Two grazing experiments using spring calving Frisian milking dairy cows, were conducted at Remehue Experiment Station, located in Osorno (10th region), Chile, 750 kilometers south of Santiago. Typical temperate climate permanent swards were used in the experiments. Experiment 1 (November 1993 to March 1994) had six treatments. Three different stocking rates: light (L), two cows x ha-1; moderate (M), four cows x ha-1, and heavy (H) six cows x ha-1; with and without supplementation with silage buffer fed once a day, offered ad libitum during 1 h after morning milking. Experiment 2 had three treatments, using the same stocking rates as in Experiment 1, with grazing and without supplementation. Productive parameters of cows and sward characteristics were recorded. Milk production per cow decreased as stocking rate increased, 23,2 22,9 and 21,8 L x cow-1 for L, M and H, respectively in Experiment 1; 24,2 24,3 and 21,4 L x cow-1 for L, M and H, respectively, in Experiment 2. Milk production per hectare, however, reacted in the opposite direction. Milk constituents were not affected neither under different stocking rates or with supplementation. Grazing behaviour was also recorded. Grazing time was not significantly affected by stocking rates, but it was decreased by supplementation: 550 and 475 min x cow-1, with and without supplementation, respectively. Increasing stocking rates up to six cows x ha-1, resulted in an increment of milk per hectare and a decrease in milk per cow. Supplementation allowed grazing surface releasing, which is specially important under sward restricted periods. White clover and perennial ryegrass parameters were also measured; no treatment effects were found.