Better Farming Series 46 - Use of Cassava and Sweet Potatoes in Animal Feeding (FAO, 1995, 47 p.) Sweet potatoes as an animal feed Use of sweet potatoes in pig feeding Use of sweet potatoes in rabbit feeding Use of sweet potatoes in chicken feeding Use of sweet potatoes in ruminant feeding

Better Farming Series 46 - Use of Cassava and Sweet Potatoes in Animal Feeding (FAO, 1995, 47 p.)

Sweet potatoes as an animal feed

Use of sweet potatoes in pig feeding

175. In many parts of China, farmers fatten their pigs mainly on sweet potatoes. They have known the value of sweet potatoes for a long time.

Pigs

176. Chinese farmers also make dried chips from sweet potatoes, store and use them throughout the year. Some make a silage with sweet potato tubers to feed their pigs.

Feeding fresh tubers to pigs

177. Fresh tubers can be chopped and fed to pigs. Pigs readily eat them.

Fresh tubers

178. Fresh sweet potato tubers are better feeds than fresh cassava roots because:

- they have more protein;
- they have no cyanide.

179. However, tubers from some cultivars have high levels of trypsin inhibitor. If you feed these tubers without cooking, animals will not digest enough protein. They will not grow well.
180. You can suspect high levels of trypsin inhibitors if your pigs do not grow well when fresh sweet potatoes are used as the main feed.

181. If you suspect a high level of trypsin inhibitor in the tubers, you must boil them before feeding. Boiling will destroy the trypsin inhibitor.

Boiling the tubers

182. When you boil the tubers, digestibility will be increased; more protein will become available for the growth of animals.

183. You can feed the pigs with fresh sweet potatoes as much as they like.

184. You have learned earlier that you need to give protein feeds with cassava roots. Similarly sweet potatoes cannot be used as the sole teed. They must be fed along with protein feeds.

Food

Feeding dried chips to pigs

185. Dried sweet potato chips can be fed to pigs just like the chopped fresh tubers. In China, this is a common way of feeding pigs.

186. When you feed dried chips it is best to moisten them with water. Then the pigs like them better.

Feeding sweet potato meal to pigs

187. Sweet potato meal is a good energy feed. It can be mixed with other feeds and used in compounded rations, just as cassava root meal is used.

188. It can be used in compounded rations instead of cereal grains. It must be mixed with protein feeds, mineral supplements and vitamin supplements.

189. The energy that pigs can get from sweet potato meal is similar to that they get from cassava meal and maize. Sweet potato meal can completely replace maize in pig rations.

Sweet potato

190. However, if you suspect trypsin inhibitor may be a problem in the meal, it is safe to replace only 50 percent of the maize in your pig ration with sweet potato meal.

191. If you are now using 7 kg of maize when mixing a 10 kg pig ration, instead you can use 3.5 kg of maize and 3.5 kg of sweet potato meal.

192. Some examples of compounded pig rations with sweet potato meal follow. These will give you an idea as to how to mix the rations.

Pig rations using potato meal

Ingredient	Ration for
	growing pigs	finisher pigs
	Parts
Maize	35	35
Sweet potato meal	35	35
Soybean meal	20	18
Fish meal	5	3
Sweet potato vine meal	4	8
Bone meal	2 5	2.5
Vitamin-mineral premix	0 3	0.3
Salt	0.2	0.2
Total	100	100

193. Note that sweet potato vine meal is used in these examples. Sweet potato vine meal can also be used in animal feeding.

194. When you mix high levels of sweet potato meal the ration will become dusty. You must wet the ration with water before feeding to pigs.

Feeding tuber silage to pigs

195. Sweet potato tubers can also be preserved as a silage. Making sweet potato tuber silage is similar to making cassava root silage.

196. Pigs readily eat the silage. You can feed any amount of silage to pigs. You must feed the silage along with protein feeds to get good results.

Use of sweet potatoes in rabbit feeding

197. Sweet potato tubers are good energy feeds for rabbits. You can feed them as:

- chopped, fresh tubers;
- dried chips;
- meal.

198. You can feed the rabbits with sweet potatoes in the same way as you feed the pigs. You must take the same precautions.

Use of sweet potatoes in chicken feeding

199. How much sweet potato meal you can put into a ration will depend on the age of the birds.

200. In rations of young birds that are less than eight weeks old, you must not use more than 20 percent sweet potato meal. If you are mixing a 10- kg ration, you must not use more than 2 kg of sweet potato meal.

201. As the birds grow bigger, you can gradually increase the amount of sweet potato meal that is used. In rations for laying chickens you can use up to 30 percent sweet potato meal.

202. Like the cassava root meal, sweet potato meal is dusty and powdery. When you use high levels of sweet potato meal, you will face similar problems.

203. Some examples of chicken rations with sweet potato meal follow.

Chicken rations using sweet potato meal

Ingredient	Ration for
	young chickens	Iaying chickens
	Parts
Maize	40	35
Sweet potato meal	20	30
Rice bran	5	6
Soybean meal	22	16
Fish meal	8	3
Sweet potato vine meal	3	3
Bone meal	1.5	2.5
Shell grit	-	0.4
Vitamin- mineral premix	0.3	0.3
Salt	02	0.2
Total	100	100

Use of sweet potatoes in ruminant feeding

204. Sweet potato tubers can be given to all ruminants. They can be fed as:

- fresh, chopped tubers;
- dried chips;
- silage.

205. If sweet potatoes are available at cheap prices, you can feed them as energy supplements along with locally available grasses:

- during the dry season;
- for fattening animals and milking animals.