Abstract:

【Objective】 The effects of α-lipoic acid on serum fat metabolic parameters and liver enzyme activities in the transition cow were studied in an experiment. 【Method】 Forty-eight Holstein dairy cows at 20 d before calving were divided into four groups. Group Ⅰwas used as control. Group Ⅱto Ⅳ were fed with α-lipoic acid (3, 5 or 8 g•d-1) for 50 days. Blood samples were collected before the beginning of supplementation and at intervals of 10 days after supplementation. The following parameters indicative of fat metabolism and liver enzyme activities were measured in serum: triglyceride (TG), cholesterol (Chol), nonesterified fatty acid (NEFA), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and alkaline phosphatase (AKP), γ-glutamyl transferase (γ-GT), lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). 【Result】 Serum fat metabolic parameters showed a declining trend by α-lipoic acid treatment, but only serum NEFA concentrations were significantly changed on day 30 in group Ⅳ as compared with control group (P＜0.05). Serum AST activities were significantly lower on day 30 in groups Ⅱ, Ⅲ and Ⅳ than in control group (P＜0.05 or P＜0.01). There were no significant differences in other parameters between the treatment groups and the control. 【Conclusion】 It is concluded that α-lipoic acid supplementation can improve fat metabolism and protect liver function in the transition cow.

Key words: dairy cows, transition period, α-lipoic acid, fat metabolism, liver function