Among our domestic animals the sheep has an outstanding virtue; if required to, it can live and produce, at least wool, on the most ' sparse and inhospitable grazings, and because of this ability it has always tended to be relegated to the less favourable environments for plant and animal growth. On the other hand, as we well know, it can, when given the opportunity, produce at high levels on the highly productive pastures that are a feature of our modern farming.