Nutritive Value of Desmanthus Associated With Kleingrass During the Establishment Year

Abstract

Seasonal variation in production and quality of warm-season grasses is a limitation for livestock productivity. The use of high quality forage legumes to aid in overcoming this problem can be a management alternative. The objective of this study was to evaluate the nutrient content of kleingrass (Panicum coloratum L.)-bundleflower (Desmanthus sp.) mixtures during the establishment year. Plots were drilled at a 0.15 m row-spacing with kleingrass sown either alone or in association with Illinois bundleflower (Desmanthus illinoensis [Michx.] MacM.) or desmanthus (Desmanthus pubescens [L.] Willd), which was previously identified as Desmanthus virgatus. Spacings of 0.30, 0.60, and 0.90 m between rows of bundleflower were used. Plots were planted in April and nutritive value was determined on samples harvested at 60, 90, and 120 days after planting. Age reduced kleingrass crude protein (CP) and increased fiber concentration. The CP concentration of desmanthus leaves was greater than that of Illinois bundleflower; however, the CP on a whole-plant basis was greater in Illinois bundleflower. Associations had greater CP yield than did the kleingrass monoculture. The tannin content was higher in desmanthus than in Illinois bundleflower. In both legumes the leaves had the greatest tannin concentrations, with a mean of 2.1% and 1.69% in desmanthus and Illinois bundleflower, respectively. With the exception of calcium (Ca), mineral content declined with increased age in both legumes and the grass. Levels of potassium, sodium, copper, and manganese were greater in kleingrass than in the legumes, while the legumes had greater concentrations of Ca and magnesium (Mg). Phosphorus and zinc concentrations were similar for kleingrass and legumes. The legumes did not affect the nutrient content of kleingrass when established in association, and the high CP of both legumes and their high levels of Ca and Mg suggest that animals grazing kleingrass-desmanthus associations may benefit nutritionally.