The effect of grass cultivars differing in heading date and ploidy on the performance and dry matter intake of spring calving dairy cows at pasture Noel Gowen, Michael O'Donovan, Imelda Casey, Myles Rath, Luc Delaby and Gearoid StakelumAnim. Res., 52 4 (2003) 321-336DOI: https://doi.org/10.1051/animres:2003025