An excellent aid to the herdsman’s visual observation program for detecting cows in standing heat.ย Apply to your cows prior to standing heat or when your cows are given injections to synchronize their estrus cycles.ย When cows are mounted during standing heat, the scratch-off surface of Estrus Alert is rubbed off exposing a brilliant red, fuchsia, blue or green signal layer underneath. Additional mountings result in increasing color exposure. Your cows are bred at the ideal time resulting in more pregnancies greatly improving your bottom line.