Abstract: A cow trainer hung from an electric wire has a disconnect switch between a metallic hanger bracket and a metallic stem or rod which carries the cow contact bar. The switch comprises an insulating sleeve having a bore in which one end of the stem slides. A pair of insulating hanger straps interconnect the sleeve and the stem whereby the weight of the stem and cow contact bar normally pull the straps to a fully extended position in which the end of the stem is in spaced relationship to the hanger bracket and out of electrical contact therewith. The straps yield upwardly when the stem is subject to upward movement when the cow humps her back, thus to permit the stem to slide upwardly in the bore and make electric contact with the hanger bracket and shock the cow.