Abstract

BackgroundIn livestock, deleterious recessive alleles can result in reduced economic performance of homozygous individuals in multiple ways, e.g. early embryonic death, death soon after birth, or semi-lethality with incomplete penetrance causing reduced viability. While death is an easy phenotype to score, reduced viability is not as easy to identify. However, it can sometimes be observed as reduced conception rates, longer calving intervals, or lower survival for live born animals.MethodsIn this paper, we searched for haplotypes that carry putatively recessive lethal or semi-lethal alleles in 132,725 genotyped Irish beef cattle from five breeds: Aberdeen Angus, Charolais, Hereford, Limousin, and Simmental. We phased the genotypes in sliding windows along the genome and used five tests to identify haplotypes with absence of or reduced homozygosity. Then, we associated the identified haplotypes with 44,351 insemination records that indicated early embryonic death, and postnatal survival records. Finally, we assessed haplotype pleiotropy by estimating substitution effects on estimates of breeding value for 15 economically important traits in beef production.ResultsWe found support for one haplotype that carries a putatively recessive lethal (chromosome 16 in Simmental) and two haplotypes that carry semi-lethal alleles (chromosome 14 in Aberdeen Angus and chromosome 19 in Charolais), with population frequencies of 8.8, 15.2, and 14.4%, respectively. These three haplotypes showed pleiotropic effects on economically important traits for beef production. Their allele substitution effects are Euro2.30, Euro3.42, and Euro1.47 for the terminal index and Euro1.03, -Euro3.11, and -Euro0.88 for the replacement index, where the standard deviations for the terminal index are Euro22.52, Euro18.65, and Euro22.70 and for the replacement index they are Euro31.35, Euro29.82, and Euro35.79. We identified ZFAT as the candidate gene for semi-lethality in Aberdeen Angus, several candidate genes for the lethal Simmental haplotype, and no candidate genes for the semi-lethal Charolais haplotype.ConclusionsWe analysed genotype, reproduction, survival, and production data to detect haplotypes that carry putatively recessive lethal or semi-lethal alleles in Irish beef cattle and identified one lethal and two semi-lethal haplotypes, which have pleiotropic effects on economically important traits in beef production.

Published in

Genetics Selection Evolution
2019, Volume: 51, article number: 9

SLU Authors

• Johnsson, Martin

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    
  • Linköping University

UKÄ Subject classification

Genetics and Breeding


Publication identifier

DOI: https://doi.org/10.1186/s12711-019-0452-z

Permanent link to this page (URI)

https://res.slu.se/id/publ/98931