Interactions of Energy Levels Offered to Holstein Cows Prepartum and Postpartum. I. Production Responses and Blood Composition Changes

Abstract

Digestible energy levels of 115% (lowprepartum) and 160% (high-prepartum) of maintenance requirements were provided for groups of 32 Holstein cows during the last six to eight weeks of gestation. All 64 cows were factorially assigned to two energy levels postpartum. One group was fed concentrates sufficient to maintain body weight through a complete lactation (high-postpartum). The second group was fed according, to the energy requirements of lactation recommended by the National Research Council in 1958 (low-postpartum).