The aim of this experiment was to investigate the effect of dietary supplementation of crushed high oleic sunflower seeds (HOS) and rumen‐protected choline (RPC) on the fatty acid (FA) profile of phospholipids and sphingomyelin and mammary transcription of genes that are important for milk fat synthesis and de novo synthesis of sphingolipids. Twenty‐four cows were divided into four groups that either received an unsupplemented diet (Control), the Control diet supplemented with 50 g RPC per day, a diet supplemented with HOS at 10% of dry matter, or RPC and HOS in combination (RPC + HOS). RPC supplementation had no effect on the FA composition of milk or sphingomyelin. Cows receiving RPC and RPC + HOS had increased incorporation of C22:5 (n‐3) into phospholipids. Milk FA proportion of C18:0 and C18:1 isomers was increased in cows receiving HOS (HOS and RPC + HOS). Sphingomyelin proportion of C22:0 was increased in cows receiving HOS and RPC + HOS, at the expense of C23:0. HOS supplementation further increased the proportion of unsaturated fatty acids (UFA) in milk phospholipids. HOS supplementation increased mammary transcription of UDP‐glucose ceramide glycosyltransferase (UGCG), sterol response element‐binding protein cleavage‐activating protein (SCAP) and peroxisome proliferation‐activated receptor Gamma subunit C 1b (PPARGC1b), and reduced transcription of insulin induced gene 1 (INSIG1) and fatty acid‐binding protein 3 (FABP3). Dietary supplementation of RPC increased mammary transcription of fatty acid desaturase 1 (FADS1) and longevity assurance gene 2 (LASS2), and reduced transcription of sphingomyelin synthase (SGMS). The results show that the FA profile of milk phospholipids is sensitive to dietary lipid supplementation and, to a minor degree, RPC supplementation. Furthermore, transcription of genes that are important for milk fat synthesis and sphingolipids synthesis is affected by dietary supplementation of RPC and HOS.

中文翻译：

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饲喂葵花籽和瘤胃保护胆碱的奶牛乳脂肪球膜长链脂肪酸组成及乳腺脂肪生成基因表达的变化。

本实验的目的是研究膳食补充压碎的高油酸葵花籽 (HOS) 和瘤胃保护胆碱 (RPC) 对磷脂和鞘磷脂的脂肪酸 (FA) 谱以及重要基因的乳腺转录的影响。用于乳脂合成和鞘脂的从头合成。24 头奶牛被分为四组，要么接受无添加日粮（对照），对照日粮每天补充 50 克 RPC，日粮补充 10% 干物质的 HOS，或 RPC 和 HOS 组合（RPC +居屋）。RPC 补充剂对牛奶或鞘磷脂的 FA 组成没有影响。接受 RPC 和 RPC + HOS 的奶牛增加了 C22:5 (n-3) 与磷脂的结合。C18:0和C18的牛奶FA比例：1 异构体在接受居屋 (居屋和 RPC +居屋) 的奶牛中增加。在接受 HOS 和 RPC + HOS 的奶牛中，C22:0 的鞘磷脂比例增加，以 C23:0 为代价。居屋补充剂进一步增加了牛奶磷脂中不饱和脂肪酸 (UFA) 的比例。HOS 补充剂增加了 UDP-葡萄糖神经酰胺糖基转移酶的乳腺转录（UGCG )、甾醇反应元件结合蛋白裂解激活蛋白 ( SCAP ) 和过氧化物酶体增殖激活受体 Gamma 亚基 C 1b ( PPARGC1b )，以及胰岛素诱导基因 1 ( INSIG1 ) 和脂肪酸结合蛋白 3 ( FABP3) 的转录减少）。膳食补充剂 RPC 增加了脂肪酸去饱和酶 1 ( FADS1 ) 和长寿保证基因 2 ( LASS2 ) 的乳腺转录，并减少了鞘磷脂合酶 ( SGMS ) 的转录）。结果表明，乳磷脂的 FA 谱对膳食脂质补充敏感，并且在较小程度上对 RPC 补充敏感。此外，对乳脂合成和鞘脂合成很重要的基因的转录受膳食补充剂 RPC 和 HOS 的影响。