Protein metabolism of prolific ewes during late gestation and early lactation

<p>Subject headings: protein / metabolism / ewes</p><p>Introduction of prolific crossbred ewes and a new protein evaluation system for ruminants, the DVE/OEB system, necessitate a reconsideration of ewe feeding strategies. The objective of this thesis is to investigate the amount of protein digested in the small intestine (DVE), the efficiency by which the digested protein is used during late pregnancy and early lactation and to evaluate current Dutch protein feeding strategy. This feeding strategy was developed for ewes bearing one or two lambs, but it shows that prolific ewes yield approximately10% more DVE from the same feed. This is due to rumen degradation enhancement resulting in larger amounts of effectively degraded protein and synthesised microbial protein in prolific ewes. Winter shearing results in further increases in DVE yield. Current DVE maintenance requirements and production efficiencies are also valid for prolific ewes. The DVE requirements for prolific ewes, calculated from the measured protein production and efficiency of protein utilisation, are in agreement with the requirements derived from the feeding trials during late pregnancy and early lactation. Adaptation of the current protein feeding strategy is proposed for prolific crossbred ewes.</p>