109. Did you know that cassava leaves can be used as an animal feed? If you did not, read this section carefully. You will learn about:
- the feed value of cassava leaves;
- how they can be processed;
- how they can be used in animal feeding.
110. Cassava leaves can supply many nutrients that are necessary for animals. They are a good protein feed.
111. For ruminant animals, you can feed both the leaves and the tender stems. This is called cassava forage.
112. For pig and chicken feeding, you must strip the leaves, dry them and grind them into a meal. The milled product is called cassava leaf meal. By drying 100 kg of fresh cassava leaves, you can prepare about 20-25 kg of meal.
113. The amount of leaves that you can get will vary depending on the cultivar that you have planted. Some cultivars have more branches and produce more leaves than others.
114. The amount of leaves that you can harvest from a plant also varies, depending on:
- the age of plant;
- the climate in your area;
- soil fertility.
115. You can produce leaves in three ways. We will look at each of these possibilities.
Growing for roots
116. Farmers grow cassava mainly to harvest the roots. When you harvest the roots, you can save the leaves to feed animals.
117. You will not get many leaves when you collect them at root harvest. The leaf yields will be low.
Growing for roots and leaves
118. You can also harvest the leaves while the cassava plant is growing and while the roots are being formed.
119. In this way, you can increase the leaf yields. However, you must plan carefully when and at what intervals you should harvest the leaves.
120. If you harvest the leaves too frequently, the roots will not enlarge. You will get few smaller- sized roots.
121. If you plan to harvest the leaves while the plant is growing, you must make sure that the root yields are not affected.
122. In short- season cultivars, you must harvest the leaves only once while the plant is growing. Then the root enlargement will not be affected and you can still get good root yields.
123. In long-season cultivars, you can obtain at least two leaf harvests while the plant is growing and still get acceptable root yields.
Growing for leaves only
124. You can also plant cassava for the sole purpose of harvesting leaves.
125. In parts of Brazil, farmers plant cassava to produce leaves only. Leaves are harvested, dried, ground into a meal and sold for mixing in compounded rations.
126. When you plant cassava for leaf production only, you can plant it with closer spacing. You can have about 60 000 plants to the hectare.
127. This is much closer planting than that used for root production. For root production, you plant only 10 000 plants to the hectare.
128. You can start the first leaf harvest four months after planting and then harvest at three-month intervals.
129. In Venezuela, with this type of cultivation practice, leaf dry-matter yields of over 21 000 kg to the hectare have been obtained. This is a high yield for any forage material.
130. Cassava leaves are a good protein feed. Even mature cassava leaves contain a lot of protein. Dried mature cassava leaves can give about 200 g of protein to the kilogram.
Dried mature cassava
31. Let us see the amount of protein that is supplied by 1 kg of alfalfa meal and different oilcakes. Alfalfa is a legume that is widely used in animal feeding in cold climates.
132. You can see that mature cassava leaves have similar amounts of protein 10 coconut meal and palmkernel meal.
133. Young cassava leaves have even higher levels of protein. They can give 280-300 g of protein to the kilogram of dried leaves.
134. Cassava leaves are also a rich source of minerals and vitamins.
135. We know that all leaves are fibrous. Cassava leaves have a lot of fibre.
136. This fibre level does not cause any problems to ruminants. Ruminant animals can digest and use the fibre for energy. Cassava leaves are good feeds for ruminants.
137. For pigs and chickens, this high fibre level can cause problems. This means that cassava leaves must be used within limits in pig and chicken feeding.
138. Cassava leaves are rich in pigments. This is useful in chicken feeding.
139. As with cassava roots, cassava leaves contain cyanide. In fact, fresh cassava leaves have more cyanide than the roots.
140. By simple drying of the leaves in the sun, you can eliminate most of the cyanide present in cassava leaves.
141. You have to chop and wilt the leaves before drying in the sun.
142. While wilting, you must regularly turn the leaves over. Otherwise fermentation may occur and spoilage may start.
143. After wilting, the chopped leaves must be uniformly spread over a drying area. They will dry quickly.
144. Once well dried, they can be collected and ground into a meal. Meal can be stored in bags or gunny sacks.
145. Dried cassava leaves and cassava leaf meal have excellent storage qualities. Insects and moulds will not attack them. They can be kept in dry places for over a year and used when necessary.
