Herbal Effects on Plasma Nutrients Metabolism in Heat Stressed Sheep

The quantitatification of bioactive components of plantain (PL, Plantago lanceolata L.) herb was performed by HPLC, and the superoxide anion radical (O2·-) scavenging activities (SOSA) were determined using ESR spectrometer. The [2H5]phenylalanine model was compared with the [1-13C]leucine method in order to pick out the feasible technique to determine whole body protein synthesis (WBPS) in sheep. Stable isotope dilution methods using [6, 6-2H]glucose, [1-13C]leucine, [1-13C]Na acetate and [U-13C]glucose were performed to determine the effects of PL on plasma glucose and acetate metabolisms, WBPS, and responses of plasma glucose metabolism to exogenous insulin in sheep during heat exposure. It could be concluded that the [1-13C]leucine isotope dilution method could be applied for the WBPS study without determining CO2 production in sheep. The PL played positive roles on plasma glucose, amino acid and acetate metabolisms, and most interestingly, the PL was found resistant to heat stress and hormone, insulin in sheep. The PL herb could be used as natural additive to ensure the quantity and quality of livestock products.