The high fibre content of cassava leaves makes them unsuitable for poultry if fed at high levels. However their high protein and their availability as a by-product make them valuable.
Most authors report a decrease in growth performance when cassava leaf meal (CLM) is introduced in diets and feed intake can also be affected (Eruvbetine et al., 2003; Onibi et al., 2008). Performance is generally maintained at low levels of CLM (Trompiz et al., 2007; Iheukwumere et al., 2007) though adverse effects are sometimes observed with levels below 5% (Akinfala et al., 2002). Some authors report acceptable performance with higher rates of CLM (10 to 20%) when methionine and energy are added (Ross et al., 1969) or if pelleting is applied (Sankaravinayagam et al., 1999). Whole crop cassava meal, composed of leaves and roots, has also been tested, and the results are similar to a proportional introduction of CLM in a complete diet, i.e. a degradation of performance (Eruvbetine et al., 2003; Akinfala et al., 2002). Leaf protein concentrate has the same depressive effect as CLM (Fasuyi et al., 2005). Supplementation with enzymes did not improve significantly the performance of broilers fed CLM (Silva et al., 2000). CLM should replace other fibre-rich resources, such as alfalfa, copra meal or cottonseed meal (Ravindran, 1993).
In typical diets, the introduction of more than 5% CLM is not recommended, and the energy and amino acid (particularly methionine) levels have to be adequate.
Due to palatability problems, a limit of 5% has been suggested for layer diets (Buitrago et al., 2002). Cassava leaf protein concentrate has been used up to 8% without adverse effects (Oludare, 2006). An advantage of CLM inclusion at low levels in layer diets is the supply of natural xanthophylls, which have a positive effect on yolk coloration (Ravindran, 1993).
In an experiment with Japanese quails, the introduction of up to 10% CLM or alfalfa meal did not affect growth performance (Ravindran et al., 1983). Both CLM and alfalfa meal produced the same increase in feed intake, which reduced feed efficiency.
Fruit coat meal
Under some conditions, cassava can flower and produce fruits that can be used in animal feeding. In an experiment with cassava fruit coat meal as a substitute for wheat bran in broiler diets, performance was maintained up to a maximum of 15% of the diet (Iyayi et al., 2005). However, the results suggested a low digestibility of organic matter. It is therefore recommended that this product is used at low incorporation rates, but only if the feed formulation can ensure sufficient energy.