6. USE OF CASSAVA IN LIVESTOCK FEEDING IN WEST, EASTERN, CENTRAL AND SOUTHERN AFRICA

6.1 Historical perspectives, research and development activities

Historically and presently, cassava plays a minor role as an ingredient in livestock feeding in sub-Saharan Africa. This is largely due to cassava often being more expensive than imported maize for this purpose in Africa. The scenario of usage varies among different countries of sub-Saharan Africa.

In West Africa, Nigeria provides an interesting case of how government policies can influence the use of cassava as a livestock feed. In 1985 the Government of Nigeria banned the importation of maize and compelled livestock feed mills to look for local crop sources such as cassava. As a result the proportion of total cassava production used as livestock feed increased from 3-10 percent from 1985 to 1990. Though the ban on maize importation was lifted, cassava usage in the feed milling industries in Nigeria continued. However, due to a sharp rise in the price of cassava which follows its cycle of glut (excess cassava supply), the market price of cassava products is not competitive with maize for livestock feeding hence its utilization dropped to about 5 percent of total production in 2000 (Table 13). In Ghana cassava usage for feeds stands at 2 percent of total production while in Côte d'Ivoire it was 5 percent for 2000. In Liberia less than 1 percent of total production is used for intensive animal feeding (Ravindran and Ken Kpen, 1992).

In East Africa the usage of cassava is important for United Republic of Tanzania and Uganda. Cassava in livestock feed was 0.5 percent of total production in United Republic of Tanzania between 1991 and 2000. Lekule and Sarwatt (1992) indicate that it is only when grains are in very short supply that small quantities of cassava are included in feed in United Republic of Tanzania. In Uganda 25 percent of cassava was used for feed from 1991 to 1995 and increased to 27 percent in 2000 (Table 17). Cassava usage as feed in Ethiopia, Kenya and the Sudan is not significant.

Cameroon leads in usage of cassava for feed in Central Africa with percentage use increasing from 9.95 percent in 1991 to 10 percent in 1995 and 2000 (Table 21). The use in Chad was static at about 5 percent for the period 1991 to 2000 while in the D.R. of the Congo the quantity used for feed was minimal being static at about 0.25 percent for the same period.

The use of cassava for animal feed is important only in Madagascar in the South African region with about 10 percent of total production used in commercial feed milling (Table 25). In South Africa cassava is a recently introduced crop being presently used mainly in starch production. In Zambia the market price of cassava is higher than maize thus making it not competitive as a livestock feed (Mokuka, 2002 personal communication).

Resource and development activities on cassava in livestock feeding in sub-Saharan African date back to four and half decades when Oyenuga and Opeke (1957) demonstrated the satisfactory performance of intensively reared pigs on fresh and boiled cassava-based rations. Studies on pigs as well as poultry cattle, sheep and goats in different countries of sub-Saharan Africa are presented in Table 26.

6.2 Production utilization pattern of usage in traditional and commercial settings

The usage of cassava in traditional settings is largely by feeding of fresh or sun dried cassava roots and its by-products to livestock largely reared around homes in cassava processing sites. Peeled roots are normally fed to pigs while unpeeled roots are usually fed to cattle. The roots can also be sun dried after chopping and spread to dry on bare ground or on rock surfaces. Cassava leaves are also normally sun dried in the open or may be dried in ashes, but this takes longer, 10-15 days as in United Republic of Tanzania (Lekule and Sarwatt, 1991). Cassava leaves are also fed fresh to goats but varieties are selected to avoid poisoning. Also wilting of leaves is carried out but short-term wilting, three to four hours, usually results in toxic levels but 48 hours wilting is safe. Cassava peel in fresh or dried form also provides complimentary energy to cattle, sheep and goat in traditional systems.

Cassava and its by-products are of a highly variable quality and usually contain significant levels of contaminants like sand and microbial organisms like Aspergillus flavus. These can have more deleterious effects than the residual cyanide in cassava. Since cassava is usually fed as a supplement to livestock in traditional systems, the levels of inclusion vary depending on their availability as it is irregular. Being basically a human food in sub-Saharan Africa, only the wastes are predominantly fed in traditional systems.

Table 26. Cassava in feeding of different livestock species in sub-Saharan Africa

Cassava also plays an important role in pastoralist cattle feeding. In Nigeria during the dry season, free ranging cattle are moved southwards in search of pasture. At the peak of the dry season it is usually cassava farms alone that retain their 'greenness'. It is usual for cattle to ravage such farms consuming the foliage and trampling on the roots. Communal clashes resulting from this occurrence are attaining prominence when cattle rearers are not settled. The potentials for utilizing wastes of cassava which varies in different countries of sub-Saharan Africa can be up to 52 percent of total production as in Nigeria (Table 13), 10 percent in Uganda (Table 17), 15 percent in Cameroon (Table 21) and 20 percent in Malawi (Table 27); the respective tables show the vast potential of this root crop in traditional systems.

