Influence of intravenous L-carnitine administration in sheep preceding an oral urea drench.

Two experiments were conducted to investigate the effect of i.v. administration of L-carnitine on selected metabolites in sheep and to determine the feasibility of using L-carnitine to ameliorate the deleterious effects of hyperammonemia in sheep. In Exp. 1, i.v. L-carnitine solutions were administered at three levels in a replicated Latin square: 0 (CONT), 6.36 (CAR 1), and 12.72 (CAR 2) mmol L-carnitine/kg 75 BW using Suffolk ewes (n = 6; average BW 75 ± 3 kg). Plasma L-carnitine concentration was increased (P <.05) by treatment (51.9 vs 102.3, and 96.4 μmol/L in CONT, CAR 1, and CAR 2, respectively). Plasma glucose concentration was elevated (P <.05) in CAR 2 and CAR 1. Plasma NEFA concentration was highest ( P <.05) in CAR 2. Area under the response curve for glucose was greater (P <.02) in CAR 2. In Exp. 2, Suffolk ewes (n = 16; average BW 48 ± 2 kg) were used in a randomized complete block design with a 2 x 2 factorial treatment arrangement to determine the effects of i.v. L-carnitine administration during an oral urea load test (OULT). L-Carnitine (0 and 6.36 mmol/kg 75 BW) was administered i.v. at 30 min, and an oral urea drench (50% wt/vol; 0 and 300 mg/kg BW) was administered at 60 min. Plasma L-carnitine was increased (P <.0001) by i.v. L-carnitine. Plasma ammonia N was highest (P <.0001) in the UREA treatment compared with the CONT, CARN, and CARN + UREA treatments (148 vs 95, 101, and 108 μmol/L, respectively). Intravenous L-carnitine administration influenced plasma glucose and NEFA concentrations in sheep and, when administered 30 min preceding an OULT, prevented the development of subclinical hyperammonemia in sheep.