Polyunsaturated Protected Lipid: Effect on Triglyceride Molecular Weight Distribution

Abstract

Five lactating Holsteins were fed a polyunsaturated protected lipid supplement for 28 days. There were no significant changes in dry matter consumed or milk produced per cow per day. No changes in protein, solids-not-fat, and freezing point of the milk were significant. All cows increased from 22 to 34% in daily milk fat production. As expected, the fatty acid composition of the milk fat changed markedly during protected lipid feeding with increases in production of C4, C18:0, C18:l, C18:2, and C18:3 fatty acids. The production of triglyceride classes with 40, 52, and 54 fatty acid carbons also increased. Per day mammary production of the short chain fatty acids increased while the medium chain length fatty acid output decreased. This supports evidence by other researchers that two mechanisms of mammary synthesis are generating short and medium chain length fatty acids in milk fat. © 1980, American Dairy Science Association. All rights reserved.