Water salinity effects on performance and rumen parameters of lactating grazing Holstein cows.

Eighteen multiparous lactating grazing Holstein cows, 9 ruminally cannulated, average 136.1 +/- 14.6 days in milk, were randomly assigned to three treatments consisting of water containing different levels of total dissolved solids (TDS; mg/l): Treatment 1 = 1,000; Treatment 2 = 5,000 and Treatment 3 = 10,000, at the Experimental Dairy Unit at Rafaela Experimental Station (31 degrees 11'S latitude) during summer 2005.