Effects of a Dietary L-Carnitine Supplementation on Performance, Energy Metabolism and Recovery from Calving in Dairy Cows

Abstract

Dairy cows are metabolically challenged during the transition period. Furthermore, the process of parturition represents an energy-consuming process. The degree of negative energy balance and recovery from calving also depends on the efficiency of mitochondrial energy generation. At this point, L-carnitine plays an important role for the transfer of fatty acids to the site of their mitochondrial utilisation. A control (n = 30) and an L-carnitine group (n = 29, 25 g rumen-protected L-carnitine per cow and day) were created and blood samples were taken from day 42 ante partum (ap) until day 110 post-partum (pp) to clarify the impact of L-carnitine supplementation on dairy cows, especially during the transition period and early puerperium. Blood and clinical parameters were recorded in high resolution from 0.5 h to 72 h pp. L-carnitine-supplemented cows had higher amounts of milk fat in early lactation and higher triacylglyceride concentrations in plasma ap, indicating increased efficiency of fat oxidation. However, neither recovery from calving nor energy balance and lipomobilisation were influenced by L-carnitine.

Dietary l-carnitine Supplementation Modifies the Lipopolysaccharide-Induced Acute Phase Reaction in Dairy Cows

“…Groups of cows were balanced for numbers of lactation, body weight (BW), body condition score (BCS) and fat-corrected milk yield of previous lactation. The impact of the dietary l -carnitine supplementation during the transition period, covering the time between days 42 ap and day 110 post-partum (pp), was published earlier (Meyer et al [ 4 ]).…”

“…The components and chemical compositions of roughages and concentrates were previously published by Meyer et al [ 4 ].…”

“…Clinical examinations of each cow were frequently performed from about 1 h ai until 72 h pi according to the methods of Dirksen et al [ 11 ]. Gathered clinical findings were evaluated by a cumulative clinical score (modified from Meyer et al [ 4 ]) by assigning the physiological level to 0 and deviations to increasing numbers ( Table A1 ). Finally, the individual scores were cumulated and related to the maximum possible score of 31 and then converted to percentages.…”

“…Equations used for the calculation of fat-corrected milk (FCM), energy-corrected milk (ECM), milk energy, net energy requirement for maintenance (NEM), net energy requirement for lactation (NEL), net energy balance (NEB), feed efficiency (FE), Revised Quantitative Insulin Sensitivity Check Index (RQUICKI) and anion gap were previously published by Meyer et al [ 4 ].…”

“…The dietary intake, endogenous synthesis and the reabsorption of l -carnitine including its precursors—N Ƹ –tri-methyl-lysine (TML) and y-butyro-betaine (yBB)—influence the l -carnitine status in mammals [ 2 ]. Different experiments indicated that an l -carnitine supplementation in the transition period of dairy cows supported the energy metabolism, more specifically the lipid metabolism as indicated by a decreased liver lipid accumulation and increased plasma triacyl-glyceride concentration (TG) [ 3 , 4 ]. Besides transition period, only limited information is available on the role of l -carnitine in other challenging, energy consuming situations in the life of dairy cows such as during an acute phase reaction (APR).…”