Abstract
Application
Provides insights for top bulls selection for beef production by beef producing farmers and beef industries.
Introduction
Genomic evaluation for different traits of beef cattle improves the accuracy of selection. This study aims to evaluate the genetic progress of survival and reproductive traits of cross-bred beef cattle in UK.
Materials and methods
The traits include interval between first and second parities (CI12), age at first calving (AFC), docility, calf size, calf-vigour, survival traits (calf survival at day 30, 90 and 180), and still birth at zero and 48 hours. A total of 1,539,151 animals were in the pedigree, of which 704,892 and 110,903 animals having phenotypes and genotypes, respectively, were used as starting materials. These data originated from the Beef Efficiency Scheme (BES) operated by Scottish Government from 2016 to 2021 whereby farmers opted in to receive farm payments and genotyped a proportion of their beef herd. The pedigree data was dated back to the 1860s, whereas the phenotype data was after 2012. Quality of the genomic data was evaluated using 90% call rate (at animal and marker level) and 0.5% MAF that resulted in 39,554 SNP markers after filtration for the downstream analysis. Mixed linear animal model in a single-step GBLUP (ssGBLUP) approach was employed to obtain genomic estimated breeding values (GEBVs). Depending on the traits, calving season, calving ease, sex, parity and birth type were fitted as fixed effects, and heterosis and recombination of the animals as covariate effects in the model. The variance components and heritabilities were estimated using ASReml and the GEBVs were estimated using Mix99 packages.
Results
Moderate to high heritability estimates were obtained: 0.05 (Surv30d), 0.07 (Surv90d), 0.08 (Surv180d), 0.11 (docility), 0.33 (calf-vigour), 0.39 (calf size), 0.38 (stillbirth0hr), 0.44 (stillbirth48hrs), 0.41 (AFC) and 0.43 (CI12). The genetic trend, GEBV, was summarised every year starting from 1951 to 2021. Hence, the average change of GEBVs over years were estimated to be 0.001% for Surv30d, -0.003% for surv90, 0.3% for surv180, 0.004% for docility, 0.01% for calf-vigour, 0.1% for calf size, -0.001% for stillbirth0hr, -0.001% for stillbirth48hrs and 3.9% for CI. The highest average change of GEBVs over years was observed for AFC, 1.38 ± 12.19 days improvement per year.
Conclusions
The overall trend of GEBVs over years shows that a remarkable improvement has been achieved in UK crossbred beef herds after the 1990s that could be associated with the implementation of structured breeding programs and better phenotyping afterwards. Emergence of the genomic era has brought the introduction of modern breeding tools in the breeding programs which has created a usable reference population for genomic prediction based on Scottish beef cattle.
Provides insights for top bulls selection for beef production by beef producing farmers and beef industries.
Introduction
Genomic evaluation for different traits of beef cattle improves the accuracy of selection. This study aims to evaluate the genetic progress of survival and reproductive traits of cross-bred beef cattle in UK.
Materials and methods
The traits include interval between first and second parities (CI12), age at first calving (AFC), docility, calf size, calf-vigour, survival traits (calf survival at day 30, 90 and 180), and still birth at zero and 48 hours. A total of 1,539,151 animals were in the pedigree, of which 704,892 and 110,903 animals having phenotypes and genotypes, respectively, were used as starting materials. These data originated from the Beef Efficiency Scheme (BES) operated by Scottish Government from 2016 to 2021 whereby farmers opted in to receive farm payments and genotyped a proportion of their beef herd. The pedigree data was dated back to the 1860s, whereas the phenotype data was after 2012. Quality of the genomic data was evaluated using 90% call rate (at animal and marker level) and 0.5% MAF that resulted in 39,554 SNP markers after filtration for the downstream analysis. Mixed linear animal model in a single-step GBLUP (ssGBLUP) approach was employed to obtain genomic estimated breeding values (GEBVs). Depending on the traits, calving season, calving ease, sex, parity and birth type were fitted as fixed effects, and heterosis and recombination of the animals as covariate effects in the model. The variance components and heritabilities were estimated using ASReml and the GEBVs were estimated using Mix99 packages.
Results
Moderate to high heritability estimates were obtained: 0.05 (Surv30d), 0.07 (Surv90d), 0.08 (Surv180d), 0.11 (docility), 0.33 (calf-vigour), 0.39 (calf size), 0.38 (stillbirth0hr), 0.44 (stillbirth48hrs), 0.41 (AFC) and 0.43 (CI12). The genetic trend, GEBV, was summarised every year starting from 1951 to 2021. Hence, the average change of GEBVs over years were estimated to be 0.001% for Surv30d, -0.003% for surv90, 0.3% for surv180, 0.004% for docility, 0.01% for calf-vigour, 0.1% for calf size, -0.001% for stillbirth0hr, -0.001% for stillbirth48hrs and 3.9% for CI. The highest average change of GEBVs over years was observed for AFC, 1.38 ± 12.19 days improvement per year.
Conclusions
The overall trend of GEBVs over years shows that a remarkable improvement has been achieved in UK crossbred beef herds after the 1990s that could be associated with the implementation of structured breeding programs and better phenotyping afterwards. Emergence of the genomic era has brought the introduction of modern breeding tools in the breeding programs which has created a usable reference population for genomic prediction based on Scottish beef cattle.
| Original language | English |
|---|---|
| Title of host publication | Animal - science proceedings |
| Publisher | Elsevier |
| Chapter | 149 |
| DOIs | |
| Publication status | Print publication - Apr 2023 |