Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest
More than 1000 Swedish Warmblood foals are shown every year at foal inspections which are arranged around the country. Six traits are evaluated at these inspections: type, head-neck-body, correctness of legs, walk, trot and canter. No previous genetic studies have been done on the data from these ev...
| Autor principal: | |
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| Formato: | L3 |
| Lenguaje: | sueco Inglés |
| Publicado: |
SLU/Dept. of Animal Breeding and Genetics (until 231231)
2008
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| Materias: |
| _version_ | 1855571819449286656 |
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| author | Edlén, Maria |
| author_browse | Edlén, Maria |
| author_facet | Edlén, Maria |
| author_sort | Edlén, Maria |
| collection | Epsilon Archive for Student Projects |
| description | More than 1000 Swedish Warmblood foals are shown every year at foal inspections which are arranged around the country. Six traits are evaluated at these inspections: type, head-neck-body, correctness of legs, walk, trot and canter. No previous genetic studies have been done on the data from these evaluations. The purpose of this study was to do genetic analyses of the traits which are evaluated at foal inspections. The purpose was also to see if there are any correlations between the results of the foal inspections and the results from the tests of three-year-old horses. The results from this study are supposed to provide a basis for a proposal of possible changes in the regulations of the foal evaluations.
In the study, results from foal inspections from the years 2002-2006 (4861 horses) and results from tests of three-year-old horses from the years 1999-2007 (8283 horses) were analysed. 1251 horses had results from both occasions. Heritabilities were estimated for traits evaluated at both foal inspections and the tests of three-year-olds. Genetic and phenotypic correlations were estimated between traits evaluated at foal inspections, between those traits that were evaluated at both evaluations and between the traits from the foal inspections and the free jumping traits from the tests of the three-year-old horses. A comparison was done between breeding values estimated from the total scores of the foals and the BLUP-index (dressage index and jumping index) for stallions with 15 or more evaluated progenies.
The estimated heritabilities for foals varied from very low for correctness of legs (0.02) to moderate for type, head-neck-body and walk (0.27-0.38) to high for trot, canter, total score and class (0.42-0.77). The heritabilities for the traits from the tests of three-year-old horses were in the same range. Moderate heritabilities were estimated for both the free jumping traits. The genetic correlations between traits evaluated on foals were all highly positive (0.43-0.98). Between those traits that were evaluated both on foals and three-year-old horses, the genetic correlations were high (0.86-1.00). Canter was the trait evaluated on foals that had the strongest correlation with the free jumping traits of the tests of the three-year-old horses (0.31-0.34), whereas the other correlations were around zero. The comparison between the BLUP-index and breeding values for total score as foal showed a positive correlation (0.60) between the breeding value and the dressage index but a negative correlation (-0.31) with the jumping index.
The study showed that the whole scale was not used, neither were all the classes. There were clearly positive correlations between the results of the foals and the results of the three-year-old horses concerning type and gaits, but the correlations with the free jumping scores were practically non-existent. A simplified classification should probably be considered, and it is important to clarify that the foal results should not be taken in such consideration that it leads to a neglect of the breeding of jumping horses. An idea would be to include pedigree-indexes (BLUP) into the evaluations and thereby classify the foals for both dressage and jumping. The foal inspections are anyway valuable because they offer an opportunity to market foals, for counseling the owners and they also contribute to an early handling of the foals. |
| format | L3 |
| id | RepoSLU11164 |
| institution | Swedish University of Agricultural Sciences |
| language | swe Inglés |
| publishDate | 2008 |
| publishDateSort | 2008 |
| publisher | SLU/Dept. of Animal Breeding and Genetics (until 231231) |
| publisherStr | SLU/Dept. of Animal Breeding and Genetics (until 231231) |
| record_format | eprints |
| spelling | RepoSLU111642017-09-27T07:30:12Z Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest Edlén, Maria föl arvbarhet genetisk korrelation fölbesiktning More than 1000 Swedish Warmblood foals are shown every year at foal inspections which are arranged around the country. Six traits are evaluated at these inspections: type, head-neck-body, correctness of legs, walk, trot and canter. No previous genetic studies have been done on the data from these evaluations. The purpose of this study was to do genetic analyses of the traits which are evaluated at foal inspections. The purpose was also to see if there are any correlations between the results of the foal inspections and the results from the tests of three-year-old horses. The results from this study are supposed to provide a basis for a proposal of possible changes in the regulations of the foal evaluations. In the study, results from foal inspections from the years 2002-2006 (4861 horses) and results from tests of three-year-old horses from the years 1999-2007 (8283 horses) were analysed. 