Biotechnological upgrading of palm kernel meal for poultry nutrition: Challenges and opportunities.

In recent years, fluctuations in the cost of traditional feed ingredients for poultry farming have compelled producers to explore alternative raw materials to reduce costs. Palm kernel meal (PKM), a by-product of the palm oil extraction industry, is one such alternative. Although PKM is often deemed a low-quality ingredient for poultry feed due to its low energy density and high content of non-starch polysaccharides, particularly β-mannans, its availability and lower price relative to other meal products make it a viable option. This review highlights the nutritional challenges and demonstrates how biotechnology can convert a cumbersome waste product into a valuable feed ingredient. The data focuses on the use of exogenous enzymes, with an emphasis on the synergistic action of β-mannanases and multicarbohydrase cocktails. The use of solid-state fermentation (SSF) with fungal and bacterial strains was also discussed. These bioprocesses efficiently break down complex fibrous matrices, increase the content of crude protein through microbial biomass synthesis and release bioactive manno-oligosaccharides (MOS) in situ. In vivo studies demonstrate that incorporating processed PKM maintains and improves production performance. The released MOS act as prebiotics, stimulating the growth of beneficial gut bacteria, preventing the growth of pathogens, and improving intestinal mucosal architecture. Although biotechnological valorization offers a promising way to transform PKM into a high-value functional ingredient for poultry feed, this technology has certain limitations. These include substrate variability and high scaling costs. Further research is needed into industrial-scale SSF processes, as well as the optimization of eco-efficient enzyme combinations and sequential fermentations.