Canola and Calves: An Integrated Crop-Livestock Farming System for Producing Canola and Stocker Calves.

Research was conducted to compare and establish appropriate grazing management strategies that optimize stocker calf production and the agronomic performance of canola. Nine 0.66-ha paddocks were blocked by previous tillage history and randomly assigned to 1 of 4 treatments including: Canola lightly grazed to Harper and Berkenkamp (1975) growth stage (GS) 3.0, (CEG), canola grazed to GS 3.1 (CLG), canola-no graze (CNG), and winter wheat grazed until jointing Feekes GS 6, (WW). Additionally, 18 Angus steers (248 ± 19 kg) were blocked by body weight and randomly assigned to 1 of 9 paddocks for grazing. The paddocks were divided into 2 subpaddocks and rotationally stocked utilizing put and take steers to manage crop growth. Leaf area index (LAI), and Near Difference Vegetation Indices (NDVI) were non-destructively assessed using a handheld CropCircle remote sensing device and a LI-COR LAI-2200 Plant Canopy Analyzer for each paddock every 2 wk. At this same time, destructive samples were collected by hand to 2.5 cm stubble in 3 randomly located 0.1 m² areas in each paddock to assess herbage biomass yield. Herbage biomass was measured weekly in all paddocks using a rising plate meter (RPM) at approximately 40 random locations along a randomly located transect. Body weights for stocker calves were measured on d 0 and 49. Data were analyzed using Proc Mixed (SAS v9.4). Experimental unit was paddock and steer was observational unit with steer within paddock by block as the random term. Grazing treatment did not influence (P > 0.05) herbage biomass yield, LAI, ADG, and seed oil content. Grazing treatment did influence (P < 0.05) GS with CLG being the highest and CNG being the lowest. NDVI was influenced (P < 0.05) by treatment with CLG being the greatest and CNG being the least. Seed yield was also influenced (P < 0.05) by treatment with CLG having the least yield, and CEG having the greatest yield. These data show that implementation of appropriate grazing management strategies can optimize stocker calf production and not compromise seed yield and oil content of the canola.