Bringing the picture up to date, the 2006 to 2008 period shows that the milk yields of those earlier calving heifers has improved still further (chart 5), with a very consistent peak now stretching from 25 to 34 months old. The peak of calvings (chart 6) has now shifted slightly to 25-27 months, while the proportion of animals calving at that peak has also fallen back to 28% of the total, as more herd owners move back slightly from the earlier goal of achieving 100% calving at or around two years.
