Future improvement of milk production; potential for nutritional improvement

Milk production/cow has increased so dramatically in the past 30 yr that some people question the wisdom of attempting to further increase milk production for fear we will shorten the lives of our dairy cows. What is the limit to milk production? At least two cows have produced over 22,000 kg of milk in a single lactation and numerous cows consistently produce 9,000 to 14,000 kg of milk/lactation. Therefore, it is evident that there is room for great progress, but it is not possible to predict the limits to milk production by the cow because we cannot see beyond the horizon to tell us what lies ahead. However, we know that nothing in sight appears to be an obstacle to further progress.