The endocannabinoid system in controlling feed intake and energy balance during the transition from late pregnancy to early lactation of dairy cows

内源性大麻素系统控制奶牛妊娠后期至泌乳早期采食量和能量平衡

• 批准号: 416735196
• 负责人: Privatdozent Dr. Björn Kuhla
• 金额: --
• 依托单位: Institut für Ernährungsphysiologie "Oskar Kellner"
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/416735196?language=en
• 关键词: endocannabinoid; system; controlling; feed; intake

During the transition from late pregnancy to early lactation, high producing dairy cows usually experience a negative energy balance due to insufficient increase in feed intake and the enormous energy requirements for milk production. As a consequence, mothers mobilize their body fat reserves, but as more fat is usually mobilized the lower is the postparturient increase in feed intake. Dams would benefit from an increased level of feed intake and reduced body fat mobilization to minimize deposition of mobilized fat in liver. So far, the effect of numerous metabolites and hormones on the reduction of feed intake has been described in literature, however, until today there is only marginal knowledge on endogenous signals significantly promoting feed intake of ruminants during the early lactation period. Prominent signaling stimulating feed intake while confining lipolysis is triggered through endocannabinoids. Among this substance class, N-arachidonoylethanolamine (AEA) has been described to exert one of the strongest feed intake stimulating effects. Therefore, the objective of the present project is to test the hypotheses that: 1. Endocannabinoids signal to promote feed intake postpartum, but high extent of fat mobilisation stimulate the degradation of endocannabinoids and thus their orexigenic action. 2. Intraperitoneal AEA administration improves energy balance of early lactating dairy cows by increasing feed intake involving increased hypothalamic orexigenic signaling and stimulation of lingual sweat taste receptors. 3. Peripheral AEA administration reduces lipolysis and increases lipogenesis in adipose tissue and mammary gland, thereby reducing liver fat content in early lactation. By pursuing these aims we expect to elucidate the physiological regulation of endocannabinoid-mediated signaling during the transition from late pregnancy to early lactation, and to depict ways of improving energy balance and health status of early lactating dairy cows.

在从妊娠晚期到泌乳早期的过渡期间，高产奶牛通常会经历负能量平衡，这是由于采食量增加不足和产奶的巨大能量需求。因此，母亲动员了她们的身体脂肪储备，但随着更多的脂肪通常被动员，产后采食量的增加就越低。水坝将受益于饲料摄入量的增加和体脂动员的减少，以最大限度地减少动员的脂肪在肝脏中的沉积。到目前为止，许多代谢产物和激素对减少采食量的影响已在文献中描述，然而，直到今天，只有边缘知识的内源性信号显着促进反刍动物在泌乳早期的采食量。 通过内源性大麻素触发显著的刺激摄食同时限制脂解的信号传导。在这类物质中，N-花生四烯酰乙醇胺（AEA）被描述为发挥最强的摄食刺激作用之一。因此，本项目的目的是检验假设：1。内源性大麻素发出信号，以促进产后摄食量，但高程度的脂肪动员刺激内源性大麻素的降解，从而促进其食欲。2.腹膜内AEA给药通过增加采食量改善早期泌乳奶牛的能量平衡，涉及增加下丘脑食欲信号传导和刺激舌汗味受体。3. 外周AEA给药减少脂肪分解，增加脂肪组织和乳腺中的脂肪生成，从而减少泌乳早期的肝脏脂肪含量。通过追求这些目标，我们希望阐明内源性大麻素介导的信号在从妊娠晚期到泌乳早期的过渡过程中的生理调节，并描述改善能量平衡和泌乳早期奶牛健康状况的方法。