We studied the effect of dietary linseed oil (LSO) supplementation and DGAT1 K232A (DGAT1) polymorphism on the triacylglycerol composition and crystallization of bovine milk fat. LSO supplementation increased unsaturated triacylglycerols, notably in the C52–C54 carbon range, while reducing the saturated C29–C49 triacylglycerols. These changes were associated with an increase in the low-melting fraction and the crystal lamellar thickness, as well as a reduction in the medium and high-melting fractions and the formation of the most abundant crystal type at 20 °C (β’-2 polymorph). Furthermore, DGAT1 KK was associated with higher levels of odd-chain saturated triacylglycerols than DGAT1 AA, and it was also associated with an increase in the high-melting fraction and the endset melting temperature. An interaction between diet and DGAT1 for the unsaturated C54 triacylglycerols accentuated the effects of LSO supplementation with DGAT1 AA. These findings show that genetic polymorphism and cows’ diet can have considerable effects on milk fat properties.

我们研究了膳食亚麻籽油 (LSO) 补充剂和DGAT1 K232A ( DGAT1 ) 多态性对牛乳脂肪的三酰甘油组成和结晶的影响。LSO 补充剂增加了不饱和甘油三酯，特别是在 C52–C54 碳范围内，同时减少了饱和 C29–C49 三酰甘油。这些变化与低熔点部分和晶层厚度的增加，以及中等和高熔点部分的减少以及 20 °C 下最丰富的晶体类型的形成有关（β'-2多态）。此外，与DGAT1相比， DGAT1 KK 与更高水平的奇数链饱和甘油三酯相关AA，并且它还与高熔点分数和末端熔化温度的增加有关。不饱和 C54 三酰甘油的饮食和DGAT1之间的相互作用加强了 LSO 补充DGAT1 AA 的效果。这些发现表明，基因多态性和奶牛的饮食会对乳脂特性产生相当大的影响。