Open Access Document
Ceramides are a type of lipid that cause insulin resistance in non-ruminants. Dairy cows develop insulin resistance to support lactation, and ceramides are elevated during this time. Our objective was to determine the effects of ceramide synthesis inhibition on insulin resistance and milk production in cows. Ten Holstein dairy cows were ad libitum-fed for 2 d, followed by nutrient restriction (bedding straw, wheat bran, and minerals only) for 2 d. Concurrently, cows were intravenously infused with the serine palmitoyltransferase inhibitor, myriocin, (0.15 mg/kg BW/ d in 20% ethanol) or control (20% ethanol). In support of our hypothesis, myriocin lowered milk production compared to controls during nutrient restriction (P < 0.05). However, we were unable to measure insulin sensitivity due to unanticipated negative health outcomes resulting from nutrient restriction. Our findings may be confounded by an unexpected drop in feed intake in myriocin cows during ad libitum-feeding (P < 0.01).
Dairy cows, ceramides, lactation, insulin, Transformations