Evaluation of two modified Butanol-HCl methodologies for the analysis of free condensed tannins in conjunction with their quantity occurrence in alfalfa (Medicago sativa L.) dried at various temperatures

摘要

Consumption of tannins, especially condensed tannins (CTs), have beneficial effects on animal production if ingested at a concentration of 20-50mg/g DM. Beneficial effects include increased growth rate of liveweight and wool, increased milk yields, fertility, utilisation of dietary proteins and animal welfare due to their bloat preventative activity and antiparasitic properties. However, elevated CT levels present in feed may lead to detrimental or fatal consequences. Medicago sativa L., commonly known as alfalfa, is one of the most nutritious preserved forage sources for livestock, although its CT concentration varies (Arrigo and Dohme, 2009). The effect of high-temperature drying on CTs has not been evaluated to date, so the aim of this study wasto investigate the free CT quantity occurrence and the effect of different forage drying procedures on free CT concentration in Medicago sativa L. based on two established Butanol-HCl assays due to contradictory results during preliminary experiments.