The new year opened with oil prices hitting two year highs and the International Energy Agency (IEA) warning that high oil prices were posing a threat to the global economic recovery. Energy expenses are the single largest input cost for many large broiler producers. Reducing energy usage is an important way to improve net returns and, in light of the IEA’s warnings, examining ways of saving energy should be done sooner rather than later.
Following surveys of broiler grower costs in Georgia, US, a recent bulletin from the University of Georgia Cooperative Extension has identified a number of straightforward measures that growers can implement to help bring down utility expenses.
According to the bulletin, heating fuel and electricity costs can account for almost 60% of a typical contract broiler grower’s variable production costs. Dr Brian Fairchild, a University of Georgia Extension poultry scientist and one of the authors of the bulletin, notes that rising energy costs over the last decade have contributed to the need for growers to find more energy efficient means of heating and cooling their poultry houses.
“Contract growers recently have seen a considerable increase in the prices they pay for fuel and electricity, so there’s been a big push in the last six or seven years to conserve energy in broiler live production. The trick, however, is to do so without turning down the thermostat in the broiler house. Fortunately, almost everything we’ve done to reduce energy costs has also helped to actually improve the environment for the birds,” says Dr Fairchild.
Solid- and curtain-walls
In recent years there has been a trend toward solid wall construction for newer broiler houses. While there is little difference, according to the bulletin, in electrical cost data between solid- and curtain-wall houses, there is a significant difference in the usage of heating fuel, with solid-wall houses consuming considerably less propane.
In a study conducted by the authors, solid-wall houses used 0.0265 gal/ft2 of heating fuel per flock versus 0.0361 gal/ft2 per flock for curtain houses. This translates into an annual average saving for a solid-wall house of more than $2,100 per 20,000 ft2 of housing space.
The bulletin notes that rising fuel prices have further “encouraged producers to weatherproof and tighten houses to conserve energy”.
While the ranges of electrical cost data between the two housing types are similar, there is, within each type, a wide range of annual electrical costs.
For example, in curtain-sided houses, annual electrical costs ranged from $1,620 to $5,148/20,000ft2. Solid-wall houses showed a similar range. Even with other possible factors taken into account for variability in electrical usage, it was clear, say the authors, that “regardless of house type and growing conditions, (for) growers with electrical usages towards the high end of the range … it is highly likely (they) can improve their bottom line profitability by improving their ventilation methods.”
The authors suggest that growers can reduce use of electricity in their houses by:
- Cleaning fans, shutters and screens to help reduce the static pressure that fans are working against;
- Replacing burned out motors with energy efficient motors;
- Performing routine cleaning and maintenance on evaporative cooling pads – to reduce the static pressure that tunnel fans are working against; and
- Replacing incandescent light bulbs with more energy efficient bulbs.
Similarly, while solid-wall houses are more efficient than curtained houses, both can benefit from taking steps to maximize the benefit of fuel used. Among recommended measures are:
- Minimising air leakage. Tighter houses are easier and less costly to keep warm during cold weather;
- Conducting regular static pressure tests – low static pressure is an indication that air is leaking through cracks and holes;
- Using appropriate circulation fans – in winter, using fans to move warmer air towards the floor has the effect of improving air temperatures at bird level and increasing litter drying while reducing heater operation time;
- Installing insulated tunnel doors – helping to reduce heat loss near evaporating cooling pads. This alone, say the authors, can help to reduce fuel costs by 10% or more;
- Deploying migration fences – while normally used as a hot weather management tool, keeping birds spread out through the use of migration fences in the winter enables growers to use “bird heat” to minimize heater operation time, thus reducing energy and preventing overcrowding of birds.
A number of other measures were also suggested by the US researchers. They note that ventilation is a crucial component in achieving optimum bird performance and the importance of controlling ammonia levels during brooding. While this can be achieved through ventilation, it can be expensive if ammonia levels are high. Applying litter treatments for ammonia control can reduce the amount of cold air brought into the house to maintain air quality and subsequently reduce heating costs. Additionally, they note the damage that can be done to insulation, and reductions in tightness that can be caused, by darkling beetles and recommend a regular rotation program of treatment to keep darkling beetles as low as possible.
Attic inlets are also a good investment, the bulletin noted, however in order to work properly the house must be able to pull at 0.13” static pressure with one 48” fan. Fuel savings will vary depending on house tightness. In many cases, higher ventilation rates are achievable without having to increase fuel costs when the attic inlets are operated efficiently.
“By consistently practicing good energy management, broiler growers have the potential to significantly improve their energy usage and pare back utility costs,” said Dr Fairchild.