Testing tunnel ventilation for turkeys
A company-owned research farm evaluates the merits of tunnel ventilation and other equipment innovations for Prestage Farms, S.C.
While tunnel ventilation has become the industry standard for broiler housing in the U.S., the turkey industry has been much slower to adopt this technology. But, some turkey growers in several states working with at least eight different integrators now employ tunnel ventilation.
Prestage Farms, S.C., recently completed a major building program in which 96 finisher houses were constructed. The 88 houses built by contract growers all rely on natural ventilation, but eight company-owned houses were built with evaporative cooling pads and tunnel ventilation.
The Prestage Farms, S.C., grow out operation is quite unusual for the turkey industry. It was built from scratch in just a few years in the mid-1990s, it has all single-age farms, it was designed around brood and move, and all of the 432 finisher houses have identical dimensions. Dr. Ron Prestage, president, Prestage Farms, S.C., said that he decided to stick with natural ventilation when the company underwent its recent expansion, but that he wanted to test tunnel ventilation to see if it would pay for itself in the future.
Prestage Farms’ has experience with tunnel ventilation in its swine operations and in some of its North Carolina turkey houses. But, Prestage wants to make sure that tunnel ventilation pays off in South Carolina before recommending that growers invest in the technology.
3 torpedoes farm
In June 2007, Prestage Farms, S.C., bought an existing 8,000 sow farm not far from the company’s Cassatt, S.C., feed mill. On one corner of this farm, the company built the 3 torpedoes turkey farm. The farm’s name comes from a childhood nickname given to the Prestage brothers, Ron, Scott and John, by their parents. The purpose of the farm’s eight finisher houses, besides housing turkeys, is to test the merits of adopting new technologies for finishing heavy toms.
All of the finisher houses in the company’s South Carolina complex are 50 feet wide and 400 feet long and have floor to ceiling sidewall curtains. The houses rely on natural ventilation supplemented with some 36-inch fans on the sidewall blowing across the house to move air in hot weather. The houses all have foggers to provide evaporative cooling.
One rule of thumb for tunnel ventilation is that you want your air-speed to be fast enough so that the air in the house is turned over each minute, this keeps the temperature pickup through the house to 5 F or less. This means that a 500-foot-long house needs airspeed of at least 500 feet-per-minute. Work with heavy broilers has shown some benefit to air speeds higher than 600 feet-per-minute, particularly as the birds approach market age.
Lots of airspeed
Prestage Farms has a target live weight for its toms of 40 pounds. As the birds approach market weight, there are a lot of BTUs of heat that need to be removed and exhausted out of the house. Each 3 torpedoes house has ten 51-inch and two 36-inch Aerotech fans. Tom Smith, grow out manager, Prestage Farms, S.C., said that these can produce and airspeed of 700 feet-per-minute in full tunnel mode. Evaporative cooling pads and tunnel doors are also installed on each house.
Even though the houses are curtain-sided, Smith said that the houses are operated as power ventilated houses, when not in tunnel-mode, with air drawn into the house through soffit vents and/or attic vents depending on the season of the year and age of the flock.
Birds are moved into the finisher houses from the brooder farm at five weeks of age in the Prestage complex. Because of the mild South Carolina winters, the finisher houses do not have heaters, but 3 torpedoes’ attic vents allow for the solar energy captured in the attic to be used to temper outside air prior to it being brought into contact with the birds.
Heavy toms and nipple drinkers
Nipple drinkers have become common place in turkey brooder houses. The same benefits have been recognized with turkeys as were found by broiler growers a decade earlier. Bell drinkers are still the standard drinker in use in turkey finisher houses in the U.S., but new adult turkey drinkers may change this. Lubing’s EasyLine turkey drinkers are used at 3 torpedoes farm and by many of Prestage Farm’s contract growers as well. These drinkers provide heavy toms with adequate water to support a 40 pound bird while helping to maintain litter and water quality at higher levels with less labor invested by the grower.
The possible impact of having two feed lines in a 50-foot-wide house is also being tested at 3-torpedoes. Each house has two Choretime feed lines instead of one, providing double the number of feed pans and reducing the distance that a bird has to walk to reach a feed pan. The feed lines are spaced roughly one third of the way across the house from the sidewalls.
Results not in yet
The first flock of birds at 3 torpedoes was placed on the farm in August of 2008. The first real test of the impact of the ventilation system on summertime performance will come this summer. Finisher farms in the South Carolina complex raise three flocks a year, so each farm will only have one “summer” flock per year, but research with broilers has shown benefits from tunnel ventilation in flocks raised in the spring and fall as well.
If you were designing a tunnel ventilated turkey house for heavy toms from scratch, you wouldn’t wind up with a design that matches the houses at 3 torpedoes. You would certainly make the houses longer and might even make them wider.
You might even make a house with solid-sidewalls. But, Ron Prestage explained that the concept behind 3 torpedoes was not to build the perfect turkey house, but rather to test the benefits and cost of adopting new technologies in the houses that his growers have. It will be interesting to see how these tests turn out.