Fatty Acid Composition of Bovine Milk Fat as Influenced by Intravenous Infusion of Propionate or Glucose

The intravenous infusion of propionate in six Jersey cows resulted in decreased synthesis of all major milk fatty acids measured except :16:0, whereas infusion of glucose increased the secretion of 10:0 and 12:0, decreased that of 18:0, 18:1, and 18:2, and had little effect on 14:0 and 16:0. The data suggest that propionatc and glucose did not reduce milk fat secretion through the same mechanism. Comparison of changes in the fatty acid pattern with those associated with rationinduced milk fat depression indicates that the latter cannot be fully explained by the glucogenic effect of propionate.