Seasonal weight loss (SWL) is a very important limitation to the production of ruminants in the Mediterranean and Tropical regions. In these areas, long dry seasons lead to poor pastures with low nutritional value. During the dry season, ruminants, particularly those raised in extensive production systems, lose around 30% of their body weight. Seasonal weight loss has important consequences on animal productive performance and health. In this study, RNA sequencing was used to characterize feed restriction effects in dairy goat of 2 breeds with different SWL tolerance: Majorera (tolerant) and Palmera (susceptible). Nine Majorera and ten Palmera goats were randomly distributed in a control and a restricted group: Majorera Control (adequately fed; MC; n = 4), Palmera Control (adequately fed; PC; n = 6), Majorera Restricted (feed restricted; ME; n = 5) and Palmera Restricted (feed restricted; PE; n = 4). On day 22 of the trial, mammary gland biopsies were collected for transcriptomics analysis. From these samples, 24,260 unique transcripts were identified. From those, 82 transcripts were differentially expressed between MC and ME, 99 between PC and PE, twelve between both control groups and twenty-nine between both restricted groups. Feed restriction affected several biochemical pathways in both breeds such as: carbohydrate and lipid transport; intracellular trafficking, RNA processing and signal transduction. This research also highlights the importance or involvement of the genes in tolerance (ENPP1, S-LZ, MT2A and GPNB) and susceptibility (GPD1, CTPS1, ELOVL6 and NR4A1) to SWL with respectively higher expression in the Majorera restriced group and the Palmera restricted group in comparison to the control groups. In addition, results from the study may be extrapolated to other dairy ruminant species.

中文翻译：

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了解奶山羊季节性减肥耐受性：转录组学方法。

季节性体重减轻（SWL）是限制地中海和热带地区反刍动物生产的重要限制。在这些地区，漫长的干旱季节导致草场贫瘠，营养价值低下。在干旱季节，反刍动物，特别是那些在大量生产系统中饲养的反刍动物，体重下降约30％。季节性减肥对动物的生产性能和健康有重要影响。在这项研究中，RNA测序被用于表征2种具有不同SWL耐受性的奶山羊的饲料限制作用：马约拉（耐）和帕尔梅拉（易感）。随机将9个马约拉山羊和10个帕尔梅拉山羊随机分为一个对照组和一个限制组：马约拉对照组（充分饲喂； MC； n = 4），帕尔梅拉对照（充分饲喂； PC； n = 6），马约拉限制饲养（饲喂受限； ME） ; n = 5）和Palmera限制（饲料限制； PE； n = 4）。在试验的第22天，收集乳腺活检样本进行转录组学分析。从这些样品中，鉴定出24,260个独特的转录本。从这些中，在MC和ME之间差异表达82个转录物，在PC和PE之间差异表达99个，两个对照组之间十二个，两个限制性组之间二十九个。饲料限制影响了两个品种的几种生化途径，例如：碳水化合物和脂质的运输；细胞内运输，RNA处理和信号转导。这项研究还强调了基因在耐受性（ENPP1，S-LZ，MT2A和GPNB）和易感性（GPD1，CTPS1，与对照组相比，在马约拉限制组和帕尔梅拉限制组中ELOVL6和NR4A1）至SWL的表达分别更高。此外，该研究的结果可能外推至其他奶牛反刍动物物种。