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dc.contributor.authorBerry, Donagh*
dc.contributor.authorBuckley, Frank*
dc.contributor.authorDillon, Pat*
dc.contributor.authorVeerkamp, Roel F.*
dc.date.accessioned2017-07-19T14:36:08Z
dc.date.available2017-07-19T14:36:08Z
dc.date.issued2005-11-01
dc.identifier.citationBerry, D.P., Buckely, F., Dillon, P., Veerkamp, R.F. Dairy cattle breeding objectives combining production and non-production traits for pasture based systems in Ireland, End of Project Reports, Teagasc, 2005.en_GB
dc.identifier.urihttp://hdl.handle.net/11019/1178
dc.descriptionEnd of Project Reporten_GB
dc.description.abstractThe objectives of this study were: 1) to estimate genetic (co) variances among body condition score, body weight, milk production, linear type traits and fertility, and 2) to investigate the presence of genotype by environment interactions for milk production, body condition score, and body weight, in Irish grass based seasonal calving herds. Genetic parameters were estimated from a potential 8928 primiparous and multiparous Holstein-Friesian cows over two years (1999 and 2000). Heritability estimates for body condition score (BCS) and body weight (BW) were found to be moderate to high; estimates ranged from 0.27 to 0.51 for BCS, and from 0.39 to 0.61 for BW. Heritability estimates for BCS change and BW change at different stages of lactation were all less than 0.11. Heritability for the linear type traits varied from 0.11 to 0.43. Phenotypic and genetic correlations between BCS and BW at the same stage of lactation were all close to 0.50 indicating that approximately 25% of the genetic and phenotypic variation in BW may be attributed to differences in BCS. Genetic correlations between BCS and milk yield tended to be negative (-0.14 to –0.51) and genetic correlations between BW and milk yield were close to zero (-0.07 to 0.09). However, the genetic correlations between BW adjusted for differences in BCS were positive (0.15 to 0.39). Genetic correlations between BCS and the fertility traits investigated were all favourable, indicating that cows with a superior genetic merit for BCS are on average likely to be served sooner, receive less services and have higher pregnancy rates. The genetic correlations between linear type traits and milk yield indicate that selection for milk production has resulted in taller, deeper cows that tend to be more angular and have less body condition. Genetically these cows are predisposed to inferior reproductive efficiency. Moderate genetic correlations were found between some of the linear type traits investigated and somatic cell count. A comparison of BCS, as recorded by Teagasc personnel (scale 1-5) and Holstein herd-book classifiers (scale 1-9) indicated consistency between the two sources. Phenotypic and genetic correlations of 0.54 and 0.86, respectively, were observed between the two measurement sources on the same animals. Genotype by environment interactions, were found for milk yield across different silage quality environments, and for BCS across different herd-year milk yield, concentrate, grazing severity and silage quality environments.en_GB
dc.language.isoenen_GB
dc.publisherTeagascen_GB
dc.relation.ispartofseriesEnd of Project Reports;
dc.subjectHolstein-Friesian cowsen_GB
dc.subjectGenetic paramentersen_GB
dc.subjectHeritabilityen_GB
dc.subjectBody Condition Scoreen_GB
dc.subjectBody weighten_GB
dc.subjectMilk productionen_GB
dc.subjectLinear type traitsen_GB
dc.subjectFertilityen_GB
dc.subjectGenotypeen_GB
dc.titleDairy cattle breeding objectives combining production and non-production traits for pasture based systems in Ireland.en_GB
dc.typeTechnical Reporten_GB
dc.identifier.rmis5066


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