This discussion is based on a simple assumption about the South Island dairy industry: the trend towards large herd size (>650 cows) and greater milk solids (MS) production is not going to abate in the near future. That being so, there are emerging features of herd nutrition management of these larger, higher producing herds that are both interesting and poorly described to date, and recent research by Lincoln University Animal Science, including the South Island Dairy Lameness (SIDL) project (2005-09), is relevant to some of these. In this paper, some aspects of the rumen impact of typical grazing strategies used for pasture management in lactation and for kale crops in winter on these large, high producing herds will be discussed.