Dual-purpose crops: Comparison of maternal systems grazing canola or wheat during late pregnancy and lambing then lucerne-based pasture until weaning

Dual-purpose crops can reduce winter feed gaps and allow an increase in farm stocking rates on mixed farms.This study sought to compare the effect of inclusion of dual-purpose crops on livestock systemsproducing meat only compared with a system producing meat and wool. Six plots (1.86ha) were sown toeither dual-purpose wheat or canola in April 2014 in a replicated design. White Dorper ewes joined to eitherWhite Suffolk (WSD) or White Dorper (Dorper) rams, and Merino ewes joined to White Suffolk (WSM)rams were scanned in lamb on 15 May and allocated to plots on 19 June at a stocking rate of 13 ewes/ha,with a minimum of six ewes of each genotype per plot. Lambing commenced on 13 July and lamb birth weights were recorded. Ewes and lambs grazed lucerne-based pasture from 12 August until weaning on 29 September when all ewes and lambs were weighed. Crude protein levels were initially higher in wheat, but were lower at the conclusion of grazing; digestibility was initially similar between crops but declined in wheat during the grazing period; and NDF was always lower in canola compared to wheat (all P<0.001). Ewe liveweights were significantly (P<0.001) heavier when grazing wheat compared to canola at the end of crop grazing, but there was no significant difference at weaning. The interaction of crop and lamb genotype was significant for lamb weaning weights (P=0.027) with White Dorper lambs from the wheat treatments being significantly lighter than from the canola treatment.