Quick Answer
A rotational grazing fence system uses a permanent perimeter fence and moveable interior paddock divisions. The most practical setup: permanent high-tensile perimeter, temporary polywire interior cross-fencing moved every 3–7 days. For 40 acres with 100 cow-calf pairs, plan 6–8 paddocks allowing 4–6 days grazing per paddock and 30–45 days rest before re-entry. Place water centrally accessible from all paddocks.
System Design Principles
Paddock number: The minimum for effective rotational grazing is 6 paddocks — fewer paddocks don't allow enough rest for plant recovery. 8–12 paddocks is optimal for most operations, providing 40–70 day rest periods in the grazing season.
Paddock size: Size paddocks to provide the correct amount of forage for your herd at a 3–7 day grazing period. Stock density and forage yield per acre determine this calculation — consult your Extension agent for local stocking rate recommendations.
Lane system: A central lane 12–20 feet wide running through the property allows livestock to move between paddocks and provides equipment access without grazing the lane. Gates from the lane into each paddock make management simple.
Permanent vs. Temporary Interior Fencing
Permanent interior fencing: More expensive ($500–$1,200 per acre) but eliminates the labor of moving temporary fence. Best for operations with fixed paddock layouts that won't change based on forage conditions. Use high-tensile electric or woven wire.
Temporary interior fencing (most common): Polywire and step-in posts allow paddock size adjustment based on current forage conditions. Setup and move time: 30–60 minutes per paddock move for one person. Energizer can be portable or connected to the permanent perimeter system.
Water Access Design
Central water source accessible from all paddocks via the lane system is the most cost-effective approach. Alternatively, frost-free hydrants at two or three central points with troughs dragged to each paddock works for smaller operations. Avoid installing permanent water in every paddock — the infrastructure cost adds $300–$1,000 per paddock.
Cost Estimate
| Component | 40-Acre System | Cost |
|---|---|---|
| Permanent perimeter (HT electric) | 5,280 LF | $2,500–$5,000 |
| Portable interior system | 4 reels + 200 posts | $400–$800 |
| Solar energizer | 1 unit | $200–$400 |
| Central water system | 1 hydrant + 2 troughs | $500–$1,200 |
| Total | $3,600–$7,400 |
Our Recommendation
Start with 6–8 paddocks using temporary interior fencing on a solid permanent perimeter. This gives you flexibility to adjust paddock sizes as you learn your forage production patterns. After 1–2 seasons, identify which fence lines are permanent and which need to move seasonally — then upgrade those permanent lines to more durable materials. Don't try to build the perfect permanent system on day one.