Cassava usage in commercial settings is usually in the form of dried root chips which are milled into flour before incorporation into compound feeds usually for commercial poultry. Processing cassava into chips involves harvesting of the roots and peeling. This is usually unaccompanied by washing. They are usually chopped with cutlass into bits or left as whole peeled storage roots and sun-dried on bare ground or where available, on rocks. The quality of such chips varies greatly being highly contaminated with sands and microbes when dried on bare ground and in humid areas where cassava cultivation is prominent. In the drier and rocky areas the chips are cleaner, whiter, drier and less contaminated. Recently, simple machines have been developed for chipping cassava roots before drying. This consists of a driven disc with radial chipping slots fitted with cutting blades. These chips are sold to commercial feed millers who mill this into powder. This process releases a lot of dust from the cassava during milling and an appreciable quantity is thereby lost. Levels of inclusion of cassava in poultry feeds is between 5-10 percent in Nigerian feed mills and such mixes include full fat Soya to ensure reduction of dust in such compound feeds. As an alternative, palm oil is added on farms that mix their own feed to reduce dustiness.

A cheaper and cost effective method for processing cassava into chips and pellets has been developed at the International Institute for Tropical Agriculture (Tewe and Bokanga, 2001). This involves harvesting the cassava roots, washing and chipping with a motor or manual driven chipper before sun-drying on cemented floor with turning twice daily using a rake. This procedure eliminates the peeling cost. This product is competitive with maize in the livestock feed industry as it is marketed at about 60 percent of the price of maize. The cassava chip can also be mixed with shredded and similarly dried cassava leaves mixed in a 4:1 ration cassava root meal: leaves milled and pelletized using a manual or motor driven pelletizer. The pelletizing process has been simplified by eliminating the need for drying before pelletizing. In this most recent technique the washed unpeeled cassava root is grated, dewatered and passed straight into the pelletizer where it is steamed and the resulting hot pellets are sun-dried or oven dried. The product is not only cost effective to the feed miller as compared with maize, but a cottage industry can be profitably sustained on this product which can be established at the farm gate rural level.

It should be noted that African cassava chips and pellets are not competitive in European livestock feed markets because of the high cost of production and transportation in Africa and from Africa. The recent experience of cassava chip production and export in Ghana is an example. Africa has been an unreliable supplier of pellets (Phillips, 1973).

According to Nweke et al. (2002), the production of cassava in Africa is notoriously unstable because of weather induced fluctuations in food production. Africa's unstable supply of cassava discourages European buyers who have a long history of relying on more stable Asian and Latin American suppliers. Africa cassava products are also low in quality because of the inefficient traditional processing methods.

6.3 Use of cassava as animal feed to enhance food security

In collaboration with national programmes, the International Institute for Tropical Agriculture (IITA) has developed high yields and stable cassava lines and many national cassava improvement programmes in sub-Saharan Africa have released improved cassava varieties resulting from IITA's work. Higher productivity is therefore being recorded in many African countries with Nigeria becoming the worlds leading cassava producer. The increase in cassava production needs to be matched with diversification of usage of this root crop beyond its traditional role of being a staple food on the continent. The cycle of glut, which follows excessive production of cassava in Nigeria and other countries in Africa, is a result of lack of alternative markets for this root crop. Cassava trade needs to be boosted to ensure that farmers can earn adequate income from it to empower them economically, sustain the production system and enhance food security on the continent. The development of new and alternative uses and products from cassava is therefore critical to its transformation from a staple food to becoming a livestock feed component and industrial raw material.

Alternative uses for cassava exist in its transformation into novel foods, livestock feeds, starches, ethanol and pharmaceutical products. Among these alternatives, livestock feeds appear to be the most promising because of the following reasons:

• the standards required for feed grade cassava products are not as stringent as for other products. The possibilities of packaging technologies affordable and practicable at the farm gate level for livestock feed cassava products are highly promising;

• with animal protein consumption projected to increase on the continent, there is tremendous potential for growth of the animal feed industry which is the main component of costs in livestock production. The possibilities of cassava playing a vital role in the supply of feed ingredient to the industry is also not doubted;

• availability of maize which is the main energy source in compound livestock feeds is being threatened as many African nations cannot afford importation of maize due to huge foreign debts and currency devaluation. Local production of maize is also hampered by escalating costs of fertilizer and unfavourable weather conditions in many African countries. The need for cassava as an alternative energy source becomes imperative in order to ensure adequate energy supply in livestock compound and supplemental rations.

With improved productivity, surplus cassava is anticipated in many African countries and this can lower farm prices for cassava products. As cassava is essentially an energy source, it is necessary for cassava farmers to earn income to enable them to purchase other feeds like cereals and pulses among others to ensure balanced nutrient in-take and maintain a healthy household. Failure to expand the cassava market at the rural level to livestock feed products will hamper the socio-economic status of cassava farming populace and therefore erode their food security. Thus, transformation of cassava into livestock feed ingredients therefore becomes imperative to prevent malnutrition and poverty among rural households which constitute over 90 percent of cassava producers on the continent.