With the advent of twinning in beef cows there is a need to obtain information on the nutritional requirements of these animals during the last three months of pregnancy and to assess the effects of pre-calving nutrition on cow and calf performance in the subsequent lactation. Three experiments have been carried out With 10, 9 and 14 multiple bearing Hereford x British Friesian cows. In each experiment a comparison was made With single bearing cows but the results from these animals are not considered in this paper. The cows were given different energy intakes in a factorial arrangement with low or high levels of UDP over the last three months of pregnancy. After calving all cows were given 125 MJ ME/d for the first 12 Weeks of lactation and performance monitored to assess any carryover effect of pregnancy nutrition.

Similar diets were fed during the last three months of pregnancy in all three experiments. The diet containing a low level of UDP (0.19 of total protein) consisted of barley straw, barley grain, molassed meal and urea. While that With a high UDP content (0.33 of total protein) contained barley straw, barley grain, malt distillers dark grains and special propietary cubes.