Animal Production from Grassland was to have been the theme of the Summer Meeting in 1971 but, owing to circumstances prevailing in Northern Ireland at that time, most reluctantly the Society had to cancel the Meeting. However, because of the importance of the theme selected for that meeting, it was decided to invite the authors to present their papers at a Special Topic Session at the 1972 Winter Meeting. In introducing this group of papers, there are two points which should be made.