Economical method of preparing a teaser bull. Can spread venereal disease. Androgenized female Testosterone propionate injections before the breeding season or Synovex-H implants. Longer work life. Safer than bulls.
Injections are cheaper than surgically altering bull.
Androgenized cow can be one that lost her calf, thus there's no maintaining extra animals through winter. No disadvantages noted. Detecting estrus isn't enough to make an AI program a success. It is important to inseminate in a timely manner while ovulation is occurring. Ovulation occurs 26-32 hours after estrus starts, so researchers suggest that producers inseminate 12 hours after estrus observation.