| 1. |
- Petersson, Karl-Johan, et al.
(författare)
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Two decades of selection for fat content in milk
- 2011
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Ingår i: Book of abstracts of the ... Annual Meeting of the European Federation of Animal Science. ; 17, s. 214-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Bett, Cheruioyt Rawlynce, et al.
(författare)
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Cattle Breeds: Extinction or Quasi-Extant?
- 2013
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Ingår i: Resources. - : MDPI AG. - 2079-9276. ; 2, s. 335-357
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Uniquely selected breeds bred over thousands of years of domestication in a wide range of environments have been declared extinct over the last century. Still more breeds are at risk of becoming extinct and the rate continues to accelerate. Assessing the current status and possible future dynamics of livestock breeds is therefore a critical step in the management of Animal Genetic Resources (AnGR). This study applies a qualitative approach to comprehensively analyze cattle genetic resources in selected countries in order to better understand the risk status of cattle breeds and those that need to be considered extinct and/or quasi-extant. The status of each breed, i.e., not at risk, critical, endangered and extinct, was verified using information available at the Domestic Animal Diversity Information System (DAD-IS) web site, as well as cattle statistics (where available) and a breed survey. In most examples, breeds listed as extinct have played important roles in the development of new breeds, and should not be classified as extinct, unless proven otherwise, given that even breeds existing in vivo are developing. Therefore, a new risk status quasi-extant for this category of cattle breeds is suggested. In addition, based on the findings of this study, the concept of breed needs to be questioned as relates to it being a good measure of genetic diversity. Further investigations of the situation of cattle breeds (and other livestock species) in more countries/continents using similar categories are deemed necessary.
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| 7. |
- Braam, Åsa, et al.
(författare)
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Förord: BLUP-index 2011
- 2012
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Ingår i: Hingstar verksamma inom svensk halvblodsavel. ; , s. 253-254
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 8. |
- Braam, Åsa, et al.
(författare)
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Genetic variation in durability of Swedish Warmblood horses using competition results
- 2011
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 142, s. 181-187
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to investigate the possibilities of using number of years in competition as a measure of durability in the genetic evaluation of Swedish Warmblood horses. Competition results recorded between 1971 and 2008 in the disciplines dressage, show jumping and eventing were used to estimate genetic parameters for number of years in competition. Only male horses not used in breeding born between 1967 and 1991 were included in the study (17,962 horses). The study showed that horses with placings in more than one discipline at an early age had the longest competition career. This result suggests that these horses are talented for sports and possibly also that there is a positive effect of all-round training of young horses on their durability. For estimation of genetic parameters for number of years in competition different linear mixed animal models were compared. Depending on the model and transformation the heritability for total number of years in competition varied between 0.07 and 0.17. The lower values were obtained when adjustments in the model were made for age at first placing in competition. Higher heritabilities were obtained for competition years in show jumping and lower for eventing. Performance traits scored at young horse tests and as points in competition (lifetime and for young horses) showed positive genetic correlations with total number of years in competition. These results indicate that years in competition represent both the durability of the horses and their talents for performance. It is suggested that number of years in competition may be used for genetic evaluation of durability.
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| 9. |
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| 10. |
- Carlström, Caroline, et al.
(författare)
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Feasibility of using automatic milking system data from commercial herds for genetic analysis of milkability
- 2013
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 96, s. 5324-5332
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to investigate how useful data from automatic milking systems used in commercial herds are for genetic analysis of milkability traits. Data were available from 4,968 Swedish Holstein and Swedish Red cows over a span of 5 yr (2004-2009) from 19 herds. The analyzed milkability traits were average flow rate, box time, milking interval, and number of milkings per day. Variance components were estimated for genetic, permanent environmental, and residual effects in first and later (second and third) lactations, and were used for estimation of heritabilities and repeatablilites. The experiences of the data quality and editing procedures showed that almost half of the data and about a quarter of the cows had to be excluded from the analyses due to incomplete or inconsistent information. However, much more data are available than is needed for accurate genetic parameter estimations. For the genetic analysis, a repeatability animal model was used that included the fixed effects of herd, year and season, lactation month, and milk yield. The repeatability coefficients were at a high level: highest for average flow rate, with estimates between 0.8 and 0.9. The estimated heritability coefficients were in the range of 0.37 to 0.48, 0.21 to 0.44, 0.09 to 0.26, and 0.02 to 0.07 for average flow rate, box time, milking interval, and number of milkings, respectively. The results from the present study unraveled large genetic variation in milkability traits. The genetic parameter estimates were well in agreement with previous studies of milkability, which proves the feasibility of using data from automatic milking systems for genetic analysis.
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