The Voluntary Forage Intake of Heifers Grazing a Diminishing Supply of Crested Wheatgrass
Journal of Animal Science
Intake estimates for Angus heifers grazing a declining quantity of available crested wheatgrass forage were obtained during the summer grazing seasons of 1978 and 1979. The study was conducted on rangelands in Central Utah that are characteristic of the Eastern Great Basin. Organic matter intake (OMI) was measured by total collection procedures during five periods each year following forage maturation. Available forage was reduced prior to each succeeding intake measurement within each year by grazing animals. In the first year, OMI averaged 1.2% of body weight as available forage decreased from 920 to 140 kg/ha. In the second year, OMI averaged 1.3% of body weight as available forage decreased form 880 to 280 kg/ha. Intake differences between periods within years were not significant. In vitro organic matter digestibility ranged from 33 to 40% in the first year and 34 to 43% in the second year.
Havstad, K., Nastis, A. and Malechek, J. (1983). Voluntary forage intake of heifers grazing a diminishing supply of crested wheatgrass. Journal of Animal Science, 56(2): 259-263.