The transition period of dairy cattle is characterized by a number of metabolic, endocrine, physiologic, and immune adaptations, including the occurrence of negative energy balance, hypocalcemia, liver dysfunction, overt systemic inflammatory response, and oxidative stress status. The degree and length of time during which these systems remain out of balance could render cows more susceptible to disease, poor reproductive outcomes, and less efficient for milk production and quality. Studies on both monogastrics and ruminants have reported the health benefits of nutraceuticals (e.g. probiotics, prebiotics, dietary lipids, functional peptides, phytoextracts) beyond nutritional value, interacting at different levels of the animal’s physiology. From a physiological standpoint, it seems unrealistic to disregard any systemic inflammatory processes. However, an alternate approach is to modulate the inflammatory process per se and to resolve the systemic response as quickly as possible. To this aim, a growing body of literature underscores the efficacy of nutraceuticals (active compounds) during the critical phase of the transition period. Supplementation of essential fatty acids throughout a 2-month period (i.e. a month before and a month after calving) successfully attenuates the inflammatory status with a quicker resolution of phenomenon. In this context, the inflammatory and immune response scenario has been recognized to be targeted by the beneficial effect of methyl donors, such as methionine and choline, directly and indirectly modulating such response with the increase of antioxidants GSH and taurine. Indirectly by the establishment of a healthy gastrointestinal tract, yeast and yeast-based products showed to modulate the immune response, mitigating negative effects associated with parturition stress and consequent disorders. The use of phytoproducts has garnered high interest because of their wide range of actions on multiple tissue targets encompassing a series of antimicrobial, antiviral, antioxidant, immune-stimulating, rumen fermentation, and microbial modulation effects. In this review, we provide perspectives on investigations of regulating the immune responses and metabolism using several nutraceuticals in the periparturient cow.

中文翻译：

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营养保健品在奶牛过渡时期的作用：综述。

奶牛的过渡期以许多代谢，内分泌，生理和免疫适应为特征，包括出现负能量平衡，低血钙，肝功能异常，明显的全身性炎症反应和氧化应激状态。这些系统保持不平衡的程度和时间长短可能会使奶牛更容易患病，繁殖结果差，并且奶产量和质量的效率降低。有关单胃和反刍动物的研究报告说，营养保健品（例如益生菌，益生元，饮食脂质，功能性肽，植物提取物）的健康益处超出营养价值，并在动物生理的不同水平上相互作用。从生理学的角度来看，忽略任何全身性炎症过程似乎是不现实的。但是，另一种方法是调节炎症过程本身，并尽快解决全身反应。为了这个目标，越来越多的文献强调在过渡时期的关键阶段，保健食品（活性化合物）的功效。在整个两个月的时间内（即产犊前一个月和产后一个月）补充必需脂肪酸可成功缓解炎症状况，并更快地解决问题。在这种情况下，已经认识到炎症和免疫应答场景是通过甲基供体例如蛋氨酸和胆碱的有益作用而靶向的，其直接和间接地通过增加抗氧化剂GSH和牛磺酸来调节这种应答。通过建立健康的胃肠道间接地，酵母和基于酵母的产品可调节免疫反应，从而减轻与分娩压力和随之而来的疾病相关的负面影响。植物产品的使用引起了广泛的关注，因为它们对多种组织靶标的作用范围广泛，包括一系列的抗微生物，抗病毒，抗氧化剂，免疫刺激，瘤胃发酵和微生物调节作用。在这篇综述中，我们为使用围产期母牛的几种保健食品调节免疫应答和代谢的研究提供了观点。植物产品的使用引起了广泛的关注，因为它们对多种组织靶标的作用范围广泛，包括一系列的抗微生物，抗病毒，抗氧化剂，免疫刺激，瘤胃发酵和微生物调节作用。在这篇综述中，我们提供了关于在围产期母牛中使用几种保健食品调节免疫应答和代谢的研究的观点。植物产品的使用引起了广泛的关注，因为它们对多种组织靶标的作用范围广泛，包括一系列的抗微生物，抗病毒，抗氧化剂，免疫刺激，瘤胃发酵和微生物调节作用。在这篇综述中，我们提供了关于在围产期母牛中使用几种保健食品调节免疫应答和代谢的研究的观点。