Genetic parameters for somatic cell score in the first three lactations of Czech Holstein and Fleckvieh breeds using a random regression model
A multiple-lactation random regression model was applied to test-day somatic cell score (SCS) records from the first three lactations of Czech Holstein and Fleckvieh cows. For Holstein, the data included 26 314 cows, with 244 953, 76 188 and 26 153 test-day records in the first, second and third lac...
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| Format: | Article |
| Language: | English |
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Czech Academy of Agricultural Sciences
2011-06-01
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| Series: | Czech Journal of Animal Science |
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| Online Access: | https://cjas.agriculturejournals.cz/artkey/cjs-201106-0001_genetic-parameters-for-somatic-cell-score-in-the-first-three-lactations-of-czech-holstein-and-fleckvieh-breeds.php |
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| author | L. Zavadilová J. Wolf M. Štípková E. Němcová J. Jamrozik |
| author_facet | L. Zavadilová J. Wolf M. Štípková E. Němcová J. Jamrozik |
| author_sort | L. Zavadilová |
| collection | DOAJ |
| description | A multiple-lactation random regression model was applied to test-day somatic cell score (SCS) records from the first three lactations of Czech Holstein and Fleckvieh cows. For Holstein, the data included 26 314 cows, with 244 953, 76 188 and 26 153 test-day records in the first, second and third lactation, respectively. For Fleckvieh, the data included 24 061 cows, with 223 421, 93 358 and 31 305 test-day records in the first, second and third lactation, respectively. The linear model for SCS included the following factors (for the given parity): fixed herd-test date effect, fixed regressions on days in milk within the age-season class, random regressions for the animal genetic and random regressions for the permanent environmental effect of the cow. Third-degree Legendre polynomials were used for all regressions. Gibbs sampling was used to generate samples from the marginal posterior distributions of the model parameters. The resulting daily heritability ranged from 0.08 to 0.11 in the middle part of lactation and it increased only slightly with parity. Extremely high values (0.25, 0.21) observed especially at the beginning and end of the third lactation for Holstein might be caused by the "end-of-range" problem. The average daily heritabilities computed for the part of lactation between 45 and 255 days in milk (DIM) were in the range from 0.10 to 0.14. Daily permanent environmental variances were higher than the genetic variances and daily residual variances decreased with DIM. The residual variances in early lactation increased with lactation number. For both breeds, the highest genetic correlations computed for the part of lactation between DIM 45 and DIM 255 were obtained between the second and third lactation (0.95). The lowest daily genetic correlations of SCS in the same DIM between different lactations occurred at the beginning of lactation, especially between the first and third lactation. The permanent environmental correlations for selected DIM were lower than the respective genetic correlations. |
| first_indexed | 2024-04-10T08:27:02Z |
| format | Article |
| id | doaj.art-360321d2317248c880ec33362894ed36 |
| institution | Directory Open Access Journal |
| issn | 1212-1819 1805-9309 |
| language | English |
| last_indexed | 2024-04-10T08:27:02Z |
| publishDate | 2011-06-01 |
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| series | Czech Journal of Animal Science |
| spelling | doaj.art-360321d2317248c880ec33362894ed362023-02-23T03:32:53ZengCzech Academy of Agricultural SciencesCzech Journal of Animal Science1212-18191805-93092011-06-0156625126010.17221/1286-CJAScjs-201106-0001Genetic parameters for somatic cell score in the first three lactations of Czech Holstein and Fleckvieh breeds using a random regression modelL. Zavadilová0J. Wolf1M. Štípková2E. Němcová3J. Jamrozik4Institute of Animal Science, Prague-Uhříněves, Czech RepublicInstitute of Animal Science, Prague-Uhříněves, Czech RepublicInstitute of Animal Science, Prague-Uhříněves, Czech RepublicInstitute of Animal Science, Prague-Uhříněves, Czech RepublicCentre for Genetic Improvement of Livestock, Department of Animal and Poultry Science, University of Guelph, Guelph, CanadaA multiple-lactation random regression model was applied to test-day somatic cell score (SCS) records from the first three lactations of Czech Holstein and Fleckvieh cows. For Holstein, the data included 26 314 cows, with 244 953, 76 188 and 26 153 test-day records in the first, second and third lactation, respectively. For Fleckvieh, the data included 24 061 cows, with 223 421, 93 358 and 31 305 test-day records in the first, second and third lactation, respectively. The linear model for SCS included the following factors (for the given parity): fixed herd-test date effect, fixed regressions on days in milk within the age-season class, random regressions for the animal genetic and random regressions for the permanent environmental effect of the cow. Third-degree Legendre polynomials were used for all regressions. Gibbs sampling was used to generate samples from the marginal posterior distributions of the model parameters. The resulting daily heritability ranged from 0.08 to 0.11 in the middle part of lactation and it increased only slightly with parity. Extremely high values (0.25, 0.21) observed especially at the beginning and end of the third lactation for Holstein might be caused by the "end-of-range" problem. The average daily heritabilities computed for the part of lactation between 45 and 255 days in milk (DIM) were in the range from 0.10 to 0.14. Daily permanent environmental variances were higher than the genetic variances and daily residual variances decreased with DIM. The residual variances in early lactation increased with lactation number. For both breeds, the highest genetic correlations computed for the part of lactation between DIM 45 and DIM 255 were obtained between the second and third lactation (0.95). The lowest daily genetic correlations of SCS in the same DIM between different lactations occurred at the beginning of lactation, especially between the first and third lactation. The permanent environmental correlations for selected DIM were lower than the respective genetic correlations.https://cjas.agriculturejournals.cz/artkey/cjs-201106-0001_genetic-parameters-for-somatic-cell-score-in-the-first-three-lactations-of-czech-holstein-and-fleckvieh-breeds.phptest-day somatic cell scorerandom regression modelgenetic parametersholstein cattleczech fleckvieh |
| spellingShingle | L. Zavadilová J. Wolf M. Štípková E. Němcová J. Jamrozik Genetic parameters for somatic cell score in the first three lactations of Czech Holstein and Fleckvieh breeds using a random regression model Czech Journal of Animal Science test-day somatic cell score random regression model genetic parameters holstein cattle czech fleckvieh |
| title | Genetic parameters for somatic cell score in the first three lactations of Czech Holstein and Fleckvieh breeds using a random regression model |
| title_full | Genetic parameters for somatic cell score in the first three lactations of Czech Holstein and Fleckvieh breeds using a random regression model |
| title_fullStr | Genetic parameters for somatic cell score in the first three lactations of Czech Holstein and Fleckvieh breeds using a random regression model |
| title_full_unstemmed | Genetic parameters for somatic cell score in the first three lactations of Czech Holstein and Fleckvieh breeds using a random regression model |
| title_short | Genetic parameters for somatic cell score in the first three lactations of Czech Holstein and Fleckvieh breeds using a random regression model |
| title_sort | genetic parameters for somatic cell score in the first three lactations of czech holstein and fleckvieh breeds using a random regression model |
| topic | test-day somatic cell score random regression model genetic parameters holstein cattle czech fleckvieh |
| url | https://cjas.agriculturejournals.cz/artkey/cjs-201106-0001_genetic-parameters-for-somatic-cell-score-in-the-first-three-lactations-of-czech-holstein-and-fleckvieh-breeds.php |
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