USE OF TEST-DAY MILK YIELD FOR GENETIC EVALUATION IN DAIRY CATTLE: A REVIEW

The use of appropriate method for genetic evaluation of dairy animals is an important aspect of dairy cattle production. Traditional 305-day lactation model does not account for the changes in environmental factors within 305-day lactation and may involve unjustified projection of incomplete lactations. The use of test-day model in the recent past has made it possible to economize the genetic evaluation with a better accuracy. This paper reviews the recent developments in genetic evaluation of dairy cattle in the developed production set ups and explores the possibility of using test-day model for genetic evaluation of dairy cattle in Pakistan. Different options within test-model approach are also discussed