Robustness as a breeding goal
In its ‘Sustainable Farm Animal Breeding and Reproduction, a vision for 2025’, the FABRE Technology Platform (2006; http://www.fabretp.org/images/vision.fabretp.def1.pdf) described the farm animal of the future as ‘robust, adapted and healthy’. The importance of robustness-related traits in breeding objectives is progressively increasing towards the production of animals with a high production level in a wide range of climatic conditions and production systems, together with a high level of animal welfare. As stated by Knap (2009), ‘Sustainable breeding goals combine robustness traits with production traits to such an extent that selection balances genetic change in production potential with genetic change in environmental sensitivity’. Indeed, when selection focuses on production traits only, the above-mentioned functional traits are likely to become compromised (Rauw et al., 1998; Star et al., 2008; Knap and Rauw, 2009; Siegel et al., 2009; Veerkamp et al., 2009). The current evolution of animal production systems (increase of economic pressure, diversification of production environments, reduction of individual animal management, increase of parasitic load with outdoor production) combined with global warming increases the importance of adaptation and robustness traits in sustainable breeding goals.