Effect of Chinese Herbs on Serum Biochemical Parameters, Immunity Indices, Antioxidant Capacity and Metabolomics in Early Weaned Yak Calves

Chinese traditional herbs are used widely as feed supplements to improve the immune response and antioxidant capacity of livestock. Twenty early-weaned 4-month-old yak calves (72.3 ± 3.65 kg) were divided randomly into four groups (n = 5 per group); three groups were provided with supplementary 80 mL/kg DMI of the root water extracts of either Angelica sinensis, Codonopsis pilosula or Glycyrrhiza uralensis, and one group (control) was not provided with a supplement. Compared to control calves, calves consuming the three herbal extracts increased serum concentrations of albumin (ALB) and glutathione peroxidase (GSH-Px), but decreased serum concentrations of free fatty acids (FFAs) and malondialdehyde (MDA) (p < 0.05). Calves consuming A. sinensis decreased (p < 0.05) serum concentration of total cholesterol (TC), and increased (p < 0.05) serum concentration of total proteins (TP). Serum FFA concentrations increased (p = 0.004) linearly with time in the control group, but not in the groups consuming herbs. Serum metabolomic data demonstrated that A. sinensis and C. pilosula regulate mainly amino acid metabolism, while G. uralensis regulates mainly carbon and amino acid metabolism. It was concluded that the three herbal root extracts, as dietary supplements, improved energy and nitrogen metabolism, and enhanced the antioxidant capacity of yak calves.