Sweet potato (Ipomoea batatas)
Local names: Hindi: Shakrkand Manipuri: Mangra, Tamil: Sarkaraivallikizangu Kannada: Sihigensu Gujarati: Rataru, sakkareo Telugu: Genusu Malayalam: Madhurakkilannu
The sweet potato is a very important tropical plant whose tubers are widely grown for human consumption and as a commercial source of starch. Production of sweet potato was about 1.12 million MT during 2009-10 in India. Sweet potato is a creeping plant with perennial vines and adventitious roots, some of which produce swollen tubers.
Nutritive value
Low protein, fat and fibre were found in the roots, but the high nitrogen-free extract fraction in this tuber is indicative of its potential value, mainly as an energy source. The vines have a lower carbohydrate content but higher in fibre and protein and their principal nutritive value is as a source of vitamins and protein. Carbohydrates generally make up between 80-90% of the dry weight of sweet potato roots, but the uncooked starch of the sweet potato is very resistant to the hydrolisis by amylase. When cooked, their susceptibility to the enzyme increases. Thus, after cooking, the easily hydrolysable starch fraction of sweet potato increases from 4 to 55%. The content of trypsin inhibitors of the raw sweet potato roots could decrease the protein digestibility in mixed feed. The vines will not produce this effect because they do not contain them in great quantities. This trypsin inhibitor could be destroyed or lowered by preheating raw sweet potato roots. The fresh tubers are palatable for cattle and sweet potato meal was found to be 90% efficient as a feed for lactating cows when compared to corn meal feed.The vines serve as a nutritive and relished green feed for cattle. The feeding value of vines is close to that of alfalfa. Fresh sweet potato vines are palatable to cattle and a cow weighing 400-500 kg can consume 50-70 kg daily. An increased proportion of fresh sweet potato vines produced more milk. The supplementation of sweet potato-forage improves feed intake and weight gain of young bulls fed sugar cane stalks.
