Abstract 265

Ravindran,-V; Kornegay,-ET; Rajaguru,-ASB; Potter,-LM; Cherry,-JA

Dep. Animal Science, Virginia Polytechnic Inst. and State Univ., Blacksburg, VA 24061, USA.

Poultry-Science. 1986, 65: 9, 1720-1727; 19 ref.

Eight feeding trials of 8 weeks duration were made to evaluate cassava leaf meal (CLM) as a replacement for coconut oil meal (COM) in tropical broiler diets. Diets containing 0, 10, 20, and 30% CLM that replaced COM were used in trials 1 and 2. Broiler performance was improved at the 10% CLM level. However, 20 and 30% levels of CLM resulted in depressions in gain, feed intake, and feed efficiency. Liver and spleen weights (percent of body weight) increased linearly with increasing levels of CLM. Carcass pigmentation values, as measured by Roche colour fan, favoured CLM-based diets. Results of trial 3 showed that broilers can tolerate a level of 15% CLM without adversely affecting their growth. In trials 4 and 5, supplementary methionine improved the gains of broilers given the 20% CLM diet but had no beneficial effect when added to the basal diet. All response criteria were improved when 3% soyabean oil was added to the basal or the 20% CLM diet in trials 6 and 7. Further addition of methionine had no effect on the performance of birds fed on the basal diet but improved growth of those fed on the 20% CLM diet. In trial 8, gains of broilers tended to decrease linearly with increasing levels of cyanide; however, gains were reduced only 4.6% at the highest level (200 mug/g) of added cyanide, and there were no deaths. In conclusion, the use of high level of CLM in broiler diets is limited by its bulkiness, low energy content, methionine deficiency, and the presence of antinutritional factors.