Herrera, F., Balocchi, O., Riegel, R., Keim, J.P.
Original Research Article,
The aim of this study was to determine the effect of changing the potassium/sodium ratio in a Lolium perenne L. sward on ingestive behaviour of lactating dairy cows. The experiment considered 5 K/Na ratios that were organised in 10×20 m plots arranged in three randomized complete blocks. To generate the different K/Na ratios, 0 kg K2O-0 kg Na (control), 50 kg Na ha-1, 100 kg Na ha-1, 400 kg K2O ha-1 and 800 kg K2O ha-1 were applied to the different treatments. Plots were grazed by lactating dairy cows, which were offered an herbage mass of 6 kg DM cow-1 (above 5 cm ground level) during a 6 h grazing event. Nutritional composition, K and Na concentration in the pasture, pasture height and herbage mass, as well as pasture removal and grazing behaviour were assesed.