Direct selection for resistance traits in dairy cattle, including the traits of disease resistance, is facilitated by the possibility to determine the variants of the causal genes.
Exploitation of the variants of genes acting in innate immunity complements the calculated breeding values and selection indices in the herd improvement. The method concentrates possibilities provided by TLR genes as the key group of the innate immunity genes for genetic diagnostics. The TLR genes code for a series of ten so-called Toll-like receptors that are associated with a subsequent signalling pathway activating defence response. The method includes those TLR gene variants that are present in the dairy cattle populations of the Czech Republic according on the survey based the next-generation sequencing. Another criterion is a computer prediction of a significant effect of the change on the protein level. The third criterion are the data that were published about the variant effect for the world cattle populations. These data are included in the method description and provide a basis for the exploitation of the test results by breeders. The data about the effects will be completed with the results of the validation of the variant effects in dairy cattle, as based on the already terminated project of the National Agency for Agricultural Research of the CR QJ1610489 and associated research in future. Technically, the method is based on the amplification of the regions of the TLR genes from the samples of cattle genomic DNA and performing genotyping reactions on these fragments. The reactions are of the primer extension type (SNaPshot). In addition to the economic contribution of the method for breeding, it is necessary to take into account the restrictions on the antibiotic use, improvement of the animal welfare, and also the stability of the heard in case of the zoonoses. Breeding for the health traits must be considered as a part of the sustainable agriculture.