Growth and carcass characteristics of prime lambs fed diets containing urea, lupins or canola meal as a crude protein source

Abstract

Lupin grain typically provides the main source of protein in most lamb finisher diets in Western Australia. The aim of this work was to determine whether alternative sources of nitrogen could provide a less expensive means of achieving the desired rate of liveweight gain and carcass characteristics. Fifty-one crossbred lambs were finished using 3 different sources of crude protein. These sources were either: (i) a control diet consisting of lupins, oats, barley and cereal chaff in which lupins provided 49% of the nitrogen (lupin diet); (ii) a diet consisting of a combination of cereal grain and urea (urea diet); or (iii) a diet in which lupins were partially replaced with expeller canola meal (canola diet). Diets were isonitrogenous (14.4% crude protein) and isoenergetic (10.5 MJ ME/kg DM). Lambs were gradually introduced to the diets over 2 weeks before being fed the diets