'Stray voltage' is an unclear term, but a commonly used term, when it comes to referring to electrical leakage in milking cowsheds and other milking structures. Voltage is the measure of the potential difference between two points and unless there is sufficient current being conducted between these two reference points then there won't be enough energy transferred between those two reference points to generate an electric shock. 'Stray power' is a better term or even better 'stray electrical leakage'. The voltage between the reference points multiplied by the current gives us the amount of 'power being used between those two reference points. In order for power to be used between those two points there must be a conductor for the power to flow through. In the case of 'stray voltage testing in cowsheds,' our reference points relate to two or more different conductive points on cows where leaking electricity can find a passage. The electricity finds a passage if there is sufficient voltage pushing a current through the animal between these surfaces. For dairy cows, milking goats and milking sheep these surfaces include; the soles of the hooves to the milk flowing out the udder, the soles of the hooves to the inside of the mouth, the inside of the mouth to the milk flowing out the udder and the soles of the front hooves to the soles of the hind hooves. These surfaces are significantly more sensitive and conductive than the cows coat or other appendages.

For example cows can receive 'shocks' between their hooves and udders via their milk, though out a milking if there is no earth bonding cable to the bail pipe work in a herringbone cowshed. There are several sources of electrical leakage that the cows can be exposed to seeing that without a bonding cable to the bail pipe work the cows are no longer earthed under their hooves. These sources include: returning electric fence leakage, three phase motor switching spikes and elevated 50 Hz AC leakage. This kind of shock can also happen on a rotary platform if the earth tracks in the central electrical coupling (gland) are dirty and are not earthing the platform adequately. Elevated leakage from these sources causes the cow stress. This stress can contribute to elevated somatic cell counts and increased instances of mastitis. 'Shocks' can also cause the cows to 'shit' excessively, lift their hooves, stomp and in bad cases 'kick' when being cupped. Very high leakage, above 12 volts can cause spontaneous teat sores and kill semen in the uterus effecting the number of empties and delayed conceptions.