Incorporation of [hydrogen-3] alkylglycerolether and [carbon-14] hexadecanol into bovine colostrum and milk lipids.

[Hydrogen-3] glycerol ether and [carbon-14] hexadecanol were infused into the mammary gland or jugular vein of cows in colostral or full phases of lactation to determine their relative rates of synthesis and degradation. Neutral alkylglycerols were both synthesized and cleaved in the bovine gland. Oxidation of fatty alcohols and cleaving of neutral alkylglycerol ethers was faster during the milk than the colostral phase of lactation. In the colostral phase, both increased rate of synthesis and decreased cleavage contributed to increased neutral alkylglycerol concentration; however, synthesis changes were greater. Disappearance of [carbon-14] fatty alcohol and [hydrogen-3] alkylglycerol ether from the blood was the magnitude of fatty acid disappearance in previous studies, but uptake by the mammary gland was slower. Alkylglycerols were taken up from the blood and secreted intact into both colostrum and milk.