Grazing activities and bioenergetics of sheep on native range in Southern Peru

Abstract Grazing activity of herded Corriedale ewes on the Peruvian Puna was monitored by direct observation for 2 animal-days (11.5 h, daytime only) each month from June 1983 through March 1984. Sheep spent an average of 52% of the day grazing, 13% ruminating, 13% resting, 20% walking, and 2% drinking. Time spent grazing was negatively correlated with forage intake but was not correlated with forage availability. Grazing time was positively correlated with distance traveled and time spent walking, and negatively correlated with crude protein and ME intake. In terms of energy, grazing and walking each accounted for 45% of the daily energy expended on behavioral activities (walking, grazing, resting, and ruminating). Estimated total daily energy costs (i.e., for behavioral activities, production processes, and basal metabolism) ranged from 1.56 Mcal ME/ day in June to 3.32 Mcal ME/day in January. Lactation accounted for over 50% of the daily energy expended during December through March, and resulted in negative energy balances of up to 0.57 Mcal ME/day during that period.