“When it comes to evaporative cooling most of the equipment problems we see are failures to do routine maintenance,” explained Tyler Marion, an engineer with Hog Slat Inc. located in Newton Grove, NC. “Evaporative cooling is really a pretty simple concept, but you have to perform basic maintenance tasks to keep the system operating correctly.”
Flush, Don’t Bleed
A standard industry practice involves “bleeding-off” a percentage of the recirculation water to prevent a buildup of scale on the pads. Scale is the mineral deposit left on the pad when the water evaporates. While bleeding-off is better than nothing, a much better practice is to dump all the water from the trough and replenish with fresh water that in turn helps to flush the containments out of the cool cell pads. How often the trough needs to be drained depends on the hardness of the water and how often the evaporative system operates. Monitoring the PH level is a useful method to determine when to change the water with readings above 8.5 indicating an excessive mineral buildup.
Use Preventive Chemical Treatments.
Paired with frequent water flushing, adding descalers and microbicides to the recirculating water pays big dividends in extending pad life. Descalers help keep minerals in suspension for more efficient flushing while microbicides reduce the growth and buildup of algae, bacterial and fungal slimes on the pads. Never use chlorine bleaches to kill algae. Chlorine attacks the glue in the pads causing delamination.
Adjust the Float.
One of the most common reasons for premature failure occurs when water logged pad bottoms become soft and sag down. Just because water doesn’t spill out of the trough when the system shuts down doesn’t mean the float is adjusted correctly. When properly set the water level should be 1″ below the bottom of the pads. It is critical to check the water level in new installations after running the system for several days.
Be on the lookout for trough levelness to change as the building settles and the framing shifts. Also, as the pads age, they retain more water making float valve adjustments necessary.
Clean the Trash Out
Trash and debris in the pump trap and water line filters reduce the amount of water circulating through the system. A telltale sign of reduced water flow is dry or streaked pads at the end opposite of the pump. Failing to remove debris from the trash basket on a jet pump also reduces its useful life. Clean the holes in the distribution pipe whenever dry streaks appear on the pad. Open the ball valve on distribution pipe opposite the pump end and run the system to flush out any gunk from inside the pipe at least once a month.
Winterize the System.
Shutting off the water supply and draining the system are the basics for preparing an evaporative system for winter. In addition, remove the pump from the system and move it to inside storage. Just disconnecting the plumbing fittings and leaving the pump in place leads to damaged impellers and cracked housings.
Performing basic maintenance allows evaporative cooling systems to operate efficiently and delays costly pad replacement.
Inappropriate or poorly maintained slatted floors are the most common causes of physical injuries to pigs. Pigs with foot or joint pain will not get up as often to eat and drink resulting in lower Average Daily Gain and reduced performance. The industry movement to group gestation housing also means better flooring is necessary to prevent injuries to heavy sows in open pens. By some estimates, lame sows can cost producers from $180 -$400 for each animal suffering from foot-related problems.
Well designed slats promoting good animal welfare possess several common characteristics. They are manufactured from high-density concrete, have a level, flat top for ease of walking and a uniform slat opening.
Manufacturing high quality begins with the slump of concrete. The less water added to the concrete, the stronger the slat. Dry-cast concrete, having a zero slump, only uses enough water to begin the chemical reaction. When excess water is added to make the concrete easier to form, the excess moisture evaporates; creating pores in the concrete and reduces its strength and durability. The lower cement-water ratio in dry cast slats yields a finished product with higher strength and durability with fewer repairs needed over its useful life.
Dry cast, machine-finished slat production requires fewer molds than comparable wet cast, hand-finished slats. Fewer molds mean less variation and a more consistent final product with a flat, level top and uniform slat openings.
The level surface provided by flat top slats reduces joint injuries from twisting and slipping on uncomfortable floors. Uniform slat openings prevent the pigs’ legs from getting caught in a narrowing opening and damaging their toes and claws.
Keep slats in good condition by using quick setting, abrasion resistant mortars to repair any exposed aggregates as normal wear occurs. Cover surfaces around feeders and waterers with an epoxy overlay coating to protect the concrete from acid compounds and heavy pig traffic. For more information on repairing concrete slats download “The Field Guide To Slat Repair and Replacement.”
Well made concrete slats and proper maintenance provide pigs and sows with comfortable flooring to reduce foot and leg injuries.
