When degrees hit extremes, 360 degrees prove an asset outdoors
Producers farrowing thier outdoor sows in the award-winning Rattlerow-designed Aardvark say they appear to cope better with extreme temperatures than those nursing litters in more traditional type accommodation.
During recent heat waves in June and July, some units reported internal temperatures inside traditional arks to be in excess of 40 degrees Celsius, while the temperatures recorded inside fully-insulated, dome-shaped Aardvarks and conventionally-shaped Armadillo (also plastic and of similar construction) were reported to be at least 10 degrees on the same site, at the same time of day.
Outdoor herd manager Rob McGregor has been farrowing sows in plastic huts for more than 8 years. The 900-sow herd he looks after still uses 50 traditional, twin-skinned metal/wooden farrowing arks, but they are being phased out in favour of Aardvarks and Armadillos. Rob says Techneat’s plastic huts have an edge over traditionally constructed ark, as their 60mm of refrigeration-grade insulation and automatic, climate controlled ventilation helps provide a more stabilised environment for sows to farrow in.
“Having total insulation, throughout the hut means the internal environment is well protected from external temperature fluctuations. Thermally speaking, the sow’s environment stays relatively stable in normal seasonal conditions. All our sows seem very comfortable all year round and we have hardly any condensation, which means beds stay dry and we don’t use that much straw,” says Rob.
When day time temperatures topped 29 degrees C on Rob’s 900-sow unit during June 2017, some of his traditional arks, particularly those in full sun, all day, saw internal temperatures top 40 degrees C, in spite of insulated roofs, heat reflective paint and all doors and rear vents fully opened. By comparison the fully insulated Armadillo and Aardvark huts were significantly cooler and provided a much more comfortable environment for sows and piglets.
“We don’t have any scientific data, but daily observations during a week-long of very extreme temperatures did indicate that sows housed in the traditional arks tended to struggle with these hot conditions. We saw sows panting, with visible signs of heat stress and unfortunately, we did have a few fatalities, too. But our sows housed in the plastic huts seemed much more comfortable, they behaved quite normally and we didn’t lose any from these huts. Freak weather certainly demonstrates the value of good insulation, it really cannot be underestimated,” says Rob.
A protected environment
Having refrigeration-grade insulation throughout the hut means the internal environment is well protected from external temperature fluctuations. These huts retain more warmth in cold conditions than traditional arks and thermal imaging surveillance from Rattlerow Farms outdoor units, taken in sub-zero temperatures during winter 2016/17, show that internal temperatures inside Aardvark huts were between 8 and 10 degrees Celsius higher than those recorded inside traditional, insulated metal/wooden arks on the same site, on the same day.
Techneat data from various outdoor sites shows traditional-type arks tend to continuously leak heat from uninsulated surfaces and lose temperature quickly when a sow exits to feed, drink, dung, whereas fully insulated plastic huts stay warmer for much longer periods after a sow exits – which is important as the sow is the primary heat source.
A comparative trial recently carried out by Tom Neat, managing director of specialist fabrication company Techneat, demonstrates the superior thermal properties of the Armadillo and Aardvark.
Both huts were placed into a sealed refrigeration unit at -5 degrees C along with a new, ‘high-spec’, twin-skinned, insulated(roof) metal/wooden traditional farrowing ark and monitored to find out how much energy was required to maintain the internal hut temperature at 7 degrees C.
The traditional ark was used as the ‘bench mark’ and deemed to require 100 units of the energy to maintain the set internal temperature. The results showed both plastic huts required at least half the amount of energy to maintain the same internal temperature (see graph below).
The composite design and total insulation of Aardvark and Armadillo huts means the internal environment is well protected from external temperature fluctuations – hence the internal temperature rises and/or falls gradually in response to outside conditions, creating a more stabilised environment with less risk from potential temperature shock.
There are also no ‘cold’ surfaces that warm air can condense on, so no condensation which can be problem with metal skinned arks.
A full report on Rob McGregor’s unit and his Aardvark/Armadillo experience is featured in Pig World August 2017.
- The Aardvark farrowing hut currently has a patent pending.
- It was awarded a first in the 2016 Pig and Poultry Fair’s Innovation Awards and was named Technical Innovation of the Year at the 2016 National Pig awards.