Evaluation of mineral composition and in-vitro nutrient digestibility of macrophytes to assess their potential as sustainable animal feed

The current study evaluates the macro- and micro-mineral profiles, assesses heavy metal concentrations, and determines the in-vitro digestibility of various aquatic macrophytes collected from Dal Lake, Manasbal Lake, Hokersar Lake, and Anchar Lake. The macro-mineral analysis reveals significant variations among different species in each lake, highlighting the nutritional diversity of these aquatic plants. Lemna minor from Dal Lake, Azolla cristata from Manasbal Lake, Rumex rupestris from Hokersar Lake, and Lemna minor and Azolla cristata from Anchar Lake exhibited noteworthy macro-mineral concentrations. In terms of micro-minerals, Copper (Cu) concentrations were consistent among macrophytes from Dal Lake, while Fe levels were significantly higher (p < 0.05) in Nymphaea tetragona. The study found similar trends in micro-mineral concentrations in macrophytes from other lakes. The heavy metal analysis demonstrated varying concentrations among macrophytes in Dal Lake and Manasbal Lake, with some species showing potential as phytoremediators. The outcomes of in-vitro digestibility revealed significantly higher (p < 0.05) digestibilities of dry matter (DM), organic matter (OM), and neutral detergent fiber (NDF) in weeds Nelumbo nucifera, Trapa natans, and Lemna minor sourced from Dal Lake, whereas, Nymphaea tetragona from Manasbal Lake also revealed significantly higher values (p < 0.05). Significantly lower (p < 0.05) in-vitro digestibility values were revealed by Typha angustata, Nymphoides aquatica, and Ceratophyllum demersum from Nigeen Lake, likewise Nymphoides peltata sourced from Anchar Lake exhibited lower values. The study emphasizes the impact of environmental factors on mineral accumulation and the potential use of aquatic plants for nutrient removal and phytoremediation.