Quick changes of milk fatty acids after inclusion or suppression of linseed oil in the diet of goats.

BACKGROUNDLipid supplementation of ruminant diet is an excellent tool to improve the nutritional quality of dairy fat. The purpose of this research was to monitor in detail the goat milk fatty acid (FA) profile during the first 24h after linseed oil (LO) supplementation or suppression in the diet. Particular emphasis was placed in the changes of FA with bioactive properties. Milk fat was analysed by gas chromatography from milkings at 0, 1, 3, 6, 12 and 24h after diet shift. RESULTSThe -linolenic acid levels increased 12h after LO incorporation in the diet and decreased 3h after oil suppression. Most of the milk 10:0 to 16:0 saturated FA decreased 24h after LO supplementation, whereas oil suppression raised their levels after 6h. Similarly, raising of mono- and polyunsaturated trans-FA after LO inclusion was delayed in comparison with their decrease after oil suppression. CONCLUSIONThis study supports that ruminal bacteria and mammary glands would exhibit a fast responsiveness after the inclusion or suppression of LO in ruminant rations. Milk with an improved FA profile could be collected between 12h after LO supplementation and the last milking before LO suppression in the diet. (c) 2018 Society of Chemical Industry