Effect of level of nitrogen fertilization and protein supplementation on herbage utilization by grazing dairy cows. I. Herbage intake and feeding behaviour JL Peyraud, L. Astigarraga, P. Faverdin, L. Delaby and M. Le BarsAnn. Zootech., 43 3 (1994) 291DOI: https://doi.org/10.1051/animres:19940358