Use of Mate Selection Software to Manage Lethal Recessive Conditions in Livestock Populations

Abstract Text: Lethal loci with low and intermediate recessive allele frequencies were simulated into a real beef cattle population. The impact of selecting against the number of lethal alleles and recessive lethal genotypes in progeny of available selection candidates were examined in terms of compromised genetic gain relative to selection in the absence of lethal loci considerations. Six lethal loci could be managed with relatively little impact on genetic gain, especially at low allele frequencies; however with 100 lethal loci, decreasing both carrier and homozygous lethal progeny resulted in considerable compromise in genetic gain. Mate selection against homozygous progeny resulted in a superior outcome in terms of genetic gain and reduction in progeny lost as compared to selecting against carrier progeny. As the number of known lethal loci increases, selection strategies will need to optimize balance between compromises in genetic gain and reduced embryo mortality.

Keywords:

recessive

mate selection

lethal