Canola breeding in Australia began in the early 1970s with the first cultivars being released in the late 1970s. Thirty-four non-herbicide-tolerant canola cultivars, released in Australia between 1978 and 2012, were evaluated for improvements in yield, quality, blackleg resistance and adaptation to Australian environments. The cultivars were sown at three sites in 2008 and one site in 2014. In addition, blackleg susceptibility was assessed in two independent blackleg experiments in 2008. Yield improvement averaged 21.8 kg ha–1 year–1 (1.25% year–1) but ranged from 8 to 39.1 kg ha–1 year–1 at the lowest to the highest yielding sites, respectively. Although the yield gain shown by our study was for conventional canola only, the different herbicide-tolerant types are derived by incorporating the herbicide tolerance genes into Australian germplasm and so the rate of genetic gain would be expected to be similar for all herbicide tolerance types. Oil and protein concentrations have increased by 0.09% year–1 and 0.05% year–1, respectively, whereas glucosinolate concentration was reduced to between 7 and 16 μmoles per gram of meal by the mid-1990s. Cultivars released before 2002 all had low to moderate resistance to the blackleg isolates present in the fields during the experimental period but more recent releases had improved survival under heavy blackleg pressure due to the incorporation of additional or different resistance genes. The data suggests that at least 25% of the yield improvement achieved by the breeding programs over 30 years was associated with improved blackleg resistance and the remainder with gains in other aspects of potential grain yield. The private breeding companies in Australia will need to continue to produce cultivars with high yield potential and deploy blackleg resistance genes wisely in order to maintain the yield improvements required to remain competitive in global markets.

Urea supplementation of lambing Merino ewes increased milk yield and lamb growth and survival rates in both pen and paddock studies. These productivity gains occurred in a semi-arid environment characterized by poor reproductive efficiency in Merinos. In pens, urea supplenlents fed to lactating ewes at the rate of c. 12 g/day stimulated intake of poor quality pasture hay (0.9 %nitrogen) by c. 30% and increased total nitrogen intake by c. 100%. Milk yield was improved by c. 50% and lamb growth rate by c. 140%. Sorghum grain supplements stimulated milk yield and lamb growth to a lesser extent than urea. The correlations found in pen studies between nitrogen intake and milk yield of ewes (r � 0.85; P < 0.05), and between ewe milk yield and lamb growth (r % 0.80; P < 0.01), prompted further investigations under paddock conditions. Ewes grazing dry pastures and supplemented with urea (8-10 glday) via drinking water yielded more milk (11-32%) than unsupplemented counterparts. Similarly, there were improvements in lamb growth (80-100%) and survival (c. 10%) in the supplemented groups.