| 11. |
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| 12. |
- Bengtsson, Christian, et al.
(författare)
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Association of genomically enhanced and parent average breeding values with cow performance in Nordic dairy cattle
- 2020
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 103, s. 6383-6391
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Tidskriftsartikel (refereegranskat)abstract
- This study compared the abilities of virgin heifer genomically enhanced breeding values (GEBV) and parent average breeding values (PA) to predict future cow performance. To increase confidence in genomic technology among farmers, a clear demonstration of the relationship between genomic predictions and future phenotypes is needed. We analyzed 12 different traits in first parity, including production, conformation, fer-tility, and other functional traits. Phenotype data were obtained from national milk recording schemes and breeding values from the Nordic Cattle Genetic Evalu-ation. Direct genomic breeding values were calculated using genomic BLUP and combined with traditional breeding values, using bivariate blending. The data covered 14,862 Red Dairy Cattle, 17,145 Holstein, and 7,330 Jersey genotyped virgin heifers born between 2013 and 2015 in Denmark, Finland, and Sweden. Phe-notypes adjusted for systematic environmental effects were used as measures of cow performance. Two meth-ods were used to compared virgin heifer GEBV and PA regarding their ability to predict future cow per-formance: (1) correlations between breeding values and adjusted phenotypes, (2) ranking cows into 4 quartiles for their virgin heifer GEBV or PA, and calculating actual cow performance for each quartile. We showed that virgin heifer GEBV predicted cow performance significantly better than PA for the vast majority of analyzed traits. The correlations with adjusted pheno-types were 38 to 136% higher for GEBV than for PA in Red Dairy Cattle, 42 to 194% higher for GEBV in Holstein, and 11 to 78% higher for GEBV in Jersey. The relative change between GEBV bottom and top quartiles compared with that between PA bottom and top quartiles ranged from 9 to 261% for RDC, 42 to 138% for Holstein, and 4 to 90% for Jersey. Hence, farmers in Denmark, Finland, and Sweden can have confidence in using genomic technology on their herds.
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| 13. |
- Bengtsson, Christian, et al.
(författare)
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Mating allocations in Holstein combining genomic information and linear programming optimization at the herd level
- 2023
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Ingår i: Journal of Dairy Science. - 0022-0302 .- 1525-3198. ; 106, s. 3359-3375
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we explored mating allocation in Hol-stein using genomic information for 24,333 Holstein fe-males born in Denmark, Finland, and Sweden. We used 2 data sets of bulls: the top 50 genotyped bulls and the top 25 polled genotyped bulls on the Nordic total merit scale. We used linear programming to optimize economic scores within each herd, considering genetic level, genetic relationship, semen cost, the economic impact of genetic defects, polledness, and 0-casein. We found that it was possible to reduce genetic relation-ships and eliminate expression of genetic defects with minimal effect on the genetic level in total merit index. Compared with maximizing only Nordic total merit in-dex, the relative frequency of polled offspring increased from 13.5 to 22.5%, and that of offspring homozygous for 0-casein (A2A2) from 66.7 to 75.0% in one genera-tion, without any substantial negative impact on other comparison criteria. Using only semen from polled bulls, which might become necessary if dehorning is banned, considerably reduced the genetic level. We also found that animals carrying the polled allele were less likely to be homozygous for 0-casein (A2A2) and more likely to be carriers of the genetic defect HH1. Hence, adding economic value to a monogenic trait in the economic score used for mating allocation sometimes negatively affected another monogenetic trait. We rec-ommend that the comparison criteria used in this study be monitored in a modern genomic mating program.
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| 14. |
- Bengtsson, Christian, et al.
(författare)
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Mating allocations in Nordic Red Dairy Cattle using genomic information
- 2022
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Konferensbidrag (refereegranskat)abstract
- In this study, we compared mating allocations in Nordic Red Dairy Cattle using genomic or pedigree information. We used linear programming to optimise different economic scores within each herd, considering genetic level, semen cost, the economic impact of recessive genetic defects, and genetic relationships. We found high correlations (≥0.83) between the pedigree and genomic relationship measures. The mating results showed that it was possible to reduce the different genetic relationships between parents with minimal effect on genetic level. Including the cost of known recessive genetic defects eliminated expression of genetic defects. It was possible to reduce genomic relationships between parents with pedigree information, but it was best done with genomic measures. Linear programming maximised the economic score for all herds studied within seconds, which means that it is suitable for implementation in mating software to be used by advisors and farmers.
