Effects of storage temperature and time on fecal progesterone concentration in camel (Camelus dromedarius)

This study aimed to evaluate the effect of temperature (-20°C, + 4°C, room temperature) and storage time (7, 15, 107 and 173 days) of feces on progesterone concentration in camel (Camelus dromedarius). Plasma and feces were collected from 10 pregnant and one non-pregnant camels. Extraction of fecal metabolites of progesterone was performed with methanol and petroleum ether. The analytical validation was provided by internal quality control (IQC) and the success of the validation tests (sensitivity, precision, recovery and parallelism). In comparison to the value found in the day of collection, the mean concentration of progesterone in feces which was frozen or dried at room temperature showed no significant difference after 7 and 15 days. A significant increase was found for fecal samples stored at + 4°C. After 107 and 173 days, freezing is inadequate condition of storage because the fecal progestagen concentrations vary significantly. However, drying feces at ambient temperature maintained stable progestagen concentrations. Therefore, results indicated that drying feces is a reliable method, independent from an electric power source and the freezing equipment.