Harnessing the dietary potential of cassava leaf and peel meals as novel feed resources in broiler nutrition.

Energy and protein are important in chicken diets, with maize and soybeans traditionally serving as primary sources. Rising costs of maize and soybean meal have necessitated the search for sustainable alternatives, such as abundant cassava peel meal (CPM) and cassava leaf meal (CLM). CPM is rich in carbohydrates, minerals, and fibre, while CLM has high levels of amino acids, vitamins, and carotenoids. Both are deficient in sulphur-amino acids (cysteine and methionine) but rich in lysine, an amino acid often lacking in cereal grains. Low inclusion levels (≤ 12.5% CPM or ≤ 5% CLM) improve broiler growth performance compared to conventional diets without negative effects on carcass yield, meat quality, organ weights, or blood parameters, while lowering feed costs and increasing gross margins. In contrast, higher inclusion levels (> 20% CPM or > 15% CLM) impair growth and blood indices, due to high fibre content, residual hydrogen cyanide (HCN), and other antinutritional factors (ANFs) like condensed tannins and phytates. Enzyme supplementation alleviates these adverse impacts and enhances nutrient utilisation, though outcomes vary with processing method, plant part used, diet composition, and inclusion rate. The practical implication of these findings is that diets containing cassava by-products require careful formulation, especially to balance the limiting sulphur-containing amino acids. Future research should optimise processing techniques and enzyme combinations to support higher inclusion levels and maximising the potential of these abundant resources.