is small and closed. This has resulted in an increased rate of retained placenta in Friesian mares and a decrease in fertility and fecundity of the Hucul horse. Larger populations may be affected by inbreeding as well.
Inbreeding in the Thoroughbred horse has increased during the past ten years, which may explain a shorter and more intense racing season. It is more profitable to have a high turnover of horses instead of focusing on sustainable breeding individuals. Studies of the Norwegian trotter have shown that inbreeding has an effect on early abortions. Studies of Standardbred trotters and Finnhorses in Finland show that a higher inbreeding coefficient is significantly correlated with a lower foaling rate. A high inbreeding coefficient results in a reduced semen quality in Shetland pony stallions. A major challenge today is to get a high genetic gain in breeding and still avoid inbreeding caused by too few selected breeding animals. |
| format | First cycle, G2E |
| id | RepoSLU4310 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish swe |
| publishDate | 2012 |
| publishDateSort | 2012 |
| record_format | eprints |
| spelling | RepoSLU43102012-06-15T13:23:50Z https://stud.epsilon.slu.se/4310/ Hur påverkar inavel fruktsamheten hos häst? Selinus, Hanna Animal genetics and breeding Inbreeding has become a problem in some horse breeds. Studies show that it may lead to inbreeding depression which affects e.g. reproduction traits. In the wild there are mechanisms that make horses avoid mating with close relatives. When selection is done by humans this mechanism is removed and intensive breeding for a few traits, for example good racing results, can become a problem. A small population may have more difficulties to maintain a large genetic diversity, for example the Friesian horse and the Hucul horse. The Friesian population has decreased substantially in number over the past hundred years and the population of the Hucul horse is small and closed. This has resulted in an increased rate of retained placenta in Friesian mares and a decrease in fertility and fecundity of the Hucul horse. Larger populations may be affected by inbreeding as well. Inbreeding in the Thoroughbred horse has increased during the past ten years, which may explain a shorter and more intense racing season. It is more profitable to have a high turnover of horses instead of focusing on sustainable breeding individuals. Studies of the Norwegian trotter have shown that inbreeding has an effect on early abortions. Studies of Standardbred trotters and Finnhorses in Finland show that a higher inbreeding coefficient is significantly correlated with a lower foaling rate. A high inbreeding coefficient results in a reduced semen quality in Shetland pony stallions. A major challenge today is to get a high genetic gain in breeding and still avoid inbreeding caused by too few selected breeding animals. Inavel har hos vissa hästraser blivit ett problem. Det kan leda till inavelsdepression och påverka bl.a. reproduktionsförmågan. I naturlig miljö finns mekanismer som gör att hästar undviker att para sig med nära släktingar. När selektion sker genom människor tas denna mekanism bort och intensiv avel för ett fåtal egenskaper, exempelvis bra tävlingsresultat, kan bli ett problem. En population som är liten kan ha större problem att ha kvar en stor genetisk mångfald. Detta gäller frieserhästen och huculponnyn. Frieserhästen har minskat kraftigt i antal under 1900-talet och huculponnyns population är liten och sluten. Det har resulterat i en ökad frekvens av kvarbliven placenta hos frieserhästen och en minskning i fertilitet och fruktsamhet hos huculponnyn. Även större populationer påverkas av inavel. Fullblodet har haft en snabb inavelsökning de senaste tio åren, vilket kan vara en förklaring till att deras tävlingskarriär har blivit kortare och mer intensiv. Det är mer lönsamt att ha en hög omsättning på hästar istället för att inrikta aveln på hållbara individer. Hos den norska travaren har forskning visat att inavelsgraden påverkar om stona kastar (aborterar) under dräktigheten. Studier på de finska varm- och kallbloden har visat att en högre inavelsgrad är signifikant korrelerad med en lägre fölningsprocent. En hög inavelsgrad har också visat sig ge en sämre kvalitet på spermier hos Shetlandsponnyer. En stor utmaning är att få snabba avelsframsteg utan att selektera så få eller nära besläktade individer att inavel kan bli ett problem. 2012-06-15 First cycle, G2E NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/4310/1/selinus_h_120615.pdf Selinus, Hanna, 2012. Hur påverkar inavel fruktsamheten hos häst?. First cycle, G2E. Uppsala: (VH) > Dept. of Animal Breeding and Genetics (until 231231) <https://stud.epsilon.slu.se/view/divisions/OID-670.html> urn:nbn:se:slu:epsilon-s-1224 swe |
| spellingShingle | Animal genetics and breeding Selinus, Hanna Hur påverkar inavel fruktsamheten hos häst? |
| title | Hur påverkar inavel fruktsamheten hos häst? |
| title_full | Hur påverkar inavel fruktsamheten hos häst? |
| title_fullStr | Hur påverkar inavel fruktsamheten hos häst? |
| title_full_unstemmed | Hur påverkar inavel fruktsamheten hos häst? |
| title_short | Hur påverkar inavel fruktsamheten hos häst? |
| title_sort | hur påverkar inavel fruktsamheten hos häst? |
| topic | Animal genetics and breeding |
| url | https://stud.epsilon.slu.se/4310/ https://stud.epsilon.slu.se/4310/ |