Mid-winter protein, phosphorus, and digestibility of Chrysothamnus nauseosus subspecies.

Abstract

Little has been done to evaluate the mid-winter crude protein, phosphorus, and in vitro digestibility of subspecies and accessions of rubber rabbitbrush (Chrysothamnus nauseosus ssp.) For those few studies that have been conducted, subspecies and accessional variation was not addressed. This study tested the hypothesis that certain subspecies and accessions of rubber rabbitbrush grown in a common garden on homogeneous soil would exceed other subspecies and accessions in crude protein, phosphorus, and in vitro digestibility. Also, the level of these traits for the various subspecies and accessions of rubber rabbitbrush were compared to other species of winter forages. Significant differences for all 3 traits occurred among subspecies and accessions. Some accessions of rubber rabbitbrush were ranked high in crude protein, phosphorus, and digestibility in comparison to other species of winter forages. Enough variation exists among subspecies and accessions that a selection program could result in the development of superior forms of rubber rabbitbrush to be used as a winter forage.