DAIRY COW SENSITIVITY TO SHORT DURATION ELECTRICAL CURRENTS

The results of 299 tests to determine the behavioral response threshold of dairy cows to a variety of shortduration or ‘transient’ electrical current waveforms via the muzzle to 4-hoof pathway are reported. The phase duration of stimuli tested ranged from 10 µs to 8.3 ms. Phase duration is defined as the time between two consecutive zero crossing points of the waveform (e.g., 1/2 cycle of a sinusoidal waveform). The amplitude of the electrical currents, at a given phase duration, were increased in an ascending series. The lowest threshold current at which an observer could detect a behavioral change was determined for individual cows. Various behaviors were quantified. Facial activity was the most sensitive behavioral response followed by front hoof lifting. Human observers measurements of hoof lifting agreed well with automated recording of animal motion. Tail motion showed no statistically significant response to the current stimulus. Cows were less sensitive (e.g., more current was required to elicit a response) to shorter duration or higher frequency waveforms. The strength-duration relationship observed for cows agreed well with neuro-electrical models previously verified by human response.