animal identification that includes pedigree in formation, routine recording of performance traits, widespread use of AI,and development of state-of-the-art statistical models and evaluation systems has led to rapid genetic gains in traits of economic importance for dairy cattle during the past 100 years. the resulting improvement in production efficiency allows dairy products to be produced with fewer cattle, thereby reducing adverse environmental impacts and conserving natural resources. Increased genetic merit of dairy populations has resulted in a global marketplace for germplasm and live animals.