A mild climate, fertile soils and rainfall are natural resources that enable abundant grass growth and, consequentially, potential for grass-based milk production in temperate countries such as Ireland and New Zealand. This type of climate permits dairy cows to graze outside for up to 300 days a year (O’Donovan et al., 2011) and provides a comparatively low-cost, high-quality and sustainable diet for dairy herds and reduces reliance on purchased feeds with a higher cost and environmental footprint (Belflower, 2010; Rotz et al., 2020). Grazed pasture is crucial in underpinning dairy production and farm profitability (Hanrahan et al., 2018; Neal and Roche, 2020) and approximately 0.44 of the difference in net profit per hectare between farms can be explained by grass utilised per hectare. But this competitive advantage is dependent on the efficient production and utilisation of grazed grass.