Multifunctional feed additives based on secondary plant raw materials as a system of metabolic correction in broiler chickens
Abstract
The study was conducted to comprehensively assess the potential of secondary plant materials (SPM) as a platform for multifunctional feed additives for broiler chickens. A systematic search covered 56 sources from 2019-2026 in PubMed, Google Scholar, and eLibrary. SPM (waste from oilseed crops, horticulture, winemaking, and grain processing) is characterised by high levels of polyphenols, dietary fibre, carotenoids, and organic acids. The mechanisms by which SPM components mediate metabolic correction include modulation of antioxidant status, regulation of intestinal microbiota composition, improvement of morphofunctional parameters of the gastrointestinal tract, immunomodulation, and a detoxifying effect. Metabolic correction is realized through activation of Nrf2-dependent antioxidant protection (increase in glutathione peroxidase and decrease in malondialdehyde at doses of grape seed extract of 100-500 mg/kg); modulation of intestinal microbiome (increase in Chao1 index by 24.6% when using fermented wheat bran, increase in Bacteroidota, Bacteroidia, Bacilli, Actinobacteriota, decrease in Clostridia, Gammaproteobacteria and Faecalibacterium when feeding 4 g/kg of pomegranate peel); improvement of intestinal condition (increase in villus height and villus/crypt ratio at doses of 30 g/kg of wheat bran, 1-4 g/kg of pomegranate peel, 5-10% of hemp cake); immunomodulation (decrease in IL-1β, IL-6, TNF-α at doses of grape seed extract of 200-400 mg/kg, stimulation of Ig G and M production at 1000 ppm of orange peel extract); aflatoxin B1 detoxification. Optimal doses for grain bran are 30 g/kg, for polyphenol extracts – 100-500 mg/kg, for oilcakes and pomace – 2-6%. Exceeding the recommended doses reduces productivity: 15-20% of camelina oilcake reduces live weight by 2.7-6.4%; 10% of rapeseed oilcake worsens protein digestibility by 2.38%, fat – by 4.42%, livability – up to 91.4%. The widespread spread of VRS is hampered by the variability of the chemical composition of raw materials, the presence of anti-nutritional factors, technological difficulties in processing wet waste, and the lack of standardised incorporation protocols.