Potential of Industrial Sweetpotato As Livestock Feed in the Southeastern United States

The increased demand of crude oil globally has also increased the production of corn (Zea mays) for fuel ethanol production in the United States. The use of corn for ethanol has in turn increased the price of corn, which is also the primary energy component of animal feeds along with many food products. Studies were conducted to evaluate the feasibility of using industrial sweetpotato tuberous roots (Ipomea batatas) cultivar ‘Xushu,’ as a substitute for corn as the energy component of animal feed or as a protein source after fermentation and extraction of ethanol. Field studies evaluated the effect of nitrogen fertilizer rates (0, 50, 100, and 150% of recommended amounts) on yield, crude protein (CP), total digestible nutrients (TDN), and acid detergent fiber (ADF) of both fresh industrial sweetpotato tuberous roots and fermentation by-product of these same roots. No differences were observed in yield between the different nitrogen fertilizer rates. Feed analysis revealed that the energy (TDN) levels of fresh sweetpotato were similar to corn, the current standard energy component in commercial livestock feeds. Feed analysis of sweetpotato fermentation byproduct revealed CP levels that were half to two thirds the amount in soybean (Glycine max), the standard protein component in livestock feeds. The TDN and CP levels in this research suggests that both fresh industrial sweetpotato tuberous roots and industrial sweetpotato fermentation by-product could be used as an energy and protein source respectively in commercial livestock feeds. Sweetpotatoes were also calculated to out yield corn’s TDN per acre by over 20 times making it an attractive alternative energy component of livestock feed.