With the summer heat settling in it’s not uncommon for ventilation problems to start showing up in broiler houses and swine gestation/ breeding buildings. Even facilities that have performed well in the past may experience issues. One of the best yardsticks for evaluating a ventilation system is measuring wind speed. Windmeters ranging from an inexpensive smartphone unit to dedicated handheld devices are used to measure wind speed in feet per minute.
If the wind speed is lower than desired the next step is to check the static pressure with either a portable manometer or on the ventilation control monitor. With the ventilation system operating at full capacity, the house pressure should be between .05 to .08″. Some broiler facilities will experience higher pressure due to increased air requirements.
If the static pressure is high, the most likely cause is restricted airflow through cool cell pads clogged with scale or algae.
Scale is the buildup of minerals hard water leaves behind as it evaporates during the cooling process. Heavy deposits of scale require the use of a broom to dislodge the debris and then rinsing them off the pad with a low-pressure hose nozzle. The best way to deal with scale is to prevent it from forming in the first place. Adding a descaler treatment to the water helps keep the minerals in suspension and prevents them from sticking to the pad.
Nutrients in the water allow algae to grow and block the openings in the pad. Adding algaecides to the recirculating water kills the algae and prevents it from re-establishing. Allowing the pad to dry completely for several hours each day also stops algae growth.
But by far the most important management practice for cool cell maintenance is to drain and replace the water often. Even with the use of chemical agents, a build up of contaminants occurs in the trough. How often to replace the water depends on water quality and the amount of the time the system operates each day. Once a month is an absolute minimum during periods of heavy use to flush grit and dirt from the system.
If the static pressure is too low, the first reaction is to add fans to increase airflow. In many cases, especially in buildings where the airflow seemed adequate before, replacing the fan belts and/or pulleys will restore proper air flow. Slippage caused by worn belts and pulley cause fans to be less efficient and air delivery to suffer by as much as 20%. Plan to replace all fan belts on an annual basis with the metal pulleys needing replacement about every four years. A visual check after installing new belt should show the belt riding high in the pulley groove. If the belt sinks into the groove, then the pulley should be replaced.
Routine, scheduled maintenance on fans and evaporative systems is fundamental to providing broilers and pigs with adequate cooling during hot weather extremes.
By Austin Baker
Hog Slat Inc.
While LED lighting can bring broiler poultry growers significant energy savings, AgriShift® Dim-to-Blue® lighting offers more than being an environmentally friendly option. What makes AgriShift® Dim-to-Blue® technology uniquely beneficial, is that it is designed to influence and direct certain processes, recreating the best possible environment for your animal. New developments in LED lighting can now provide a customized light spectrum, intensity and photoperiod control for broiler environments. The utilization of this advanced LED lighting in broiler facilities can bring performance benefits, resulting in increased broiler production and improved animal welfare.
Three characteristics of lighting should be considered when designing a lighting system: 1) light spectrum or color of the light, 2) intensity of the light, and 3) photoperiod or the amount of time the lighting fixtures are on each day. In the past, lighting systems (incandescent, fluorescent or high-pressure sodium lamps) had fixed color and intensity, with the only controllable variable being the length of exposure. With ONCE® AgriShift® Dim-to-Blue® technology and lighting systems, it is possible to control all three key characteristics.
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AgriShift® Dim-to-Blue® lighting systems shift the spectrum to mimic a natural sunrise and sunset. With no dimming, the system produces a full light spectrum, ideal for stimulating growth when beginning a chicks growth cycle. As grow out continues the lighting is gradually decreased to 30%, shifting the range from blue to green to promote muscle growth. When the system is fully dimmed (also known as moon lighting), the monochromatic blue is used to calm the birds at night or before catching.
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Video tour of a 5000-sow farm located on a mountaintop near ShenNonh Dali in the Sichuan Province of China.
This remote sow unit produces and tests breeding stock from an 896 crate farrowing house, 4400 stall gestation building, 50 place boar stud, GDU/ Iso barn, and 15-room testing facility. Hog Slat designed the unit and supplied AirStorm fiberglass fans; feeding equipment including feed bins, sow drops, and Grow-Disk systems. Hog Slat’s SowMAX feed dispensers provide simple, dependable ad lib sow feeding in the farrowing crates.