A meta-analysis of the gap between pedigree-based and genomic heritability estimates for production traits in dairy cows

Khanzadeh, H. and Ghavi Hossein-Zadeh, N. and Ghovvati, S.

Livestock Science (2022) 263:

DOI: 10.1016/j.livsci.2022.105000

Abstract

This study aimed to conduct a meta-analysis based on a random-effects model to combine different published pedigree-based and genomic heritability estimates for production traits in dairy cows. Also, the missing heritability estimates for the studied traits were determined. In total, 148 heritability estimates from 62 journal articles were used to conduct this meta-analysis. Heterogeneity among studies was evaluated using the I2 index and Chi-square (Q) test. The estimated pedigree-based and genomic heritabilities were 0.253 and 0.144 for milk yield (MY), 0.290 and 0.191 for milk fat percentage (FP), and 0.378 and 0.363 for milk protein percentage (PP), respectively. The gap between genomic and pedigree-based heritability estimates was high for MY (43%) and medium for FP (34%). Also, the difference between genomic and pedigree-based heritabilities was low for PP (11%). Meta-analysis of pedigree-based heritabilities for all traits indicated significant and high heterogeneity. Also, significant and moderate heterogeneity was observed for the genomic heritability of MY. Publication bias was evaluated for genomic heritability of FP and PP that did not indicate significant heterogeneity. Egger’s test did not show any significant publication bias for the meta-analysis of genomic heritabilities for FP and PP. This study revealed that estimation of genomic heritabilities by appropriate genotyping and statistical methods could improve the accuracy of genetic parameter estimates for production traits in dairy cows. These estimates would be helpful for future breeding programs and the study of the genetic architecture of production traits in dairy cows.

Citation

Khanzadeh, H., Ghavi Hossein-Zadeh, N., & Ghovvati, S. (2022). A meta-analysis of the gap between pedigree-based and genomic heritability estimates for production traits in dairy cows. Livestock Science, 263. https://doi.org/10.1016/j.livsci.2022.105000 cows, dairy cattle, dairy cows, meta-analysis, milk fat, heritability, animal breeding, milk, milk production, milk yield, genome analysis, genomes, milk composition, milk quality, milk fat percentage, milk protein percentage, milk proteins, Genome, genomics, pedigree

Keywords

• cows
• dairy cattle
• dairy cows
• meta-analysis
• milk fat
• heritability
• animal breeding
• milk
• milk production
• milk yield
• genome analysis
• genomes
• milk composition
• milk quality
• milk fat percentage
• milk protein percentage
• milk proteins
• Genome
• genomics
• pedigree