## 5 Animal Nutrition
For example, a study incorporated raw and fermented _Lenna polyrhiza_ leaf meal into diets for rohu fish (_Labee rohita_) fingerlings. Fermentation with a specific bacterial strain significantly reduced tannin (from 1.0% to 0.02%) and phytic acid (from 1.23% to 0.09%) levels. Fish fed diets with up to 30% fermented leaf meal exhibited improved growth performance compared to those fed raw leaf meal, indicating that fermentation effectively reduces ANFs and enhances nutritional value [124]. Other researchers have evaluated the impact of different types of duckweed batches (with _Lenna minuta_ and _Lenna minor_ (A, 17.5% crude protein), _Spirodela polyrhiza_ (B, 24.6% crude protein), and _Lenna obscura_ (C, 37.0% crude protein)) on broiler chickens, focusing on feed intake, body weight, and the ileal digestibility of amino acids and phosphorus [111]. Studies have shown that there are significant differences in the standardised ileal digestibility of crude protein and amino acids among different batches of duckweed, primarily due to variations in the nutrient composition and levels of antinutritional factors in different species of duckweed [111]. Furthermore, the growth environment of duckweed, such as carbon dioxide concentration and microorganisms, can also affect its nutrient composition [125]. Research has found that duckweed has higher protein content in its leaves under high carbon dioxide concentration and suitable nutrient supply conditions, but this high concentration may have a feedback inhibitory effect on certain nutrients. Furthermore, the rapid growth rate of duckweed, which can double in biomass in less than 30 hours under optimal conditions, may present unique challenges in terms of maintaining consistent quality and bioactive compound profiles [57]. In-depth understanding of the bioaccessibility and bioavailability of duckweed's bioactive compounds, as well as the optimisation of cultivation and processing methods, can unlock the full potential of this aquatic plant as a functional food source. Factors influencing the digestion rate of nutrients and the bioavailability of bioactive compounds in duckweed are crucial for the conversion of duckweed into food resources for human consumption and raw materials for animal feed. Understanding the factors that affect the digestion rate of nutrients and the bioavailability of bioactive compounds is helpful in developing more effective food processing methods and nutritional supplementation strategies, providing a theoretical basis for optimising feed/food formulations and improving feed/food processing techniques in animal feeding and human consumption [14; 114]. Possible Technological Solutions for Improving Protein Digestibility and Bioaccessibility of Bioactive Compounds in Duckweed  
Duckweed, a small floating aquatic plant, has garnered significant attention as a potential source of protein, vitamins, and other valuable compounds [125]. However, the efficient extraction and utilisation of these compounds from duckweed can be challenging due to the plant's cellular structure and composition [126], along with antinutritional factors. Improving protein extraction yields from comparatively sustainable aquatic biomass (microalgae, seaweeds, aquatic plants) is the present focus of the food industry. [PERSON] et al. (2022) mentioned that protein extraction from microalgae is quite challenging due to the presence of pigments and polysaccharides in the protein due to cell disruption, hence requiring a proper purification process. Similarly, during the extraction of protein from seaweed, polysaccharides and phenolics are present as co-extracted compounds and interact with seaweed proteins [127].