Extrusion of canola oilcake meal and sweet lupins on the production performance of Meatmaster lambs under feedlot conditions

Abstract

Increasing commodity prices of plant proteins pressure farmers to start exploring alternative methods to optimize utilization of these dietary sources; heat treatment (extrusion) is tested in this study. Canola oilcake meal and sweet lupins were extruded to attempt to increase the amount of rumen undegradable protein. Meatmaster lambs were kept under feedlot conditions and fed four different diets: canola oilcake meal, control (CC); canola oilcake meal, extruded (CE); sweet lupins, control (LC); and sweet lupins, extruded (LE) to determine the effect of extrusion on growth performance. Performance parameters such as average daily gain, feed conversion, and feed intake were compared. A feed conversion ratio of 4.62 vs. 4.85 kg feed/kg weight gain was determined for the extruded diet vs. the control diet (not extruded). An average daily gain of 0.310 and 0.320 kg/day were obtained for the control and extruded diets, respectively. Daily feed intake was similar on the extruded (1.440 kg) and control diets (1.437 kg).The performance parameters of lambs on canola oilcake meal (17.4% inclusion) or sweet lupins (26.6% inclusion) were similar. An average fat level of 4 mm (7–9 mm back fat thickness) was achieved, with no effect of processing or protein source. Sweet lupins were identified as an inexpensive, locally-produced alternative plant protein source to canola oilcake meal, with similar performance parameters obtained in feedlot lambs.