Bull Turnout Timing

Turnout date decides when your calves hit the ground, how even they run and how much labor you spend at calving. Pick the date on purpose, then get the bulls and the cows ready for it.

Key points

Work back from the calving window you want, since gestation is about 283 days.
Have a veterinarian perform a breeding soundness exam before turnout.
Cow body condition on the 1-to-9 scale affects how soon cows rebreed.
A defined breeding season gives more uniform calves and easier management.
Record dates and results so you can adjust next year.

Start with the calving date you want

Gestation runs roughly nine months, about 283 days, so every turnout date is really a calving date in disguise. Count forward from the day bulls go in and you know when the first calves will show up. Count back from the calving window that suits your grass, your weather and your workload.

Many ranchers aim calving at the time when cows are in good shape, the weather is kinder and the calves have feed coming. Your local extension office can tell you what works in your region, since forage growth and winter severity differ a lot from one place to the next.

Pick the calving window first, then work backward
Match calving to forage availability and weather
Think about when you can be present to watch heifers
Consider when you want to wean and sell calves

Get bulls ready weeks before turnout

A bull that goes out thin, sore or untested wastes a breeding season. Plan a health and fitness check well ahead of turnout so there is time to fix problems or bring in a replacement.

A breeding soundness exam by your veterinarian looks at the bull's reproductive tract, semen quality and physical soundness. Ask your vet how far ahead of turnout to schedule it for your operation, because semen quality takes time to change.

Book a breeding soundness exam with your vet
Check feet, legs, eyes and general condition
Bring body condition up gradually if he is thin
Review vaccination and parasite plans with your vet

Cow condition and heifer timing

Cows that calved recently need time to return to heat. Body condition score on the 1-to-9 scale is the practical tool here. Cows that are too thin at calving often rebreed late, and that pushes them further behind every year.

Heifers are usually bred ahead of the cow herd so they get extra time to recover and rebreed after their first calf. If you run heifers and cows together, think about whether the turnout date works for both groups.

Choosing the length of the breeding season

A shorter season gives a tighter calf crop, more uniform weaning weights and an easier calving period. A longer season is more forgiving but spreads calving out, and the late calves end up lighter at weaning.

The estrous cycle averages about 21 days, so a season is often described in cycles. Talk with your extension specialist about how many cycles fit your herd. If your herd has not been run on a defined season before, move toward one gradually rather than all at once.

Bull-to-cow ratios and pasture setup

How many cows one bull can cover depends on his age, his condition, the size and terrain of the pasture and how many bulls are in the group. There is no single number that fits every ranch, so ask your veterinarian or extension specialist for guidance that matches your setup.

Young bulls generally cover fewer cows than mature ones. Rough country with scattered cattle is harder on a bull than a small, open pasture. Make sure fences, water and shade are sound before turnout, because a bull that walks the fence is not breeding.

Common mistakes and what to ask

The usual errors are turning out bulls on a date chosen by habit, skipping the fertility exam, and leaving bulls with the cows long after the season should have ended. Another is ignoring the bull's condition until he has lost weight chasing cows.

Before turnout, ask your vet which exams to run, ask your extension office what calving window fits your area, and ask yourself whether you have the labor to handle calving when it arrives.

Did every bull pass a breeding soundness exam?
Are bulls in good condition and sound on their feet?
Is the end date for the season written down?
Do you have records to evaluate the season afterward?

Write it down and review it

Record turnout and pull dates, which bulls went with which groups and the calving dates that followed. Next year those records show whether the season was too long, whether a bull underperformed and whether the calving window needs to move.

When to get help: Call your veterinarian to schedule bull fertility exams and to review herd health before breeding. Your county extension office can help you choose a calving window and breeding season length that fit your region.

Sources and further reading

Organization homepages are linked so you can search them for current guidance on this topic.

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