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| 15. |
- Bengtsson, Christian, et al.
(författare)
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Mating allocations in Nordic Red Dairy Cattle using genomic information
- 2022
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 105, s. 1281-1297
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we compared mating allocations in Nordic Red Dairy Cattle using genomic information. We used linear programming to optimize different economic scores within each herd, considering genetic level, semen cost, the economic impact of recessive genetic defects, and genetic relationships. We selected 9,841 genotyped females born in Denmark, Finland, or Sweden in 2019 for mating allocations. We used 2 different pedigree relationship coefficients, the first tracing the pedigree 3 generations back from the parents of the potential mating and the second based on all available pedigree information. We used 3 different genomic relationship coefficients, 1 SNP-by-SNP genomic relationship and 2 based on shared genomic segments. We found high correlations (≥0.83) between the pedigree and genomic relationship measures. The mating results showed that it was possible to reduce the different genetic relationships between parents with minimal effect on genetic level. Including the cost of known recessive genetic defects eliminated expression of genetic defects. It was possible to reduce genomic relationships between parents with pedigree measures, but it was best done with genomic measures. Linear programming maximized the economic score for all herds studied within seconds, which means that it is suitable for implementation in mating software to be used by advisors and farmers.
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| 16. |
- Berglund, Britt, et al.
(författare)
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Estimating genetic parameters for fertility in dairy cows from in-line milk progesterone profiles
- 2015
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 98, s. 5763-5773
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to define endocrine fertility traits from in-line milk progesterone (P4) records and to estimate genetic parameters for these traits. Correlations of classical fertility (calving interval and calving to first service) and milk production traits with endocrine fertility traits were also estimated. In-line milk P4 records (n = 160,952) collected from June 2009 through November 2013 for 2,273 lactations of 1,561 Holstein-Friesian cows in 12 commercial herds in the Netherlands were analyzed for (the log of) the number of days from calving till commencement of luteal activity (1nC-LA), proportion of samples between 25 and 60 d in milk with luteal activity (PLA), presence or absence of luteal activity for a cow between 25 and 60 d in milk, interval from commencement of luteal activity to first service (CLAFS), first luteal phase length, length of first interluteal interval, and length of first interovulatory interval. Milk P4 records were sampled, on average, every 2 d. Genetic parameters were estimated using a mixed linear animal model. Heritability estimates ( SE) of endocrine fertility traits were 0.12 +/- 0.05 for 1nC-LA, 0.12 0.05 for PLA, and 0.11 +/- 0.06 for CLAFS, and their repeatability estimates were 0.29 +/- 0.04, 0.21 +/- 0.04, and 0.15 +/- 0.06, respectively. The genetic correlation of 1nC-LA with PLA was 0.91 +/- 0.06 and with CLAFS was 0.56 +/- 0.25. The genetic correlations of 1nC-LA were 0.26 +/- 0.33 with calving interval and 0.37 +/- 0.21 with calving to first service. Genetic correlations of the milk production traits with 1nC-LA ranged from 0.04 to 0.18 and 0.07 to 0.65 with classical fertility traits. The phenotypic correlations of all endocrine fertility traits with milk production traits were close to zero (0.01 to 0.07). This study shows that in-line P4 records can be used to define and explore several heritable endocrine fertility traits in dairy cows and might help in selection for improved fertility.
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| 17. |
- Berglund, Britt, et al.
(författare)
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Genetic Parameters for Endocrine Fertility Traits from In-line Milk Progesterone Records in Dairy Cows
- 2014
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Annan publikation (refereegranskat)abstract
- In-line milk progesterone records (n = 163,145) collected from June 2009 through November 2013 for 2,274 lactations of Holstein-Friesian cows in 12 commercial herds in the Netherlands were analyzed for commencement of luteal activity (CLA), luteal activity during first 60 days in milk (LA60), proportion of samples with luteal activity (PLA), interval from commencement of luteal activity to first service, length of first luteal phase, and number of inter-ovulatory intervals before first service. Heritability (0.13, 0.10, and 0.05) and repeatability estimates (0.26, 0.21, and 0.16) were greatest for CLA, PLA and LA60, respectively, compared with other traits. Genetic correlations were 0.96 to 0.99 between these traits. This study shows that in-line P4 records can be used to define and explore several heritable endocrine fertility traits that can be used in genetic improvement of fertility by selection.
