Potential forage value of some eastern Canadian sedges (Cyperaceae: Carex)

Abstract

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.