Användning av könssorterad sperma i nötkreatursaveln
Almost for as long as there has been breeding on bovine species, there has been a wish to have a higher proportion of offspring of either one or the other gender. In dairy cattle, heifers are more valuable, while in beef stock bulls are preferred. Semen is sorted based on the difference in DNA conte...
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| Formato: | L3 |
| Lenguaje: | sueco Inglés |
| Publicado: |
SLU/Dept. of Animal Breeding and Genetics (until 231231)
2009
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| Materias: |
| _version_ | 1855571821383909376 |
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| author | Marby, Davida |
| author_browse | Marby, Davida |
| author_facet | Marby, Davida |
| author_sort | Marby, Davida |
| collection | Epsilon Archive for Student Projects |
| description | Almost for as long as there has been breeding on bovine species, there has been a wish to have a higher proportion of offspring of either one or the other gender. In dairy cattle, heifers are more valuable, while in beef stock bulls are preferred. Semen is sorted based on the difference in DNA content between the X- and Y-chromosome in the genome of the sperm. X-chromosomes contain on average between 3,70 to 4,22% more genetic material than the Y-chromosome. Commercially it is the method of flow cytometry that is being used, which is always under improvement. There are differences in fertility between breeds, but there are no differences in precision of sorting between breeds. With unsorted sperm a 55 to 60% conception rate can be achieved on heifers, whereas with sorted sperm the conception rate is between 35 to 40%. In spite of the fears that the sorting process damages DNA and causes abnormal offspring, no reports confirm this. The genetic progress has been estimated to increase with 0,4 to 1,4 percent with sexed semen. To achieve the highest possible economical gain heifers should be used for AI with sexed semen, and not cows, since heifers have higher fertility. It is more expensive to use sorted sperm than conventional semen and the number of sperm in one dose is lower for sorted sperm. Many of the ethical aspects that exist with sorted sperm speak for its usage. These aspects include fewer cases of dystocia, increased bio security and higher biological efficiency. |
| format | L3 |
| id | RepoSLU11173 |
| institution | Swedish University of Agricultural Sciences |
| language | swe Inglés |
| publishDate | 2009 |
| publishDateSort | 2009 |
| publisher | SLU/Dept. of Animal Breeding and Genetics (until 231231) |
| publisherStr | SLU/Dept. of Animal Breeding and Genetics (until 231231) |
| record_format | eprints |
| spelling | RepoSLU111732017-09-26T10:30:13Z Användning av könssorterad sperma i nötkreatursaveln The use of sexed semen in bovine breeding Marby, Davida könssorterad sperma nötkreatur avel Almost for as long as there has been breeding on bovine species, there has been a wish to have a higher proportion of offspring of either one or the other gender. In dairy cattle, heifers are more valuable, while in beef stock bulls are preferred. Semen is sorted based on the difference in DNA content between the X- and Y-chromosome in the genome of the sperm. X-chromosomes contain on average between 3,70 to 4,22% more genetic material than the Y-chromosome. Commercially it is the method of flow cytometry that is being used, which is always under improvement. There are differences in fertility between breeds, but there are no differences in precision of sorting between breeds. With unsorted sperm a 55 to 60% conception rate can be achieved on heifers, whereas with sorted sperm the conception rate is between 35 to 40%. In spite of the fears that the sorting process damages DNA and causes abnormal offspring, no reports confirm this. The genetic progress has been estimated to increase with 0,4 to 1,4 percent with sexed semen. To achieve the highest possible economical gain heifers should be used for AI with sexed semen, and not cows, since heifers have higher fertility. It is more expensive to use sorted sperm than conventional semen and the number of sperm in one dose is lower for sorted sperm. Many of the ethical aspects that exist with sorted sperm speak for its usage. These aspects include fewer cases of dystocia, increased bio security and higher biological efficiency. Nästan lika länge som man avlat på nötkreatur har man velat ha en högre andel av antingen det ena eller det andra könet. I mjölkrasbesättningar är kvigor mycket mer värdefulla emedan hos köttraser tjurar värderas högre. Sperman sorteras baserat på skillnaden i DNA innehåll mellan X- och Y-kromosomen i sperman, där X-kromosomen innehåller mellan 3,70- 4,22% mer genetiskt material beroende på ras. Den metod som har fått störst kommersiell genomslagskraft är flödescytometrin som är en metod under ständig förbättring. Det existerar skillnader i fertilitet hos spermier mellan raser, men ingen skillnad i precision av sorteringen. Med osorterad sperma kan det på kvigor erhållas en konceptionsfrekvens mellan 55 till 60% och en frekvens på 35 till 40% för sorterad. Trots oron att tekniken för sortering av sperma skadar DNA:t, och därmed orsakar defekter på avkomman, har man i litteraturen aldrig funnit belägg för detta. Det genetiska framsteget beräknas öka med mellan 0,4 till 1,4% i och med användningen av sorterad sperma. För högsta ekonomiska vinning bör kvigor insemineras med sorterad sperma och inte inkalvade kor, eftersom kvigor har högre fertilitet. Det är dyrare med sorterad sperma än osorterad och antalet spermier per dos jämfört med konventionell sperma är lägre. Många av de etiska aspekter som existerar med sorterad sperma talar för dess användande. Dessa inkluderar färre fall av kalvningssvårigheter, ökad biologisk säkerhet för besättningar och högre biologisk effektivitet. SLU/Dept. of Animal Breeding and Genetics (until 231231) 2009 L3 swe eng https://stud.epsilon.slu.se/11173/ |
| spellingShingle | könssorterad sperma nötkreatur avel Marby, Davida Användning av könssorterad sperma i nötkreatursaveln |
| title | Användning av könssorterad sperma i nötkreatursaveln |
| title_full | Användning av könssorterad sperma i nötkreatursaveln |
| title_fullStr | Användning av könssorterad sperma i nötkreatursaveln |
| title_full_unstemmed | Användning av könssorterad sperma i nötkreatursaveln |
| title_short | Användning av könssorterad sperma i nötkreatursaveln |
| title_sort | användning av könssorterad sperma i nötkreatursaveln |
| topic | könssorterad sperma nötkreatur avel |