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| 18. |
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| 19. |
- Berglund, Paulina, et al.
(författare)
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Should performance at different race lengths be treated as genetically distinct traits in Coldblooded trotters?
- 2024
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Ingår i: Journal of Animal Breeding and Genetics. - 0931-2668 .- 1439-0388. ; 141, s. 220-234
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Tidskriftsartikel (refereegranskat)abstract
- Speed, in the form of racing time per kilometre (km), is a performance trait of the Swedish-Norwegian Coldblooded trotter included in the joint Swedish-Norwegian genetic evaluation. A few popular stallions have dominated Coldblooded trotter breeding, which has led to an increasing average relationship between individuals in the population. This study investigated the scope for broadening the breeding goal by selecting for racing time per km over different race lengths (short: 1640 m, medium: 2140 m and long: 2640 m), as this could encourage the use of breeding sires that are less related to the population. Performance data on three- to 12-year-old Coldblooded trotters in all Swedish races run 1995-2021 were obtained from the Swedish Trotting Association. These data consisted of 46,356 observations for 8375 horses in short-distance races, 430,512 observations for 11,193 horses in medium-distance races and 11,006 observations for 3341 horses in long-distance races. Variance components and genetic correlations were calculated using a trivariate animal model with Gibbs sampling from the BLUPF90 suite of programs. Breeding values for the three traits were then estimated using univariate animal models with the same fixed and random effects as in the trivariate model. Heritability estimates of 0.27-0.28 and genetic correlations between racing time per km at the different distances of 0.97-0.99 were obtained. Despite the strong genetic correlation between the traits, there was some re-ranking among the top 10 and top 30 stallions based on distance-specific breeding values. Estimated rank correlation between breeding values for racing time per km in short- and medium-distance races was 0.86, while between short- and long-distance races and between medium- and long-distance races it was 0.61. Mean relationship within the top 10 and top 30 stallions based on breeding values for racing time per km at each distance was 0.31-0.33 and 0.23-0.24 while mean relationship to the rest of the population ranged from 0.17 to 0.18 for all groups, although the 10 and 30 top-ranking stallions differed somewhat in the traits. Estimated average increase in inbreeding was 0.1% per year of birth and 1.2% per generation. The strong genetic correlation between racing time per km at different distances did not support their use as genetically distinct traits. Re-ranking of stallions for racing time per km at different race lengths could favour the use of a larger number of stallions in breeding, but according to our results it would not promote the use of stallions that are less related to the total population. Other traits like longevity or health traits, for example, career length and orthopaedic status, may be more relevant in broadening the breeding goal and preventing a few sires dominating future breeding, and this would be interesting to study further.
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| 20. |
- Bottani, Gabriela, et al.
(författare)
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Relevance of the production system for the sustainability of conservation and breeding programs for the Creole cattle in Pasorapa, Bolivia
- 2022
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Ingår i: Discover Sustainability. - : Springer Science and Business Media LLC. - 2662-9984. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Local livestock breeds play an important role in the food security of smallholders in developing countries in the Global South. They are also a reservoir of potentially valuable genes for adaptation of global animal genetic resources. The Creole cattle population from Pasorapa, Bolivia, is threatened by effects of climate change and unplanned crossbreeding. The aim of this study was to assess the current situation in this population and to evaluate factors to be considered before implementing conservation and genetic improvement programs in order to achieve the sustainable development goals 1, 2, 13 and 15, which refer to no poverty, zero hunger, climate change and life on land, respectively. We examined and analyzed the most important elements related to the production system and farmers' perceptions that could affect the design of such programs. Open-ended and closed-ended questionnaires and interviews were performed with 81 smallholders from 11 communities in Pasorapa. A rearing system based on two stages and animals feeding mainly on native plants during both, involves a strong interaction between the environment and the production system. A survey of farmers' perceptions about diseases, mortality causes, and selection criteria revealed that farmers in Pasorapa consider coat color an important trait when selecting breeding and replacement animals. Half of all interviewees perceived an association between coat color and traits such as temperament, milk yield, and beef production. In a SWOT analysis we discussed the vulnerability of the system to climate change impacts and the contribution of this traditional system to rural mitigation. Overall, this work revealed the importance of this local ecotype and identified key factors to consider when developing breeding and conservation programs.
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