Data_Sheet_1.ZIP

Abstract

This study aimed to monitor the effect of including rumen-protected L-carnitine ( Carneon 20 Rumin-Pro, Kaesler Nutrition GmbH, Cuxhaven, Germany) in the transition diet on the productive and metabolic responses of multiparous high producing Holstein dairy cows. Thirty-two multiparous cows were allocated in a completely randomized design to receive same diet plus 60 g fat prill containing 85% palmitic acid (control, n=16) or 100 g rumen-protected L-carnitine (RLC, n=16); at 28 d before expected calving until 28 days in milk (DIM). Fat prill was included in the control diet to balance the palmitic acid content of both experimental diets. Milk production over the 28 DIM for the control and RLC group was 46.5 and 47.7 kg, respectively. Milk fat content tended to increase upon rumen-protected L-carnitine inclusion (P= 0.1). Cows fed rumen-protected L-carnitine had higher fat and energy corrected milk compared with the control group. Pre- and post-partum administration of L-carnitine decreased both High and Low-density lipoprotein concentrations in peripheral blood of postpartum cows. Results of this study indicated that the concentration of triglycerides and beta-hydroxybutyrate was not significantly different between the groups. Whereas, blood non-esterified fatty acids concentration was markedly decreased in cows supplemented with L-carnitine. Animals in RLC group had significant (P< 0.05) lower blood haptoglobin concentration at 7 and 14 DIM than the control. Animals in the RLC group had lower concentration of blood enzymes than those of the control group. The mRNA abundance of Toll-like receptors 4, Cluster of differentiation 14 and myeloid differential protein 2 did not significantly changed upon the supplementation of L-carnitine in the transition diet. In summary, dietary inclusion of RLC improved dairy cow’s performance during early lactation period. Greater production, at least in part is driven by improved energy utilization efficiency and enhanced metabolic status in animals during the periparturient period.