Responses of dairy cows to alternating electrical current administered semirandomly in a nonavoidance environment

Eight Holstein cows were assigned to two groups of four each, and a switchback design was used. Treatments were 4 mA of alternating current and no current. Four periods were each 96 h. Current was applied across subdermal electrodes, located on each cow's spine for 30 s, with a 30-s rest period between exposures for 5 min. Cows received current every 4 h for four 24-h intervals. No individual cow received current at the same time every day. Milk yield was reduced .16 kg/milking by exposure to 4 mA current. This decrease was not statistically significant. Percent milk fat and milk protein were not changed by current. Overall numbers of milk somatic cells were variable during the experiment. They increased during exposure to current, yet the increase was not statistically significant. Overall mean feed consumption and water consumption were not affected by treatments. The greatest behavioral response to current was upon initial exposure. Cows became accustomed to shock within 24 h of exposure. By the end of the fourth 96-h period of exposure, behavioral responses to current were almost extinct. We conclude that exposing cows to 4 mA of alternating current, in a semirandomized nonavoidance environment, for four consecutive 24-h intervals does not alter milk yield, milk composition, or intake of feed and water.