A slide of bull semen shows curled tails, what do you do?

• A. Cull the bull
• B. Recheck in 60 days
• C. Retest in 1 week
• D. Do nothing

Answer: (B)

When a semen sample shows curled tails, you’re seeing a defect in sperm morphology that can reduce fertility, but one abnormal slide doesn’t prove a permanent problem. The key is to confirm with a recheck after a full spermatogenic cycle, because bulls take about 60 days to produce a new cohort of sperm. Waiting around 60 days gives a clear picture of the bull’s ongoing fertility, since that period accounts for production and maturation of fresh sperm. Rechecking in a week wouldn’t reflect a complete cycle and could mislead you, while doing nothing risks overlooking a real issue or prompting an unnecessary culling decision if the abnormality persists. If the second test still shows defects, you’d then weigh the next steps, but the correct move is to recheck after about sixty days to determine whether the problem is temporary or persistent.