CONDUCTIVITY OF DONKEY MILK

The electrical conductivity (EC) of milk is considered as one of the most important parameters which supports the diagnosis of mastitis in cows.Milk ions have a considerable influence on EC and their concentrations vary depending on animal species, season, lactation stage, etc. Some components of milk can change the EC, e.g. lactose. A negative correlation between EC values and the concentration of lactose is noticed, as a consequence of the inverse relation between this disaccharide and the chlorine content in milk. Fat and casein contents exert some influence on the EC, too. This study provides preliminary results on the physiological EC values in donkey milk and aims to highlight any correlation with some of its chemical-physical parameters and Somatic Cell Count (SCC). Mean EC value in donkey milk was found to be 3.57 mS. Statistically significant correlations were found between EC and SCC (r = 0.57 , p < 0.01) and between EC and (r = 0.30 , p < 0.05). The EC and lactose were not correlated although a reduction of EC was often observed when the lactose content increased, as reported in the literature for bovine milk. According to the EC can be considered as a reliable parameter to identify any breast disorder, taking into account the physiological factors that influence EC.