NUTRIENT DIGESTION AND NITROGEN RETENTION BY LAMBS FED MILK REPLACERS CONTAINING SOLVENT-EXTRACTED OR FULL-FAT PRODUCTS FROM DIFFERENT RAPESEED CULTIVARS

Abstract

Bronowski, Oro and Tower rapeseed were dehulled, heated, and water- and solvent-extracted to produce a protein concentrate (RPC) or only dehulled, heated and water-extracted to produce a full-fat rapeseed material (FFRS). These materials were added to lamb milk replacers to provide up to 50% of the dietary protein. RPC materials from the three cultivars were highly digestible (89% or more of dry matter) and produced similar values for nitrogen retention (60% of intake) by lambs. The FFRS materials were poorly digested (79% of dry matter or less) and generally decreased lamb performance. When the FFRS was passed through a colloid mill, digestibility values and retention of nitrogen increased to values equivalent to those obtained with RPC. Homogenization of the colloid-milled FFRS did not further improve its nutritive value for preruminant lambs. Thus, low-glucosinolate, low-erucic acid rapeseed which has been dehulled, heated, water-extracted and colloid-milled is a good source of protein and energy for lamb milk replacers.