Co-Authors:
Brosh, A., Beef Cattle Section, ARO, Newe Yaar Research Center, P.O. Box 1021, Ramat Yishay 30095, Israel
Henkin, Z., Beef Cattle Section, ARO, Newe Yaar Research Center, P.O. Box 1021, Ramat Yishay 30095, Israel
Shabtay, A., Beef Cattle Section, ARO, Newe Yaar Research Center, P.O. Box 1021, Ramat Yishay 30095, Israel
Dolev, A., MIGAL, Galilee Technological Center, Qiryat Shemona, P.O. Box 90000, Rosh Pinna 12100, Israel
Orlov, A., Beef Cattle Section, ARO, Newe Yaar Research Center, P.O. Box 1021, Ramat Yishay 30095, Israel
Aharoni, Y., Beef Cattle Section, ARO, Newe Yaar Research Center, P.O. Box 1021, Ramat Yishay 30095, Israel
Abstract:
Daily heart rate (HR) level presents a reliable indication of ruminant heat production (HP) and energy balance status, the basis for animal management decisions. Individual short intervals of measured oxygen consumption per HR (O2 pulse, O2P) are required for the accurate estimation of daily HP, by multiplying O2P with daily HR (the O2P-HR method). The O2P is relatively constant during the day unless the animals are exposed to intensive exercise or heat load. Diet energy concentration and consequently the metabolizable energy intake has minor effect the O2P; however, a significant increase of production rate affects O2P positively. Using a Global Positioning System (GPS) receiver and motion sensors combined with HP measurement by the O2P-HR method enable a reliable estimation of the energy cost of the activities of free-ranging cattle. For grazing cows the sum of energy costs of standing, grazing, and traveling ranged from 38 to 74 kJ•kgBW-0.75• day-1, or 5.8 to 11.4% of the total daily HP.