The holy grail from a farmer’s perspective is growing high-yielding swards of high-quality grass that can be easily and efficiently converted to meat, milk or winter feed, with minimal inputs and loss to the environment.

Achieving this is difficult. Perennial ryegrass swards, which have dominated grass-based dairy advice for the last 100 years, are high-yielding and digestible, but they have a relatively high nitrogen requirement and their growth pattern is not very uniform, ranging from zero to 100kg DM/day from winter to summer.