The summaries available in the links to the left provide details about lambing rates, death losses, and lambings per year in the Cornell flock.
Many annual-lambing flocks should have much higher lambs per ewe, depending upon which ewes are counted. Many smaller flocks should also have higher survival rates than those shown here. Lamb mortality in the Cornell flock has been mainly from lamb pneumonia. Death losses in the Cornell flock are similar to published values (see literature summary and the summary in the April 2007 issue of The Shepherd magazine of crossbred survival rates at the US Meat Animal Research Center where lamb losses of lambs from ewes lambed under intensive management ranged from 17 to 30%).
One of the obvious objectives of the Cornell flock is to define management procedures to increase survival rates of lambs in accelerated-lambing flocks. In fall of 2008, we added about 7% water to all of our diets in order to reduce diet dustiness and this appears to have dramatically reduced pnuemonia in older lambs. During 2006 to 2009, we have seen an increasing incidence of abomasal hemorrhage in lambs about 2 to 3 weeks old. This is a common disease in artificially-reared replacement dairy heifers, in which it is controlled by adding antibiotics to the milk replacer. There is no known way to prevent it in lambs and we are working on several possibilities.