Publications by authors named "Andrzej Zarnecki"
The objective of this study was to estimate genetic parameters for the analyzed fertility traits of Polish Holstein-Friesian primiparous and multiparous cows, as a step toward the incorporation of new traits into routine genetic evaluation. Lactation records of 116,836 Polish Holstein-Friesian cows were studied. The records cover the first three lactations of all cows.
View Article and Find Full Text PDFThe goal of our study was to identify the SNPs, metabolic pathways (KEGG), and gene ontology (GO) terms significantly associated with calving and workability traits in dairy cattle. We analysed direct (DCE) and maternal (MCE) calving ease, direct (DSB) and maternal (MSB) stillbirth, milking speed (MSP), and temperament (TEM) based on a Holstein-Friesian dairy cattle population consisting of 35,203 individuals. The number of animals, depending on the trait, ranged from 22,301 bulls for TEM to 30,603 for DCE.
View Article and Find Full Text PDFLongevity is one of the functional traits that considerably affect dairy herd profitability. A Weibull proportional hazards model was used to evaluate the impact of difficult calvings and calf stillbirths on cow functional longevity, defined as length of productive life corrected for milk production. The data for analysis comprised calving ease and calf mortality scores of 2,163,426 calvings, 34.
View Article and Find Full Text PDFArticle Synopsis
- The study focused on applying a genomic evaluation model to Polish Holstein-Friesian dairy cattle using a training set of 1,227 bulls' SNP data from the Illumina BovineSNP50 chip.
- The model assessed 29 traits, including milk production and fertility, and showed high correlations (up to 0.98) between genomic values and traditional breeding values, indicating strong predictive power.
- The model successfully met interbull validation criteria, suggesting that genomic selection can be effectively implemented in this breed.
Background: Longevity expressed as the number of days between birth and death is a trait of great importance for both human and animal populations. In our analysis we use dairy cattle to demonstrate how the association of Single Nucleotide Polymorphisms (SNPs) located within selected genes with longevity can be modeled. Such an approach can be extended to any genotyped population with time to endpoint information available.
View Article and Find Full Text PDFPractical application of daughter yield deviations in dairy cattle breeding.
J Appl Genet
August 2008
Article Synopsis
- DYDs and EBVs are key metrics for evaluating the genetic quality of dairy cattle, with DYDs including both additive polygenic and residual components, while EBVs focus solely on the additive value.
- A study of the Polish dairy cattle population revealed strong correlations between DYDs and EBVs, although these correlations vary based on the number of daughters used and DYD accuracy.
- The research also highlighted how DYDs can help validate genetic trends and identify significant gene effects, with the leptin receptor gene showing a notable influence on milk yield.