Basics
Hoop structures represent an option for beef production which may avoid some pollution control issues while providing a suitable environment for efficient growth. A roofed structure eliminates runoff and increases control over manure nutrients. The main design issues included animal density, manure handling, feeding, animal handling, ventilation and cost.
The following images highlight some of the key features that make hoop structures innovative and technologically sound. These pictures come from the ISU demonstration site at Armstrong Research and Demonstration Farm near Lewis, Iowa (http://www.ag.iastate.edu/farms/armstrong.html). Scroll down to explore these features.
Figure 1. Hoop structures are constructed using steel arches mounted on wood or concrete sidewalls.
Figure 2. The steel arches are securely fastened to the sidewall to transmit the wind forces to the sidewalls and the ground.
Figure 3. A feed bunk was placed outside of the wall to eliminate the expense of an interior drive alley. An overhang was added to reduce the rainwater entering the bunk. One foot of bunk per head is provided.
Figure 4. A polyethylene/PVC fabric tarp is stretched over the steel framing to form the roof.
Figure 5. Tarps are designed to reflect solar radiation to prevent heat stress. White tarps tend to make the interior less dark.
Figure 6. A rain gutter was added to the overhang to channel rainwater away from the feed bunk.
Figure 7. Frost-free waterers are used near the bunks.
Figure 8. Concrete was sloped 1/2" per foot away from the bunk to help work manure away from the feed bunk.
Figure 9. Limestone screenings packed over geotextile materials can serve as a portion of the floor which will be scraped less and bedded more heavily.
Figure 10. To prevent the afternoon sun from penetrating deep into the building and causing heat stress, the west wall was enclosed.
Figure 11. Where building length is more than about 3 times its width, a ridge vent in the hoop structure helps to promote good airflow, reducing humidity during the winter and removing excess heat in the summer.
Figure 12. Lighting is sometimes used in hoops where animal care or inspection might occur after dark.
Figure 13. This diagram illustrates the cattle flow in the ISU research facility. Most farms would use one large pen instead of dividing it into three individual pens. This configuration allowed for moving cattle out of the way during cleaning and movement to a central processing area for normal management procedures.