Delavaud C, Fougère H, Bertrand-Michel J, Bernard L
Université Clermont Auvergne, INRAE, VetAgro Sup, UMR Herbivores, Saint-Genès-Champanelle, France.
Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Inserm/Université Paul Sabatier UMR1048, Toulouse, France.
Animal. 2022 Dec;16(12):100635. doi: 10.1016/j.animal.2022.100635. Epub 2022 Nov 29.
This study examines the effects of diets supplemented with various lipids selected to induce divergent milk fat content responses (including a milk fat depression) between dairy cows and goats on plasma lipid composition. The objective was to better understand the mechanisms behind the regulation of milk fat secretion in these two ruminant species. Twelve Holstein cows and 12 Alpine goats were fed a basal diet not supplemented (CTL) or supplemented with corn oil plus wheat starch (COS, 5% DM intake (DMI)), marine algae powder of Schizochytrium sp. (MAP, 1.5% DMI), or hydrogenated palm oil (HPO, 3% DMI), in a replicated 4 × 4 Latin square design, during 28 days. On day 27, blood samples were collected for lipid analysis. Plasma lipid classes were quantified by high-performance thin-layer chromatography, with triacylglycerol (TAG) and free fatty acid (FFA) fractions analysed for FA composition by GLC. Plasma molecular species of TAG and ceramides were determined by HPLC-high-resolution MS and by liquid chromatography-triple quadrupole, respectively. Irrespective of diet, plasma total lipid content was higher in cows than goats (+61%), and TAG concentration was higher in goats than cows (+157%). In cows, conversely to goats, COS increased the trans-10 C18:1 proportion in the free FA (+248%) and the TAG (+195%) fractions. In cows and goats, MAP induced increases in cholesterol esters, cholesterol and phospholipids compared to CTL and changes in the plasma free FA and FA of TAG profiles. In both ruminant species, the concentrations of the lipid fractions were unchanged by HPO compared to CTL. Our results point to species specificities and different diet effects in plasma concentrations and compositions of lipid fractions in cows and goats. These new data highlight how diets, that induce large variations in milk fat secretions, affect the plasma lipid classes available for milk fat synthesis.
本研究考察了在奶牛和山羊日粮中添加不同脂质（这些脂质能诱导不同的乳脂含量反应，包括乳脂降低）对血浆脂质组成的影响。目的是更好地理解这两种反刍动物乳脂分泌调节背后的机制。采用重复的4×4拉丁方设计，给12头荷斯坦奶牛和12只阿尔卑斯山羊饲喂不添加（CTL）或添加玉米油加小麦淀粉（COS，占干物质采食量（DMI）的5%）、裂殖壶菌属海藻粉（MAP，占DMI的1.5%）或氢化棕榈油（HPO，占DMI的3%）的基础日粮，持续28天。在第27天采集血样进行脂质分析。血浆脂质类别通过高效薄层色谱法定量，三酰甘油（TAG）和游离脂肪酸（FFA）组分的脂肪酸组成通过气相色谱法分析。TAG和神经酰胺的血浆分子种类分别通过高效液相色谱 - 高分辨率质谱法和液相色谱 - 三重四极杆测定。无论日粮如何，奶牛血浆总脂质含量均高于山羊（+61%），而山羊的TAG浓度高于奶牛（+157%）。与山羊相反，在奶牛中，COS增加了游离脂肪酸（+248%）和TAG（+195%）组分中反式 - 10 C18:1的比例。与CTL相比，在奶牛和山羊中，MAP均导致胆固醇酯、胆固醇和磷脂增加，以及血浆游离脂肪酸和TAG脂肪酸谱的变化。与CTL相比，在两种反刍动物中，HPO均未改变脂质组分的浓度。我们的结果表明，奶牛和山羊在血浆脂质组分浓度和组成方面存在物种特异性和不同的日粮效应。这些新数据突出了诱导乳脂分泌大幅变化的日粮如何影响可用于乳脂合成的血浆脂质类别。
