To increase LDY in Germany, longevity of dairy cows should be improved
Health and longevity of dairy cows are not only important for animal welfare but especially necessary to improve efficiency of dairy production. A parameter of efficiency of milk production should include both milk yield and longevity. Two parameters could be used: Lifetime Daily Yield and Productive Life Daily Yield. Farmers who rear their calves and heifers by themselves should use Lifetime Daily Yield. It includes not only productive time but rearing time too. Farmers without own reproduction should use Productive Life Daily Yield. Lifetime Daily Yield is calcuated by dividing lifetime milk yield by the number of days of life. It can only be calculated after a cow has been culled, but while it is living, it could be a useful parameter to monitor efficiency of each cow and the whole herd. Increasing this parameter is possible by different ways: decrease age of first calving, increase milk yield and prolong productive time.