Resilience, tolerance, robustness and genotype x environment interaction in Merino sheep breeding

The concepts of environmental resilience, robustness and tolerance in domestic livestock species are discussed in general and illustrated using specific examples from the Australian Merino industry. It is discussed how these concepts relate to the more commonly known notion of genotype x environment (GxE) interaction. The Merino sheep breed consists of genetic strains that have been selected for suitability to specific environments and has reached a high level of pecification for quality wool production. At the same time Merino sheep produce across a wide range of climatic environments and next to wool contribute substantially to Australia's prime lamb production. By gathering scientific and anecdotal evidence, it is explored if the Merino sheep breed is resilient, robust or tolerant to environmental fluctuations, including the environmental differences that are generated by the stud and commercial sector. It is outlined how GxE interaction is currently considered in MERINOSELECT, the national genetic evaluation system for Merino sheep, and future opportunities to consider environmental resilience, robustness or tolerance in livestock breeding programs.