Leone Francesca, Ferrante Valentina
Department of Environmental Science and Policy, Università degli Studi di Milano, via Giovanni Celoria 10, 20133 Milan, Italy.
Department of Environmental Science and Policy, Università degli Studi di Milano, via Giovanni Celoria 10, 20133 Milan, Italy.
Sci Total Environ. 2023 Nov 25;901:165951. doi: 10.1016/j.scitotenv.2023.165951. Epub 2023 Aug 1.
This review aims to analyze the recent studies about prebiotics and precision biotics, as alternatives to animal growth promoters. These substances improve intestinal health, growth performance and poultry environmental impact. Prebiotics are insoluble fibers, that have no nutritive value, but they promote the growth of positive bacteria, increase the nutrients absorption and modulate the immune response. Instead, precision biotics are carbohydrates with glycosidic linkages, which interact with gut bacteria metabolism, reducing the excretion of nitrogen and consequentially, the poultry environmental impact. In the last years, different studies were published in this field, and for this reason, it is necessary to organize the results found. It was shown that mannan-oligosaccharides and β-glucans increase ileal nutrient digestibility, nitrogen retention and antibodies titers. Inulin, arabinoxylans-derived oligosaccharides, and galacto-oligosaccharides improved intestinal morphology, arranging for a larger absorption surface area. It was reported that prebiotics enhance the colonization of positive bacteria and can reduce the count of Campylobacter colonies. Furthermore, xylo-oligosaccharides are often used in animal feed, due to their ability to form organic acids, which decompose noxious substances, improving litter quality, and consequentially, reducing the environmental impact. Litter quality is a relevant aspect for ammonia emissions and for animal welfare. Whether the litter quality is poor, footpad dermatitis increase, worsening animal welfare and increasing nitrogen emissions to air. Precision biotics select metabolic pathways to modulate amino acid degradation, reintegrating the nitrogen discarded, and reducing the ammonia level in litter. It was also reported an improvement of growth performance and a better animal welfare. In conclusion, prebiotics and precision biotics can have positive effects on animal performance and welfare, and they can be a new strategy to reduce the environmental impact of chickens' farms.
本综述旨在分析近期有关益生元与精准益生元的研究，它们可作为动物生长促进剂的替代品。这些物质能改善肠道健康、生长性能并减轻家禽养殖对环境的影响。益生元是不溶性纤维，没有营养价值，但能促进有益菌生长，增加营养吸收并调节免疫反应。相反，精准益生元是带有糖苷键的碳水化合物，可与肠道细菌代谢相互作用，减少氮排泄，从而减轻家禽养殖对环境的影响。近年来，该领域发表了不同的研究，因此有必要梳理所获结果。研究表明，甘露寡糖和β-葡聚糖可提高回肠营养物质消化率、氮保留率和抗体滴度。菊粉、阿拉伯木聚糖衍生寡糖和低聚半乳糖可改善肠道形态，形成更大的吸收表面积。据报道，益生元可增强有益菌的定殖，并能减少弯曲杆菌菌落数量。此外，低聚木糖常用于动物饲料，因其能形成有机酸，分解有害物质，改善垫料质量，从而减轻对环境的影响。垫料质量对于氨气排放和动物福利而言是一个重要方面。如果垫料质量差，脚垫皮炎会增加，从而恶化动物福利并增加向空气中的氮排放。精准益生元选择代谢途径来调节氨基酸降解，重新利用废弃的氮，并降低垫料中的氨水平。另据报道，精准益生元还能提高生长性能并改善动物福利。总之，益生元和精准益生元可对动物性能和福利产生积极影响，它们可能成为降低养鸡场环境影响的新策略。