146. The chicken mash which you purchase from dealers usually has a leaf meal in it to supply the pigments and to improve the colour of egg yolk and colour of skin of meat birds. In a 10- kg mash, 300-500 9 of leaf meal is usually included.
147. In North America and Europe, alfalfa meal is the popular leaf meal used in chicken feeds. It is also known as lucerne meal.
148. In warm climates, cassava leaf meal can be used for this purpose. The feed value of cassava leaf meal for chickens is equal to that of alfalfa meal.
149. In some tropical countries, Leucaena leaf meal is used to supply the pigments in chicken rations. Leucaena is a tree legume. It is also called ipil-ipil.
150. Cassava leaf meal has a better feed value than Leucaena leaf meal.
151. For the best results, you must use about 3 to 5 percent cassava leaf meal in your rations.
152. You have learned earlier (in Paragraph No. 77) about some examples of chicken rations with cassava leaf meal.
153. You have also learned earlier (in Paragraph No. 131) that cassava leaf meal has a protein content similar to those of coconut meal and palmkernel meal.
154. Therefore you can include cassava leaf meal instead of some oilcakes in chicken rations. In Sri Lanka, cassava leaf meal has been used in levels of up to 10 percent in chicken rations instead of coconut meal.
155. Cassava leaf meal can be included at levels of up to 10 percent in compounded pig rations. In a 10- kg ration, you can use up to 1 kg cassava of leaf meal.
156. If you use higher levels of cassava leaf meal in rations for fattening pigs, they will not fatten well.
157. Rations also become powdery when you use high levels of leaf meal. But pig rations are normally mixed with water and fed. Therefore this is not a big problem.
158. In areas where coconut meal is used for pig feeding, cassava leaf meal can be used instead of coconut meal. As a substitute for coconut meal, it can be used at levels of up to 20 percent in pig rations.
159. In tropical climates, the grasses mature and flower quickly. They quickly become fibrous and have poor digestibility and low protein contents.
160. These problems are more severe during the dry season. The grasses are dry and are more fibrous. Animals will not get much digestible feed or protein by eating them.
161. Animals will not grow and may lose weight. To avoid this, you must feed quality forages with high protein, along with available grasses.
162. You can feed legumes that are high protein forages. In many areas, tree legumes are used to feed animals. Gliricidia, Leucaena, Sesbania and Acacia are some tree legumes that you may find in your area.
163. Cassava forage has a protein value equal to those of these tree legumes. Cassava forage includes leaves as well as the tender stems. It is a good supplementary feed for all ruminants.
164. To lower the cyanide level, you must wilt the forage for a few hours before feeding.
165. Animals like the wilted forage more than the fresh forage. They will eat more of the wilted forage than fresh forage.
166. When you first give cassava forage, you may find that the animals are reluctant to eat. Usually it takes two to three days before the animals readily eat it.
167. You can make a silage with cassava forage in three ways:
- by using cassava forage alone;
- by using a mixture of cassava forage and grasses;
- by using a mixture of cassava forage and roots.
168. When you mix the cassava forage with grasses available in your area and make a silage, you improve the quality of the silage. You will make a silage with more protein.
169. The method of making silage from cassava forage is similar to that used for making silage from cassava roots. You have also learned about making silage from grass in Booklet No. 12 (page 23).
170. The forage and the grasses must be wilted first and then chopped. Wilting is done to reduce the water content in the materials.
Forage and grasses
171. If you make silage with too much moisture, a lot of liquid will drain out of the silage. This liquid will remove nutrients. Too much moisture will also make the silage spoil.
172. You can avoid the problem of too much moisture by using layers of dry grass or straw between layers of chopped forages. Dried materials will absorb the excess moisture.
173. You can mix the chopped roots with the forage and make a silage. This silage will be well balanced. Roots will supply the energy and the forage will supply the protein.
174. In parts of Brazil, the whole cassava plant is used to make silage. Roots, stems and forage are chopped together, made into a silage and used to feed fattening cattle.