Abstract The present review considers the impact of biotechnological fermentation methods as well as mechanical and hydrothermal processes in feed production, on the physical properties, chemical composition, starch and protein digestibility of poultry and pig feed. Reduction of feed particle size and consequently, gizzard underdevelopment in poultry and stomach ulceration in pigs coincide with fine grinding and are also reported as consequences of the common hydrothermal processes e.g. pelleting, expander processing and extrusion. Inclusion of structural feed components containing insoluble fibers with high resistance to grinding may partially counteract these negative impacts in pig and poultry. Hydrothermal processing (HTP) of poultry and pig feed improves the hygiene status of feed, reduces feed wastage, increases feed intake, reduces energy expenditure for ingestion of feed and may reduce allergenic proteins and anti-nutritional factors (ANFs). The impact of HTP on ileal starch digestibility is mainly negative for poultry and positive for pigs. In contrast to the current belief, the direct impact of HTP on chemical and physical properties of proteins in feed and their digestion per se is negligible and if any, it does not necessarily lead to better protein digestion. However, the more intensive hydrothermal processes i.e. expander processing and extrusion can improve protein and AA digestibility of poultry and pig feed through reduction of ANFs. Fermentation processes can effectively reduce ANFs in feed and modify the gut microbiota in pigs and poultry. However, the impact of the fermentation process on nutrient profiles of feed ingredients and their digestibility is rather inconsistent and largely depend on type of fermentation, incubation time, fermentation agent and enzymatic profile of dominant microorganisms in the fermentation process as well as type of feed ingredients and their chemical composition.

中文翻译：

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（生物）家禽和猪饲料的技术加工：对成分、消化率、抗营养因子和卫生的影响

摘要 本综述考虑了生物技术发酵方法以及饲料生产中的机械和水热过程对家禽和猪饲料的物理特性、化学成分、淀粉和蛋白质消化率的影响。饲料粒度的减小以及家禽的胼胝发育不全和猪的胃溃疡与细磨同时发生，也被报道为常见水热过程（例如制粒、膨胀机加工和挤压）的后果。包含具有高抗磨性的不溶性纤维的结构性饲料成分可以部分抵消这些对猪和家禽的负面影响。家禽和猪饲料的水热处理 (HTP) 改善了饲料的卫生状况，减少了饲料浪费，增加了采食量，减少摄入饲料的能量消耗，并可能减少过敏性蛋白质和抗营养因子 (ANF)。HTP 对回肠淀粉消化率的影响主要对家禽不利，对猪有利。与目前的看法相反，HTP 对饲料中蛋白质的化学和物理特性及其消化本身的直接影响可以忽略不计，如果有的话，它不一定会导致更好的蛋白质消化。然而，更密集的水热工艺，即膨胀机加工和挤压，可以通过减少 ANF 来提高家禽和猪饲料的蛋白质和 AA 消化率。发酵过程可以有效减少饲料中的 ANF，并改变猪和家禽的肠道微生物群。然而，