High producing dairy cows generally receive in the diet up to 5–6% of fat. This is a relatively low amount of fat in the diet compared to diets in monogastrics; however, dietary fat is important for dairy cows as demonstrated by the benefits of supplementing cows with various fatty acids (FA). Several FA are highly bioactive, especially by affecting the transcriptome; thus, they have nutrigenomic effects. In the present review, we provide an up-to-date understanding of the utilization of FA by dairy cows including the main processes affecting FA in the rumen, molecular aspects of the absorption of FA by the gut, synthesis, secretion, and utilization of chylomicrons; uptake and metabolism of FA by peripheral tissues, with a main emphasis on the liver, and main transcription factors regulated by FA. Most of the advances in FA utilization by rumen microorganisms and intestinal absorption of FA in dairy cows were made before the end of the last century with little information generated afterwards. However, large advances on the molecular aspects of intestinal absorption and cellular uptake of FA were made on monogastric species in the last 20 years. We provide a model of FA utilization in dairy cows by using information generated in monogastrics and enriching it with data produced in dairy cows. We also reviewed the latest studies on the effects of dietary FA on milk yield, milk fatty acid composition, reproduction, and health in dairy cows. The reviewed data revealed a complex picture with the FA being active in each step of the way, starting from influencing rumen microbiota, regulating intestinal absorption, and affecting cellular uptake and utilization by peripheral tissues, making prediction on in vivo nutrigenomic effects of FA challenging.

中文翻译：

---

奶牛脂肪酸营养的进展：从肠道到细胞及其对生产性能的影响

高产奶牛日粮中的脂肪含量通常高达 5-6%。与单胃动物的饮食相比，饮食中的脂肪含量相对较低；然而，膳食脂肪对奶牛很重要，为奶牛补充各种脂肪酸 (FA) 的好处就证明了这一点。几种 FA 具有高度生物活性，特别是通过影响转录组；因此，它们具有营养基因组效应。在本综述中，我们提供了对奶牛对 FA 的利用的最新了解，包括影响瘤胃中 FA 的主要过程、肠道吸收 FA 的分子方面、合成、分泌和利用乳糜微粒；外周组织（主要是肝脏）对 FA 的摄取和代谢，以及受 FA 调节的主要转录因子。瘤胃微生物对FA的利用以及奶牛肠道对FA的吸收方面的大部分进展都是在上世纪末之前取得的，之后产生的信息很少。然而，过去 20 年，单胃动物在肠道吸收和细胞摄取 FA 的分子方面取得了巨大进展。我们通过使用单胃动物产生的信息并用奶牛产生的数据丰富它，提供了奶牛 FA 利用的模型。我们还回顾了日粮 FA 对奶牛产奶量、乳脂肪酸组成、繁殖和健康影响的最新研究。审查的数据揭示了一幅复杂的图景，FA 在每个步骤中都很活跃，从影响瘤胃微生物群、调节肠道吸收，到影响外周组织的细胞摄取和利用，这使得预测 FA 的体内营养基因组效应具有挑战性。