1251 horses had results from both occasions. Heritabilities were estimated for traits evaluated at both foal inspections and the tests of three-year-olds. Genetic and phenotypic correlations were estimated between traits evaluated at foal inspections, between those traits that were evaluated at both evaluations and between the traits from the foal inspections and the free jumping traits from the tests of the three-year-old horses. A comparison was done between breeding values estimated from the total scores of the foals and the BLUP-index (dressage index and jumping index) for stallions with 15 or more evaluated progenies. The estimated heritabilities for foals varied from very low for correctness of legs (0.02) to moderate for type, head-neck-body and walk (0.27-0.38) to high for trot, canter, total score and class (0.42-0.77). The heritabilities for the traits from the tests of three-year-old horses were in the same range. Moderate heritabilities were estimated for both the free jumping traits. The genetic correlations between traits evaluated on foals were all highly positive (0.43-0.98). Between those traits that were evaluated both on foals and three-year-old horses, the genetic correlations were high (0.86-1.00). Canter was the trait evaluated on foals that had the strongest correlation with the free jumping traits of the tests of the three-year-old horses (0.31-0.34), whereas the other correlations were around zero. The comparison between the BLUP-index and breeding values for total score as foal showed a positive correlation (0.60) between the breeding value and the dressage index but a negative correlation (-0.31) with the jumping index. The study showed that the whole scale was not used, neither were all the classes. There were clearly positive correlations between the results of the foals and the results of the three-year-old horses concerning type and gaits, but the correlations with the free jumping scores were practically non-existent. A simplified classification should probably be considered, and it is important to clarify that the foal results should not be taken in such consideration that it leads to a neglect of the breeding of jumping horses. An idea would be to include pedigree-indexes (BLUP) into the evaluations and thereby classify the foals for both dressage and jumping. The foal inspections are anyway valuable because they offer an opportunity to market foals, for counseling the owners and they also contribute to an early handling of the foals. Varje år visas drygt 1000 svenska varmblodiga (SWB) föl på någon av de fölbesiktningar som anordnas runt om i landet. Vid fölbesiktningarna bedöms sex egenskaper: typ, huvud-hals-bål, extremiteter, skritt, trav och galopp. Inga tidigare genetiska studier har gjorts på materialet från dessa bedömningar. Syftet med detta arbete var att göra genetiska analyser på de egenskaper som bedöms vid fölbesiktningen. Syftet var också att undersöka om det fanns några samband mellan fölbesiktningsresultaten och resultat från treårstest. Resultatet från denna studie ska kunna ligga till grund för en eventuell förändring av regelverket för fölbesiktningarna. I studien analyserades resultat från fölbesiktningar från åren 2002-2006 (4861 hästar) och resultat från treårstest från åren 1999-2007 (8283 hästar). Av dessa hade 1251 hästar resultat från båda bedömningarna. Arvbarheter skattades för egenskaper bedömda vid fölbesiktning och treårstest. Korrelationer beräknades mellan egenskaper bedömda vid fölbesiktning, mellan de egenskaper som bedömts både vid fölbesiktning och vid treårstest och mellan fölbesiktningens egenskaper och de båda löshoppningsbetygen vid treårstestet. En jämförelse gjordes mellan avelsvärden beräknade på fölens totalpoäng och BLUP-index (dressyrindex och hoppindex) för hingstar med 15 eller fler avkommor. Skattningarna av arvbarheterna för egenskaperna vid fölbesiktning varierade från mycket låga för extremiteter (0,02) till medelhöga för typ, huvud-hals-bål och skritt (0,27-0,38) och höga för trav, galopp, totalpoäng och klass (0,42-0,77). Arvbarheterna för motsvarande egenskaper vid treårstest var på samma nivå. För de båda löshoppningsbetygen skattades medelhöga arvbarheter. De genetiska korrelationerna mellan egenskaperna som bedömdes vid fölbesiktningen var alla starkt positiva (0,43- 0,98). Mellan de egenskaper som bedömts både vid fölbesiktning och treårstest var de genetiska korrelationerna genomgående höga (0,86-1,00). Galoppen var den fölbesiktningsegenskap som var högst korrelerat mot löshoppningsbetygen vid treårstestet (0,31-0,34). I övrigt var korrelationerna noll eller svagt negativa. Jämförelsen mellan BLUP-index och avelsvärden för totalpoäng som föl visade på en positiv korrelation (0,60) mellan avelsvärdet och dressyrindex men en negativ korrelation (-0,31) med hoppindex. Studien visade att skalan inte används fullt ut vid fölbesiktningarna. Inte heller används de klasser som finns. Mellan 80 och 97 % av fölen hade fått betyget 7 eller 8 på varje enskild bedömningspunkt. Det fanns tydligt positiva samband mellan fölresultaten och treårstestresultaten vad gäller typ och gångarter, medan sambanden med hoppresultaten i princip var obefintliga. Det finns därför anledning att avdramatisera fölbesiktningarna ur avelssynpunkt. En enklare klassindelning bör sannolikt övervägas, samtidigt som man måste tydliggöra att man inte får ta sådan hänsyn till fölresultaten att hoppaveln åsidosätts. Eventuellt skulle man kunna väga in ett härstamningsindex från BLUP-analyserna i fölbedömningen. Därigenom skulle även hopphärstammade föl erhålla en intressantare bedömning. Oavsett detta är fölbesiktningarna ändå värdefulla då de är ett utmärkt tillfälle att visa upp föl för försäljning, få rådgivning och för att ge fölen en tidig social träning. SLU/Dept. of Animal Breeding and Genetics (until 231231) 2008 L3 swe eng https://stud.epsilon.slu.se/11164/ |
| spellingShingle | föl arvbarhet genetisk korrelation fölbesiktning Edlén, Maria Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest |
| title | Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest |
| title_full | Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest |
| title_fullStr | Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest |
| title_full_unstemmed | Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest |
| title_short | Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest |
| title_sort | genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest |
| topic | föl arvbarhet genetisk korrelation fölbesiktning |