How fast can we change resilience and efficiency through breeding and management?

The efficiency of dairy cattle has to be balanced against their resilience to disease challenges but also their individual responses to internal and external environmental stressors. A holistic approach is required as both efficiency and resilience have to be defined in a broad sense. Efficiency is more then only productive efficiency, the dilution of maintenance and indirect cost effects have to be considered through reduced feed, rearing, health and replacement costs; environmental costs should also not be forgotten. With this broader definition of efficiency, resilience as a major factor to reduce health costs contributes directly to a holistic view on efficiency. An underlying issue is here the old question if we change environments to address the needs of animals, or do we change animals to adapt to the environment. Previously, it was common understanding to prioritize first approach. However changing profoundly and suddenly environments and therefore management practices is difficult, disruptive and costly. However the EU FP7 project GplusE develops Hazard Analysis Critical Control Point (HACCP) and Evolutionary Operation (EVOP) based methods to optimize dairy cow management in a given production circumstance. The important advantage of this approach is that it is not disruptive but allows a slow but continued process of optimization. It is therefore not very different from the continuous process of cumulative optimization of the animals achieved by genomic selection, another important research topic of the GplusE project. Both approaches are complementary optimization opportunities for resilience and efficiency. However they are not possible without the development of appropriate response variables describing efficiency and resilience. The GplusE project has made the choice to develop novel milk based bio-markers and proxies for, often difficult to obtain; traits describing efficiency and resilience. Changes through breeding or management have to be continuous and well balanced considering the whole system. Changing environments or animals too fast should be avoided as this may lead to unforeseen consequences