The effects of legume seeds on the lactation performance of dairy cows fed grass silage-based diets

The aim was to study if locally produced organic legume seeds as protein supplement could improve the performance of dairy cows. The experiment was a cyclic change over design were the control diet consisted of grass silage and barley (60:40) on a dry matter (DM) basis. Barley was replaced with rapeseed expeller (RSE), or isonitrogenous supplements of peas, untreated field beans (UFB), heat-treated FB (TFB) or a lower level of TFB (TFB-low) that provided the same dietary metabolizable protein concentrations as of UFB. None of the legume protein supplementations had effect on DM intake (DMI) neither on energy corrected milk yield compared to control. The RSE treatment increased milk (24.8 vs. 23.6 kg d(-1)) and protein yield (913 vs. 863 g d(-1)) compared to other protein supplements. Heat-treated FB had no effect on DMI, milk or protein yield compared to UFB. Only RSE resulted in improvements in dairy cows performance in relation to the control diet.