Original scientific paper
Estimation of Breed Composition, Breed Heterosis and Epistatic Loss for Percent of Live Spermatozoa in Admixed Swiss Fleckvieh Bulls
Negar Khayatzadeh
; BOKU, Department of Sustainable Agricultural Systems, Division of Livestock Sciences (NUWI), Gregor-Mendel-Strasse, 1180 Vienna, Austria
Gabor Mèszáros
; BOKU, Department of Sustainable Agricultural Systems, Division of Livestock Sciences (NUWI), Gregor-Mendel-Strasse, 1180 Vienna, Austria
Yuri Tani Utsunomiya
; Departamento de Apoio, Saúde e Produção Animal, Faculdade de Medicina Veterinária de Araçatuba, UNESP – Univ Estadual Paulista, Araçatuba, São Paulo, Brazil
Fritz Schmitz-Hsu
; Swiss Genetics, Meielenfeldweg 12, Postfach 466,3052 Zollikofen, Switzerland
Birgit Gredler
; Qualitas AG, Chamerstrasse 56, Ch-6300, Zug, Switzerland
Urs Schnyder
; Qualitas AG, Chamerstrasse 56, Ch-6300, Zug, Switzerland
Maja Ferenčaković
; Department of Animal Science, Faculty of Agriculture, University of Zagreb, Svetošimunska cesta 25, 10000 Zagreb, Croatia
Ino Curik
; Department of Animal Science, Faculty of Agriculture, University of Zagreb, Svetošimunska cesta 25, 10000 Zagreb, Croatia
Johann Sölkner
; BOKU, Department of Sustainable Agricultural Systems, Division of Livestock Sciences (NUWI), Gregor-Mendel-Strasse, 1180 Vienna, Austria
Abstract
The objective of this study was to estimate non-additive genetic effects of heterosis and epistatic loss on percent of live spermatozoa in admixed Swiss Fleckvieh bulls, a composite of Simmental and Holstein Friesian cattle. Heterosis is the additional gain in productivity or fitness of crossbred progeny over the mid purebred parents mean which arises from intra-locus gene interaction. Epistatic effects generally reduce productivity or fitness due to lack of gene interactions of genes from different breeds, which is called epistatic loss. Bovine SNP chip data of were used to predict locus specific breed origin of alleles along the autosomes of 815 admixed bulls as well as 147 Holstein Friesian and 207 Simmental bulls representing the parental breeds. The breed proportions for admixed bulls based on 32,899 SNP were used to calculate breed heterozygosity and epistatic loss, considering additive by additive effects for 1,000,000 random pairs of loci. The average Holstein Friesian ancestry in admixed bulls was estimated to be 0.82. Results of fitting different linear mixed models showed that including breed heterozygosity and epistatic loss improved the model fitness (ΔAIC > 3). The heterosis effect and epistatic loss were estimated 2.5(±1.39) % and -0.65(±1.68) % of live spermatozoa, respectively. High correlation (0.97) between breed heterozygosity and epistatic loss values indicate strong confounding of these effects in the model, indicating that it is not possible to properly separate these effects.
Keywords
Swiss Fleckvieh; admixture; breed composition; heterosis; epistatic loss; live spermatozoa
Hrčak ID:
191778
URI
Publication date:
18.12.2017.
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