Browsing Journal of Range Management, Volume 47, Number 3 (May 1994) by Subjects
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Nutrient quality of bluebunch wheatgrass regrowth on elk winter range in relation to defoliationEffects of defoliating bluebunch wheatgrass (Agropyron spicatum [Pursh] Scribn. & Smith) to increase the quality of regrowth available on Rocky Mountain elk (Cervus elaphus nelsoni Bailey) winter range were studied from 1988 through 1990. Percent calcium, phosphorus, in vitro dry matter digestibility (IVDMD), and available forage (kg/ha DM) of regrowth present on control, spring-defoliated, and fall-defoliated plots were determined in November of 1988 and 1989, and April of 1989 and 1990. Spring conditioning did not affect the percentage of calcium and phosphorus, or available forage compared to the current year's growth in either November or April. Fall conditioning increased digestibility and increased the phosphorus concentration, but decreased available forage compared to the control and spring-conditioned forage in November. Fall conditioning may create a deficit of forage if regrowth is not achieved. Additional research is needed on defoliation during the early phenological time-period of bluebunch wheatgrass to improve the forage quality of elk winter ranges.
Potential forage value of some eastern Canadian sedges (Cyperaceae: Carex)The relationship between forage value and various factors, including sectional classification, species, moisture, light, and date and year of collection, was explored with analysis of variance in 317 collections representing 77 species of Carex. Most of the sedges analyzed would exceed the energy required for livestock maintenance. There was great variability within and between species and sections in forage values defined in terms of crude protein, acid-pepsin digestibility, and acid detergent fibre content. Some species, such as C. praegracilis, have crude protein levels of about 15%, acid-pepsin digestibility exceeding 33%, and acid detergent fibre less than 33%, making them equivalent to a good quality grass hay. It was not possible to make generalizations about correlation with light and moisture, but rhizomatous species had higher acid-pepsin digestibility (P < 0.10) and lower acid detergent fibre (P < 0.01) than caespitose species. Forage quality was highest in the beginning of the season. Crude protein decreased 0.04 to 0.09% units/day and acid-pepsin digestibility declined 0.06 to 0.11 units/day. In 2 of the 3 years, acid detergent fibre increased significantly (P < 0.01) over time. The classification system appears to be useful in identifying species and species groups with the greatest forage potential. Some sedge species with relatively low forage value are nevertheless utilized by cattle. Natural habitats and native forages, such as sedges, may be far more valuable than is currently realized, and the trend toward increasingly efficient landscape use will require a better understanding of their value and management.