Quantitative trait loci mapping methods and potential applications in the dairy cattle industry.

摘要

All bovine autosomes have been reported to harbour quantitative trait loci (QTL) with effects on milk, fat and protein (kg and percentage), resistance to mastitis and somatic cell score (SCS). The detection of QTL depends on the presence of linkage disequilibrium (LD) between the genetic markers and QTL in the population under study. Because different populations are likely to have different allelic frequencies and amounts of LD, it is possible that markers associated with a particular QTL affecting quantitative traits in a population may not have the marker assisted selection (MASe) association with the MASe QTL in another population. Thus, regardless of the potential success of QTL mapping in other countries, QTL mapping in dairy cattle is an activity that must be undertaken within a country interested in applying MASe. The objective of this review is to present the main results in the detection of QTL in dairy cattle (mainly in Holstein-Friesian) for both yield and mastitis resistance traits, as well as to discuss several factors that may affect QTL mapping. Useful information for the design of QTL mapping programmes in dairy cattle in Mexico is provided..