Bill Bergin of Roundup, Mont., created his own dark box for artificial insemination. By cutting a small hole in the front of the box, cattle enter calmly and easily. He attributes many AI successes this to the secret. The small light source naturally draws curious cows to the front of the box and keeps them calm while being inseminated.

Another tip: when breeding heifers, Mr. Bergin ties two old tires to the inside bars of the box (right) to contain the smaller animals. This keeps them from moving around, making his job easier