Evaluation of the nutritional value and bioactive compounds of palm by-products and their potential use in the animal feed industry: in vitro study

The aim of this study was to evaluate the nutritional value and profiles of bioactive compounds as well as the in vitro digestibility of various palm by-products for potential use as animal feed ingredients. The nutrient composition, mineral content and bioactive compounds were determined in triplicate. In vitro digestibility and fermentation characteristics were evaluated for six samples of fronds or palm by-products and diets with different frond content. The results showed significant differences in the nutrient and mineral composition of the by-products. Rachis and fronds had higher fibre and minerals content, while date extract and dates without pits had higher carbohydrates content. Bioactive compounds, including amphetamine, caffeine and theophylline, were most abundant in fronds and by-product mixture. The digestibility of fronds and diet with 8% fronds (group B) were higher (p < .05). In addition, the concentration of propionic acid, butyric acid and total volatile fatty acids were higher in fronds and group B (p < .05). Methane (CH4) production and total gas production (TGP) were lower in frond-containing diets and TGP in the palm by-products mixture. These findings suggest that palm by-products have the potential to be valuable resources for the animal feed industry. However, further studies are needed to optimise their utilisation, ensure animal safety and determine the most suitable applications for the different by-products based on their specific composition.