Henkin, Z., Beef Cattle Section, Newe-Ya'ar Research Center, Department of Natural Resources, P.O. Box 1021, Ramat Yishay, 30095, Israel, Department of Natural Resources, Agricultural Research Organization, the Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Perevolotsky, A., Department of Natural Resources, Agricultural Research Organization, the Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Rosenfeld, A., Department of Natural Resources, Agricultural Research Organization, the Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Brosh, A., Department of Animal Science, Newe-Yaar, Agricultural Research Organization, Israel
Provenza, F., Department of Wildland and Resources, Utah State University, Logan, United States
Silanikove, N., Department of Animal Science, Agricultural Research Organization, the Volcani Center, Rehovot, Israel

The aim of the present study was to determine the effect of polyethylene glycol (PEG) supplementation on grazing behaviour of beef cattle and on utilization of the woody components of a Mediterranean shrubland. Two experiments were conducted on two different sites in Northern Israel, Ramat Hanadiv (RH) and Hatal. On each site, the study area was divided into two paddocks, in one cattle were supplemented with 50 g PEG day- 1 per cow, while the other served as a control, with no PEG supplementation. In RH site the cows had free access to Prolix and in Hatal to poultry litter, both serving as a nitrogen supplement during the experiment. In the RH site, the consumption of Pistacia lentiscus, a shrub whose leaves contain high concentration of tannins, was found higher (P = 0.001) in the PEG group diet than in the control group. In Hatal site PEG increased foraging time by 18%, daily foraging distance by 15% and reduced the use of supplementary feed (poultry litter) by 20%. However, PEG did not affect the average cow body weight or water consumption on either site. It is concluded that PEG influences grazing behaviour of beef cattle on shrubby rangeland and increases the use of woody species with high tannin concentrations. © 2009 Elsevier B.V. All rights reserved.