Goat diet supplementation with linseed oil (LO) can be a fruitful technological strategy to enhance the nutritional value of milk fat. The objective of the present study was to determine the effect of LO in a basal diet rich in starch on goat milk fatty acid (FA) profile. The FA contents were monitored exhaustively during 24 h after LO supplementation or elimination by gas chromatography. Rumenic acid, the main conjugated linoleic acid isomer and α-linolenic acid, both related with bioactive properties, significantly rose in milk between 12 and 24 h after the inclusion of LO in the diet. On the contrary, medium-chain saturated FA decreased. Changes in other nutritionally relevant milk FA as well as short term effects caused by dietary LO suppression are discussed.

Industrial relevance

Fortification of livestock feeds with lipid supplements is a technological approach that has attracted growing attention in order to change milk fatty acid (FA) profile. Enrichment of ruminant diets with linseed oil (LO) increases omega-3 FA and conjugated linoleic acid as well as decreases saturated FA in milk fat, which improves the nutritional value of dairy products. The present study explores the timing of those changes in the first 24 h after LO inclusion or suppression in the diet. We observed that changes of goat milk fat composition occurred for the most part between 12 and 24 h of LO supplementation, while those changes disappeared between 6 and 12 h after LO suppression. These results would be relevant for producers and industrialists in order to establish appropriate milk collection periods which provide an improved FA profile due to LO supplementation.

中文翻译：

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饲喂富含亚麻籽油的谷物基浓缩汁的山羊的营养相关牛奶脂肪酸的短期演变

用亚麻籽油（LO）补充山羊饮食可以成为提高乳脂营养价值的有效技术策略。本研究的目的是确定富含淀粉的基础饮食中的LO对山羊乳脂肪酸（FA）谱的影响。在补充LO或通过气相色谱法消除LO后的24小时内，对FA含量进行了详尽的监测。日粮中加入LO后的12至24小时内，与生物活性有关的瘤胃酸，主要的共轭亚油酸异构体和α-亚麻酸显着上升。相反，中链饱和脂肪酸减少。讨论了其他与营养相关的牛奶FA的变化以及饮食中LO抑制引起的短期影响。

行业相关性

用脂质补充剂强化家畜饲料的技术方法已引起越来越多的关注，目的是改变牛奶脂肪酸（FA）的特性。亚麻籽油（LO）丰富反刍动物饮食，可增加omega-3 FA和共轭亚油酸，并降低乳脂中的饱和FA，从而提高了乳制品的营养价值。本研究探讨了在饮食中加入或抑制LO后的最初24小时内这些变化的时机。我们观察到，补充LO的12至24小时之间，山羊奶脂肪成分的变化大部分发生，而抑制LO后的6至12小时，这些变化消失了。