Synergistic Bioconversion of Date Palm Leaves Into Ruminant Feed by a Leopard Moth ( <scp> <i>Zeuzera pyrina</i> </scp> L.) Gut Bacterial Consortium and Nutrient Stimulators

Date palm leaves (DPL), a widely available lignocellulosic by-product, are used as ruminant feed but are limited by high lignin and low protein content. This study evaluated the enhancement of DPL's nutritional value using a lignocellulose-degrading bacterial consortium (<i>Staphylococcus</i> sp., <i>Brevibacterium</i> sp., and <i>Enterobacter</i> sp.) isolated from the leopard moth (<i>Zeuzera pyrina</i> L.) gut, supplemented with microbial growth stimulators. Six treatments were applied: untreated DPL (control), DPL with M9 medium (T1), DPL with bacterial inoculum (T2), T2 + 0.5% glucose (T3), T2 + 0.5% urea (T4), and T2 + 0.5% glucose + 0.5% urea (T5). Parameters assessed included chemical composition, lignin peroxidase (LiP) activity, in vitro gas production (IVGP), fermentation characteristics, nutrient digestibility, and ruminal enzyme activities. LiP activity was highest in T5 (0.328 U/mL/min), representing a significant increase over controls. Inoculated treatments significantly reduced acid detergent lignin (ADL) and increased crude protein (CP), with T5 showing the greatest improvement: ADL decreased from 97.8 to 83.8 g/kg DM, and CP increased from 52.2 to 70.3 g/kg DM. T5 also exhibited the highest dry matter (DM) loss (61.1 g/kg DM), IVGP (61.2 mL), metabolizable energy (5.61 MJ/kg DM), short-chain fatty acid concentration (2.43 mmol/g DM), microbial protein synthesis (405 mg/g DM), and ammonia-N (10.2 mg/dL). Activities of carboxymethyl cellulase, microcrystalline cellulase, and filter paper-degrading enzymes were significantly elevated in all inoculated treatments, with T5 consistently yielding the highest values. These results demonstrate that co-application of the leopard moth gut-derived bacterial consortium with glucose and urea effectively delignifies DPL, substantially enhances its fermentability and nutritive value, and offers a sustainable strategy for valorizing agricultural residues in ruminant nutrition.