Cassava foliage as an animal feed

Abstract

The place of the aerial part of the cassava plant as an animal feed is examined in this study. In the first part, a survey of the published literature reviewed the botanical and agronomic characteristics of the plant, the production of cassava forage, its chemical composition and nutritive value, the presence of cyanogene tic substances and the economic potential of widespread use.

Two experimental studies were undertaken to determine the nutritive value of cassava foliage for ruminants-. The first determined the effect of the different stages of maturity and the second the possibilities of using cassava foliage as a protein supplement for poor hay during the dry season. Twelve goats and twelve sheep were used in each experiment.

Experiment I comprised three different plant regrowths (tips = 10cm; half length = 25cm; full length = l|.0cm) and a sample of leaves and petioles. The results showed that the digestibility coefficients of the cassava tips were significantly better than the other samples. The absence of differences amongst the other samples showed that the nutritive value of the forage should be related to the physiological age rather than the height. All the treatments showed a positive nitrogen balance. High urinary nitrogen losses were recorded which, it is suggested, were related to the high solubility of the cassava forage protein.

In the second experiment, a poor dry season hay (Hyparrhenia sp) was supplemented with three different levels of cassava forage. Cassava forage supplementation linearly increased the dry matter intake, water consumption, and the digestibility coefficients of dry matter and organic matter. The neutral detergent fibre digestibility coefficients did not show any variation due to treatment, while those of acid detergent fibre and cellulose decreased linearly as the level of cassava forage in the diet increased. Animals on treatments containing cassava forage showed a positive nitrogen retention which increased linearly with the increased level of the forage, while negative nitrogen balances were recorded on the treatments containing Byparrhenia spp only. It was concluded that cassava would be a good source of protein supplementation during the dry season in tropical areas.