Nutritive Value of Sweet Potato Forage (ipomoea batatas (L.) Lam.) as a Ruminant Animal Feed.

Abstract

Four varieties of sweei potato (Ipomoea batatas) (L.) Lam.) were tested for their forage production and nutritive value as a ruminant feed in subtropical Queensland. Forage was harvested 63, 104, 159 and 199 days after planting and assessed for yield and nutrient composition. Forage yields varied with age and variety. Red Abundance was the most productive variety, yielding 221 dry matter (DM) per ha at 199 days. The DM contents of all varieties were initially low (79 to 119 g/kg) and increased (to 132 to 183 g/'kg) with age, whereas the protein contents decreased with age from 146to103 g/kg DM. Neutral detergent fibre contents varied little from a mean of467g/kg DM, both between varieties or over the growing period The mean DM digestibility coefficient of material obtained at 199 d was 0.76 and varied little between varieties. These forage production and nutrient content data suggest that sweet potato may provide a useful source of forage for ruminants.