• Physical examination of the animal: A bull needs to be able to see, smell and move around to successfully breed his share of the cows.
  • Reproductive organ examination: A thorough evaluation of the bull's reproductive organs should follow the general health examination. The spermatic cord, scrotum, testicles and other organs should be examined for evidence of injury, abscesses, frostbite damage or tumors.
  • Scrotal circumference: Because scrotal size correlates well with daily sperm production and is highly repeatable, scrotal circumference is a valuable indicator of semen production. Bulls with bigger testicles not only tend to produce more semen, they also sire sons with bigger testicles.
  • Semen quality: Sperm cell concentration, motility and morphology are evaluated and scored on the basis of a standard scoring system. Motility (or activity) of individual sperm cells is an important factor in determining the breeding soundness of bulls. Ideally, a semen sample should contain 90 percent or more vigorously motile sperm cells. The shape of the cells also is important. Abnormal cells should usually be less than 30 percent of the total.