Evaluation of the nutritive value of kudzu (Pueraria lobata) as a feed for ruminants

Kudzu (Pueraria lobata) was separated into aerial (leaf and stem) and tuber (root) parts to determine its potential nutritive value as a feed for ruminants. Proximate analyses, together with measurements of neutral detergent fiber (NDF), acid detergent fiber (ADF), Ca, Fe, K, and Mg, and kinetics of in situ dry matter and in vitro dry matter digestion were performed. For the leaf, stem, and tuber parts, respectively, crude protein (17.5, 10.3, and 8.6%), NDF (48.1, 73.1, and 39.8%), ADF (38.2, 44.0, and 53.3%), Ca (0.7, 0.1, and 0.4%), Fe (162.3, 156.5, and 3600 mg kg−1), K (1.0, 1.0, and 0.3%), and Mg contents (0.3, < 0.1, and 0.1%) were comparable to other forages commonly fed to ruminants. In situ digestion kinetics of the aerial and tuber parts of kudzu, respectively, estimated that 29.1 and 38.1% was soluble, 48.6 and 31.2% was potentially degradable, 22.4 and 30.7% was indigestible, and that the fractional rate of digestion was 10 and 7% h−1. The estimated fractional rate of digestion of kudzu was slower than values reported for lucerne hay, but seemed to compensate by having a higher potentially digestible fraction. In vitro dry matter digestion of the leaf and stem parts of kudzu (64.8 and 73.7%, respectively) were superior to values for lucerne and bermudagrass hays. The tuber part was similar in digestibility to lucerne, but more digestible than bermudagrass hay. As a whole, chemical composition and digestibility characteristics of kudzu were very comparable to other commonly fed forages which shows its potential as a feed for ruminants. Further study is needed to evaluate voluntary intakes and animal performance.